From a152ffac94ce09baa2be3496f2cf62f2d7c33e02 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Thu, 6 Apr 2023 20:27:36 -0400
Subject: [PATCH 1/9] work

---
 packages/firestore/src/lite-api/reference.ts  | 117 +++++++++---------
 packages/firestore/src/lite-api/snapshot.ts   |  36 +++---
 .../firestore/src/lite-api/transaction.ts     |   3 +-
 .../src/lite-api/user_data_reader.ts          |  10 +-
 4 files changed, 80 insertions(+), 86 deletions(-)

diff --git a/packages/firestore/src/lite-api/reference.ts b/packages/firestore/src/lite-api/reference.ts
index 0a9fdcf71cd..fd47405efd2 100644
--- a/packages/firestore/src/lite-api/reference.ts
+++ b/packages/firestore/src/lite-api/reference.ts
@@ -41,14 +41,11 @@ import { FirestoreDataConverter } from './snapshot';
 import { NestedUpdateFields, Primitive } from './types';
 
 /**
- * Document data (for use with {@link @firebase/firestore/lite#(setDoc:1)}) consists of fields mapped to
- * values.
+ * Document data (for use with {@link @firebase/firestore/lite#(setDoc:1)}).
+ * Must be an object with string keys.
  */
-export interface DocumentData {
-  /** A mapping between a field and its value. */
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  [field: string]: any;
-}
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type DocumentData = Record<string, any>;
 
 /**
  * Similar to Typescript's `Partial<T>`, but allows nested fields to be
@@ -113,7 +110,7 @@ export type SetOptions =
  * and can be used to write, read, or listen to the location. The document at
  * the referenced location may or may not exist.
  */
-export class DocumentReference<T = DocumentData> {
+export class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /** The type of this Firestore reference. */
   readonly type = 'document';
 
@@ -129,7 +126,7 @@ export class DocumentReference<T = DocumentData> {
     /**
      * If provided, the `FirestoreDataConverter` associated with this instance.
      */
-    readonly converter: FirestoreDataConverter<T> | null,
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null,
     readonly _key: DocumentKey
   ) {
     this.firestore = firestore;
@@ -157,8 +154,8 @@ export class DocumentReference<T = DocumentData> {
   /**
    * The collection this `DocumentReference` belongs to.
    */
-  get parent(): CollectionReference<T> {
-    return new CollectionReference<T>(
+  get parent(): CollectionReference<AppType, DbType> {
+    return new CollectionReference<AppType, DbType>(
       this.firestore,
       this.converter,
       this._key.path.popLast()
@@ -175,7 +172,7 @@ export class DocumentReference<T = DocumentData> {
    * @param converter - Converts objects to and from Firestore.
    * @returns A `DocumentReference<U>` that uses the provided converter.
    */
-  withConverter<U>(converter: FirestoreDataConverter<U>): DocumentReference<U>;
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
   /**
    * Removes the current converter.
    *
@@ -183,10 +180,10 @@ export class DocumentReference<T = DocumentData> {
    * @returns A `DocumentReference<DocumentData>` that does not use a converter.
    */
   withConverter(converter: null): DocumentReference<DocumentData>;
-  withConverter<U>(
-    converter: FirestoreDataConverter<U> | null
-  ): DocumentReference<U> {
-    return new DocumentReference<U>(this.firestore, converter, this._key);
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(
+    converter: FirestoreDataConverter<NewAppType, NewDbType> | null
+  ): DocumentReference<NewAppType, NewDbType> {
+    return new DocumentReference<NewAppType, NewDbType>(this.firestore, converter, this._key);
   }
 }
 
@@ -194,7 +191,7 @@ export class DocumentReference<T = DocumentData> {
  * A `Query` refers to a query which you can read or listen to. You can also
  * construct refined `Query` objects by adding filters and ordering.
  */
-export class Query<T = DocumentData> {
+export class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /** The type of this Firestore reference. */
   readonly type: 'query' | 'collection' = 'query';
 
@@ -212,7 +209,7 @@ export class Query<T = DocumentData> {
     /**
      * If provided, the `FirestoreDataConverter` associated with this instance.
      */
-    readonly converter: FirestoreDataConverter<T> | null,
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null,
     readonly _query: InternalQuery
   ) {
     this.firestore = firestore;
@@ -224,7 +221,7 @@ export class Query<T = DocumentData> {
    * @param converter - `null` removes the current converter.
    * @returns A `Query<DocumentData>` that does not use a converter.
    */
-  withConverter(converter: null): Query<DocumentData>;
+  withConverter(converter: null): Query<DocumentData, DocumentData>;
   /**
    * Applies a custom data converter to this query, allowing you to use your own
    * custom model objects with Firestore. When you call {@link getDocs} with
@@ -234,9 +231,9 @@ export class Query<T = DocumentData> {
    * @param converter - Converts objects to and from Firestore.
    * @returns A `Query<U>` that uses the provided converter.
    */
-  withConverter<U>(converter: FirestoreDataConverter<U>): Query<U>;
-  withConverter<U>(converter: FirestoreDataConverter<U> | null): Query<U> {
-    return new Query<U>(this.firestore, converter, this._query);
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType> | null): Query<NewAppType, NewDbType> {
+    return new Query<NewAppType, NewDbType>(this.firestore, converter, this._query);
   }
 }
 
@@ -244,14 +241,14 @@ export class Query<T = DocumentData> {
  * A `CollectionReference` object can be used for adding documents, getting
  * document references, and querying for documents (using {@link (query:1)}).
  */
-export class CollectionReference<T = DocumentData> extends Query<T> {
+export class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> {
   /** The type of this Firestore reference. */
   readonly type = 'collection';
 
   /** @hideconstructor */
   constructor(
     firestore: Firestore,
-    converter: FirestoreDataConverter<T> | null,
+    converter: FirestoreDataConverter<AppType, DbType> | null,
     readonly _path: ResourcePath
   ) {
     super(firestore, converter, newQueryForPath(_path));
@@ -274,12 +271,12 @@ export class CollectionReference<T = DocumentData> extends Query<T> {
    * A reference to the containing `DocumentReference` if this is a
    * subcollection. If this isn't a subcollection, the reference is null.
    */
-  get parent(): DocumentReference<DocumentData> | null {
+  get parent(): DocumentReference<DocumentData, DocumentData> | null {
     const parentPath = this._path.popLast();
     if (parentPath.isEmpty()) {
       return null;
     } else {
-      return new DocumentReference(
+      return new DocumentReference<DocumentData, DocumentData>(
         this.firestore,
         /* converter= */ null,
         new DocumentKey(parentPath)
@@ -296,9 +293,9 @@ export class CollectionReference<T = DocumentData> extends Query<T> {
    * @param converter - Converts objects to and from Firestore.
    * @returns A `CollectionReference<U>` that uses the provided converter.
    */
-  withConverter<U>(
-    converter: FirestoreDataConverter<U>
-  ): CollectionReference<U>;
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(
+    converter: FirestoreDataConverter<NewAppType, NewDbType>
+  ): CollectionReference<NewAppType, NewDbType>;
   /**
    * Removes the current converter.
    *
@@ -306,11 +303,9 @@ export class CollectionReference<T = DocumentData> extends Query<T> {
    * @returns A `CollectionReference<DocumentData>` that does not use a
    * converter.
    */
-  withConverter(converter: null): CollectionReference<DocumentData>;
-  withConverter<U>(
-    converter: FirestoreDataConverter<U> | null
-  ): CollectionReference<U> {
-    return new CollectionReference<U>(this.firestore, converter, this._path);
+  withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
+  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType> | null): CollectionReference<NewAppType, NewDbType> {
+    return new CollectionReference<NewAppType, NewDbType>(this.firestore, converter, this._path);
   }
 }
 
@@ -330,7 +325,7 @@ export function collection(
   firestore: Firestore,
   path: string,
   ...pathSegments: string[]
-): CollectionReference<DocumentData>;
+): CollectionReference<DocumentData, DocumentData>;
 /**
  * Gets a `CollectionReference` instance that refers to a subcollection of
  * `reference` at the the specified relative path.
@@ -343,11 +338,11 @@ export function collection(
  * to a collection.
  * @returns The `CollectionReference` instance.
  */
-export function collection(
-  reference: CollectionReference<unknown>,
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: CollectionReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
-): CollectionReference<DocumentData>;
+): CollectionReference<DocumentData, DocumentData>;
 /**
  * Gets a `CollectionReference` instance that refers to a subcollection of
  * `reference` at the the specified relative path.
@@ -360,16 +355,16 @@ export function collection(
  * to a collection.
  * @returns The `CollectionReference` instance.
  */
-export function collection(
-  reference: DocumentReference,
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
-): CollectionReference<DocumentData>;
-export function collection(
-  parent: Firestore | DocumentReference<unknown> | CollectionReference<unknown>,
+): CollectionReference<DocumentData, DocumentData>;
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  parent: Firestore | DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
-): CollectionReference<DocumentData> {
+): CollectionReference<DocumentData, DocumentData> {
   parent = getModularInstance(parent);
 
   validateNonEmptyArgument('collection', 'path', path);
@@ -392,7 +387,7 @@ export function collection(
       ResourcePath.fromString(path, ...pathSegments)
     );
     validateCollectionPath(absolutePath);
-    return new CollectionReference(
+    return new CollectionReference<DocumentData, DocumentData>(
       parent.firestore,
       /* converter= */ null,
       absolutePath
@@ -417,7 +412,7 @@ export function collection(
 export function collectionGroup(
   firestore: Firestore,
   collectionId: string
-): Query<DocumentData> {
+): Query<DocumentData, DocumentData> {
   firestore = cast(firestore, Firestore);
 
   validateNonEmptyArgument('collectionGroup', 'collection id', collectionId);
@@ -429,7 +424,7 @@ export function collectionGroup(
     );
   }
 
-  return new Query(
+  return new Query<DocumentData, DocumentData>(
     firestore,
     /* converter= */ null,
     newQueryForCollectionGroup(collectionId)
@@ -452,7 +447,7 @@ export function doc(
   firestore: Firestore,
   path: string,
   ...pathSegments: string[]
-): DocumentReference<DocumentData>;
+): DocumentReference<DocumentData, DocumentData>;
 /**
  * Gets a `DocumentReference` instance that refers to a document within
  * `reference` at the specified relative path. If no path is specified, an
@@ -468,11 +463,11 @@ export function doc(
  * a document.
  * @returns The `DocumentReference` instance.
  */
-export function doc<T>(
-  reference: CollectionReference<T>,
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: CollectionReference<AppType, DbType>,
   path?: string,
   ...pathSegments: string[]
-): DocumentReference<T>;
+): DocumentReference<AppType, DbType>;
 /**
  * Gets a `DocumentReference` instance that refers to a document within
  * `reference` at the specified relative path.
@@ -485,16 +480,16 @@ export function doc<T>(
  * a document.
  * @returns The `DocumentReference` instance.
  */
-export function doc(
-  reference: DocumentReference<unknown>,
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
-): DocumentReference<DocumentData>;
-export function doc<T>(
-  parent: Firestore | CollectionReference<T> | DocumentReference<unknown>,
+): DocumentReference<DocumentData, DocumentData>;
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  parent: Firestore | CollectionReference<AppType, DbType> | DocumentReference<AppType, DbType>,
   path?: string,
   ...pathSegments: string[]
-): DocumentReference {
+): DocumentReference<AppType, DbType> {
   parent = getModularInstance(parent);
 
   // We allow omission of 'pathString' but explicitly prohibit passing in both
@@ -543,9 +538,9 @@ export function doc<T>(
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function refEqual<T>(
-  left: DocumentReference<T> | CollectionReference<T>,
-  right: DocumentReference<T> | CollectionReference<T>
+export function refEqual<AppType, DbType extends DocumentData>(
+  left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>,
+  right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>
 ): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
@@ -573,7 +568,7 @@ export function refEqual<T>(
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function queryEqual<T>(left: Query<T>, right: Query<T>): boolean {
+export function queryEqual<AppType, DbType extends DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
 
diff --git a/packages/firestore/src/lite-api/snapshot.ts b/packages/firestore/src/lite-api/snapshot.ts
index d726d92a7e4..d00086740bd 100644
--- a/packages/firestore/src/lite-api/snapshot.ts
+++ b/packages/firestore/src/lite-api/snapshot.ts
@@ -78,7 +78,7 @@ import { AbstractUserDataWriter } from './user_data_writer';
  * }
  * ```
  */
-export interface FirestoreDataConverter<T> {
+export interface FirestoreDataConverter<AppType, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /**
    * Called by the Firestore SDK to convert a custom model object of type `T`
    * into a plain Javascript object (suitable for writing directly to the
@@ -88,7 +88,7 @@ export interface FirestoreDataConverter<T> {
    * The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as
    * {@link (deleteField:1)} to be used as property values.
    */
-  toFirestore(modelObject: WithFieldValue<T>): DocumentData;
+  toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 
   /**
    * Called by the Firestore SDK to convert a custom model object of type `T`
@@ -102,9 +102,9 @@ export interface FirestoreDataConverter<T> {
    * omitted.
    */
   toFirestore(
-    modelObject: PartialWithFieldValue<T>,
+    modelObject: PartialWithFieldValue<AppType>,
     options: SetOptions
-  ): DocumentData;
+  ): PartialWithFieldValue<DbType>;
 
   /**
    * Called by the Firestore SDK to convert Firestore data into an object of
@@ -113,7 +113,7 @@ export interface FirestoreDataConverter<T> {
    * @param snapshot - A `QueryDocumentSnapshot` containing your data and
    * metadata.
    */
-  fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>): T;
+  fromFirestore(snapshot: QueryDocumentSnapshot<DbType, DbType>): AppType;
 }
 
 /**
@@ -125,7 +125,7 @@ export interface FirestoreDataConverter<T> {
  * access will return 'undefined'. You can use the `exists()` method to
  * explicitly verify a document's existence.
  */
-export class DocumentSnapshot<T = DocumentData> {
+export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   // Note: This class is stripped down version of the DocumentSnapshot in
   // the legacy SDK. The changes are:
   // - No support for SnapshotMetadata.
@@ -137,7 +137,7 @@ export class DocumentSnapshot<T = DocumentData> {
     public _userDataWriter: AbstractUserDataWriter,
     public _key: DocumentKey,
     public _document: Document | null,
-    public _converter: UntypedFirestoreDataConverter<T> | null
+    public _converter: UntypedFirestoreDataConverter<AppType, DbType> | null
   ) {}
 
   /** Property of the `DocumentSnapshot` that provides the document's ID. */
@@ -148,8 +148,8 @@ export class DocumentSnapshot<T = DocumentData> {
   /**
    * The `DocumentReference` for the document included in the `DocumentSnapshot`.
    */
-  get ref(): DocumentReference<T> {
-    return new DocumentReference<T>(
+  get ref(): DocumentReference<AppType, DbType> {
+    return new DocumentReference<AppType, DbType>(
       this._firestore,
       this._converter,
       this._key
@@ -161,7 +161,7 @@ export class DocumentSnapshot<T = DocumentData> {
    *
    * @returns true if the document exists.
    */
-  exists(): this is QueryDocumentSnapshot<T> {
+  exists(): this is QueryDocumentSnapshot<AppType, DbType> {
     return this._document !== null;
   }
 
@@ -172,7 +172,7 @@ export class DocumentSnapshot<T = DocumentData> {
    * @returns An `Object` containing all fields in the document or `undefined`
    * if the document doesn't exist.
    */
-  data(): T | undefined {
+  data(): AppType | undefined {
     if (!this._document) {
       return undefined;
     } else if (this._converter) {
@@ -187,7 +187,7 @@ export class DocumentSnapshot<T = DocumentData> {
       );
       return this._converter.fromFirestore(snapshot);
     } else {
-      return this._userDataWriter.convertValue(this._document.data.value) as T;
+      return this._userDataWriter.convertValue(this._document.data.value) as AppType;
     }
   }
 
@@ -226,17 +226,15 @@ export class DocumentSnapshot<T = DocumentData> {
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<
-  T = DocumentData
-> extends DocumentSnapshot<T> {
+export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *
    * @override
    * @returns An `Object` containing all fields in the document.
    */
-  data(): T {
-    return super.data() as T;
+  data(): AppType {
+    return super.data() as AppType;
   }
 }
 
@@ -247,12 +245,12 @@ export class QueryDocumentSnapshot<
  * number of documents can be determined via the `empty` and `size`
  * properties.
  */
-export class QuerySnapshot<T = DocumentData> {
+export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /**
    * The query on which you called {@link getDocs} in order to get this
    * `QuerySnapshot`.
    */
-  readonly query: Query<T>;
+  readonly query: Query<AppType, DbType>;
 
   /** @hideconstructor */
   constructor(
diff --git a/packages/firestore/src/lite-api/transaction.ts b/packages/firestore/src/lite-api/transaction.ts
index aab718cf91d..a1724ee0960 100644
--- a/packages/firestore/src/lite-api/transaction.ts
+++ b/packages/firestore/src/lite-api/transaction.ts
@@ -33,6 +33,7 @@ import { getDatastore } from './components';
 import { Firestore } from './database';
 import { FieldPath } from './field_path';
 import {
+  DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   SetOptions,
@@ -86,7 +87,7 @@ export class Transaction {
    * @param documentRef - A reference to the document to be read.
    * @returns A `DocumentSnapshot` with the read data.
    */
-  get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>> {
+  get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
     const ref = validateReference(documentRef, this._firestore);
     const userDataWriter = new LiteUserDataWriter(this._firestore);
     return this._transaction.lookup([ref._key]).then(docs => {
diff --git a/packages/firestore/src/lite-api/user_data_reader.ts b/packages/firestore/src/lite-api/user_data_reader.ts
index 0f869ca87e6..d384c6e3a79 100644
--- a/packages/firestore/src/lite-api/user_data_reader.ts
+++ b/packages/firestore/src/lite-api/user_data_reader.ts
@@ -76,13 +76,13 @@ const RESERVED_FIELD_REGEX = /^__.*__$/;
  * An untyped Firestore Data Converter interface that is shared between the
  * lite, firestore-exp and classic SDK.
  */
-export interface UntypedFirestoreDataConverter<T> {
-  toFirestore(modelObject: WithFieldValue<T>): DocumentData;
+export interface UntypedFirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData> {
+  toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
   toFirestore(
-    modelObject: PartialWithFieldValue<T>,
+    modelObject: PartialWithFieldValue<AppType>,
     options: SetOptions
-  ): DocumentData;
-  fromFirestore(snapshot: unknown, options?: unknown): T;
+  ): PartialWithFieldValue<DbType>;
+  fromFirestore(snapshot: unknown, options?: unknown): AppType;
 }
 
 /** The result of parsing document data (e.g. for a setData call). */

From a93a35397be0ebae30531bafd421b66af3a1da67 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 17 Apr 2023 15:06:24 -0400
Subject: [PATCH 2/9] done lite sdk

---
 packages/firestore/src/lite-api/aggregate.ts  | 28 +++----
 .../firestore/src/lite-api/aggregate_types.ts | 12 +--
 packages/firestore/src/lite-api/query.ts      | 54 ++++++------
 packages/firestore/src/lite-api/reference.ts  |  6 +-
 .../firestore/src/lite-api/reference_impl.ts  | 82 +++++++++----------
 packages/firestore/src/lite-api/snapshot.ts   | 28 ++++---
 6 files changed, 106 insertions(+), 104 deletions(-)

diff --git a/packages/firestore/src/lite-api/aggregate.ts b/packages/firestore/src/lite-api/aggregate.ts
index 0895d8f89c5..fc6de2d045c 100644
--- a/packages/firestore/src/lite-api/aggregate.ts
+++ b/packages/firestore/src/lite-api/aggregate.ts
@@ -32,7 +32,7 @@ import {
 import { getDatastore } from './components';
 import { Firestore } from './database';
 import { FieldPath } from './field_path';
-import { Query, queryEqual } from './reference';
+import {DocumentData, Query, queryEqual} from './reference';
 import { LiteUserDataWriter } from './reference_impl';
 import { fieldPathFromArgument } from './user_data_reader';
 
@@ -50,9 +50,9 @@ import { fieldPathFromArgument } from './user_data_reader';
  * retrieved from `snapshot.data().count`, where `snapshot` is the
  * `AggregateQuerySnapshot` to which the returned Promise resolves.
  */
-export function getCount(
-  query: Query<unknown>
-): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }>> {
+export function getCount<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  query: Query<AppType, DbType>
+): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>> {
   const countQuerySpec: { count: AggregateField<number> } = {
     count: count()
   };
@@ -87,10 +87,10 @@ export function getCount(
  * ```
  * @internal TODO (sum/avg) remove when public
  */
-export function getAggregate<T extends AggregateSpec>(
-  query: Query<unknown>,
-  aggregateSpec: T
-): Promise<AggregateQuerySnapshot<T>> {
+export function getAggregate<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  query: Query<AppType, DbType>,
+  aggregateSpec: AggregateSpecType
+): Promise<AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>> {
   const firestore = cast(query.firestore, Firestore);
   const datastore = getDatastore(firestore);
 
@@ -112,17 +112,13 @@ export function getAggregate<T extends AggregateSpec>(
   );
 }
 
-function convertToAggregateQuerySnapshot<T extends AggregateSpec>(
+function convertToAggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
   firestore: Firestore,
-  query: Query<unknown>,
+  query: Query<AppType, DbType>,
   aggregateResult: ObjectValue
-): AggregateQuerySnapshot<T> {
+): AggregateQuerySnapshot<AggregateSpecType, AppType, DbType> {
   const userDataWriter = new LiteUserDataWriter(firestore);
-  const querySnapshot = new AggregateQuerySnapshot<T>(
-    query,
-    userDataWriter,
-    aggregateResult
-  );
+  const querySnapshot = new AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>(query, userDataWriter, aggregateResult);
   return querySnapshot;
 }
 
diff --git a/packages/firestore/src/lite-api/aggregate_types.ts b/packages/firestore/src/lite-api/aggregate_types.ts
index ab9619b58b4..d668016efd9 100644
--- a/packages/firestore/src/lite-api/aggregate_types.ts
+++ b/packages/firestore/src/lite-api/aggregate_types.ts
@@ -19,7 +19,7 @@ import { AggregateType } from '../core/aggregate';
 import { ObjectValue } from '../model/object_value';
 import { FieldPath as InternalFieldPath } from '../model/path';
 
-import { Query } from './reference';
+import {DocumentData, Query} from './reference';
 import { AbstractUserDataWriter } from './user_data_writer';
 
 export { AggregateType };
@@ -71,7 +71,7 @@ export type AggregateSpecData<T extends AggregateSpec> = {
 /**
  * The results of executing an aggregation query.
  */
-export class AggregateQuerySnapshot<T extends AggregateSpec> {
+export class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /** A type string to uniquely identify instances of this class. */
   readonly type = 'AggregateQuerySnapshot';
 
@@ -79,11 +79,11 @@ export class AggregateQuerySnapshot<T extends AggregateSpec> {
    * The underlying query over which the aggregations recorded in this
    * `AggregateQuerySnapshot` were performed.
    */
-  readonly query: Query<unknown>;
+  readonly query: Query<AppType, DbType>;
 
   /** @hideconstructor */
   constructor(
-    query: Query<unknown>,
+    query: Query<AppType, DbType>,
     private readonly _userDataWriter: AbstractUserDataWriter,
     private readonly _data: ObjectValue
   ) {
@@ -101,9 +101,9 @@ export class AggregateQuerySnapshot<T extends AggregateSpec> {
    * @returns The results of the aggregations performed over the underlying
    * query.
    */
-  data(): AggregateSpecData<T> {
+  data(): AggregateSpecData<AggregateSpecType> {
     return this._userDataWriter.convertValue(
       this._data.value
-    ) as AggregateSpecData<T>;
+    ) as AggregateSpecData<AggregateSpecType>;
   }
 }
diff --git a/packages/firestore/src/lite-api/query.ts b/packages/firestore/src/lite-api/query.ts
index 3afa282048f..5d4bd9dee97 100644
--- a/packages/firestore/src/lite-api/query.ts
+++ b/packages/firestore/src/lite-api/query.ts
@@ -53,7 +53,7 @@ import {
 } from '../util/input_validation';
 
 import { FieldPath } from './field_path';
-import { DocumentReference, Query } from './reference';
+import {DocumentData, DocumentReference, Query} from './reference';
 import { DocumentSnapshot, fieldPathFromArgument } from './snapshot';
 import {
   newUserDataReader,
@@ -95,7 +95,7 @@ export abstract class AppliableConstraint {
    * Takes the provided {@link Query} and returns a copy of the {@link Query} with this
    * {@link AppliableConstraint} applied.
    */
-  abstract _apply<T>(query: Query<T>): Query<T>;
+  abstract _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType>;
 }
 
 /**
@@ -114,7 +114,7 @@ export abstract class QueryConstraint extends AppliableConstraint {
    * Takes the provided {@link Query} and returns a copy of the {@link Query} with this
    * {@link AppliableConstraint} applied.
    */
-  abstract _apply<T>(query: Query<T>): Query<T>;
+  abstract _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType>;
 }
 
 /**
@@ -131,11 +131,11 @@ export abstract class QueryConstraint extends AppliableConstraint {
  * @throws if any of the provided query constraints cannot be combined with the
  * existing or new constraints.
  */
-export function query<T>(
-  query: Query<T>,
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  query: Query<AppType, DbType>,
   compositeFilter: QueryCompositeFilterConstraint,
   ...queryConstraints: QueryNonFilterConstraint[]
-): Query<T>;
+): Query<AppType, DbType>;
 
 /**
  * Creates a new immutable instance of {@link Query} that is extended to also
@@ -147,18 +147,18 @@ export function query<T>(
  * @throws if any of the provided query constraints cannot be combined with the
  * existing or new constraints.
  */
-export function query<T>(
-  query: Query<T>,
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  query: Query<AppType, DbType>,
   ...queryConstraints: QueryConstraint[]
-): Query<T>;
+): Query<AppType, DbType>;
 
-export function query<T>(
-  query: Query<T>,
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  query: Query<AppType, DbType>,
   queryConstraint: QueryCompositeFilterConstraint | QueryConstraint | undefined,
   ...additionalQueryConstraints: Array<
     QueryConstraint | QueryNonFilterConstraint
   >
-): Query<T> {
+): Query<AppType, DbType> {
   let queryConstraints: AppliableConstraint[] = [];
 
   if (queryConstraint instanceof AppliableConstraint) {
@@ -205,17 +205,17 @@ export class QueryFieldFilterConstraint extends QueryConstraint {
     return new QueryFieldFilterConstraint(_field, _op, _value);
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
     const filter = this._parse(query);
     validateNewFieldFilter(query._query, filter);
-    return new Query(
+    return new Query<AppType, DbType>(
       query.firestore,
       query.converter,
       queryWithAddedFilter(query._query, filter)
     );
   }
 
-  _parse<T>(query: Query<T>): FieldFilter {
+  _parse<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): FieldFilter {
     const reader = newUserDataReader(query.firestore);
     const filter = newQueryFilter(
       query._query,
@@ -295,7 +295,7 @@ export class QueryCompositeFilterConstraint extends AppliableConstraint {
     return new QueryCompositeFilterConstraint(type, _queryConstraints);
   }
 
-  _parse<T>(query: Query<T>): Filter {
+  _parse<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Filter {
     const parsedFilters = this._queryConstraints
       .map(queryConstraint => {
         return queryConstraint._parse(query);
@@ -309,7 +309,7 @@ export class QueryCompositeFilterConstraint extends AppliableConstraint {
     return CompositeFilter.create(parsedFilters, this._getOperator());
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
     const parsedFilter = this._parse(query);
     if (parsedFilter.getFilters().length === 0) {
       // Return the existing query if not adding any more filters (e.g. an empty
@@ -318,7 +318,7 @@ export class QueryCompositeFilterConstraint extends AppliableConstraint {
     }
     validateNewFilter(query._query, parsedFilter);
 
-    return new Query(
+    return new Query<AppType, DbType>(
       query.firestore,
       query.converter,
       queryWithAddedFilter(query._query, parsedFilter)
@@ -435,7 +435,7 @@ export class QueryOrderByConstraint extends QueryConstraint {
     return new QueryOrderByConstraint(_field, _direction);
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
     const orderBy = newQueryOrderBy(query._query, this._field, this._direction);
     return new Query(
       query.firestore,
@@ -500,8 +500,8 @@ export class QueryLimitConstraint extends QueryConstraint {
     return new QueryLimitConstraint(type, _limit, _limitType);
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
-    return new Query(
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+    return new Query<AppType, DbType>(
       query.firestore,
       query.converter,
       queryWithLimit(query._query, this._limit, this._limitType)
@@ -564,14 +564,14 @@ export class QueryStartAtConstraint extends QueryConstraint {
     return new QueryStartAtConstraint(type, _docOrFields, _inclusive);
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
     const bound = newQueryBoundFromDocOrFields(
       query,
       this.type,
       this._docOrFields,
       this._inclusive
     );
-    return new Query(
+    return new Query<AppType, DbType>(
       query.firestore,
       query.converter,
       queryWithStartAt(query._query, bound)
@@ -671,7 +671,7 @@ export class QueryEndAtConstraint extends QueryConstraint {
     return new QueryEndAtConstraint(type, _docOrFields, _inclusive);
   }
 
-  _apply<T>(query: Query<T>): Query<T> {
+  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
     const bound = newQueryBoundFromDocOrFields(
       query,
       this.type,
@@ -751,10 +751,10 @@ export function endAt(
 }
 
 /** Helper function to create a bound from a document or fields */
-function newQueryBoundFromDocOrFields<T>(
-  query: Query,
+function newQueryBoundFromDocOrFields<AppType, DbType extends DocumentData>(
+  query: Query<AppType, DbType>,
   methodName: string,
-  docOrFields: Array<unknown | DocumentSnapshot<T>>,
+  docOrFields: Array<unknown | DocumentSnapshot<AppType, DbType>>,
   inclusive: boolean
 ): Bound {
   docOrFields[0] = getModularInstance(docOrFields[0]);
diff --git a/packages/firestore/src/lite-api/reference.ts b/packages/firestore/src/lite-api/reference.ts
index fd47405efd2..d00c2d47bb9 100644
--- a/packages/firestore/src/lite-api/reference.ts
+++ b/packages/firestore/src/lite-api/reference.ts
@@ -179,7 +179,7 @@ export class DocumentReference<AppType = DocumentData, DbType extends DocumentDa
    * @param converter - `null` removes the current converter.
    * @returns A `DocumentReference<DocumentData>` that does not use a converter.
    */
-  withConverter(converter: null): DocumentReference<DocumentData>;
+  withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
   withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(
     converter: FirestoreDataConverter<NewAppType, NewDbType> | null
   ): DocumentReference<NewAppType, NewDbType> {
@@ -538,7 +538,7 @@ export function doc<AppType = DocumentData, DbType extends DocumentData = AppTyp
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function refEqual<AppType, DbType extends DocumentData>(
+export function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
   left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>,
   right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>
 ): boolean {
@@ -568,7 +568,7 @@ export function refEqual<AppType, DbType extends DocumentData>(
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function queryEqual<AppType, DbType extends DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean {
+export function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
 
diff --git a/packages/firestore/src/lite-api/reference_impl.ts b/packages/firestore/src/lite-api/reference_impl.ts
index e478cc76eb4..7f20b93afa5 100644
--- a/packages/firestore/src/lite-api/reference_impl.ts
+++ b/packages/firestore/src/lite-api/reference_impl.ts
@@ -39,7 +39,7 @@ import { FieldPath } from './field_path';
 import { validateHasExplicitOrderByForLimitToLast } from './query';
 import {
   CollectionReference,
-  doc,
+  doc, DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   Query,
@@ -71,9 +71,9 @@ import { AbstractUserDataWriter } from './user_data_writer';
  * their `set()` or fails due to invalid data originating from a `toFirestore()`
  * call.
  */
-export function applyFirestoreDataConverter<T>(
-  converter: UntypedFirestoreDataConverter<T> | null,
-  value: WithFieldValue<T> | PartialWithFieldValue<T>,
+export function applyFirestoreDataConverter<AppType, DbType extends PublicDocumentData>(
+  converter: UntypedFirestoreDataConverter<AppType, DbType> | null,
+  value: WithFieldValue<AppType> | PartialWithFieldValue<AppType>,
   options?: PublicSetOptions
 ): PublicDocumentData {
   let convertedValue;
@@ -120,10 +120,10 @@ export class LiteUserDataWriter extends AbstractUserDataWriter {
  * @returns A Promise resolved with a `DocumentSnapshot` containing the current
  * document contents.
  */
-export function getDoc<T>(
-  reference: DocumentReference<T>
-): Promise<DocumentSnapshot<T>> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>
+): Promise<DocumentSnapshot<AppType, DbType>> {
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const datastore = getDatastore(reference.firestore);
   const userDataWriter = new LiteUserDataWriter(reference.firestore);
 
@@ -131,7 +131,7 @@ export function getDoc<T>(
     result => {
       hardAssert(result.length === 1, 'Expected a single document result');
       const document = result[0];
-      return new DocumentSnapshot<T>(
+      return new DocumentSnapshot<AppType, DbType>(
         reference.firestore,
         userDataWriter,
         reference._key,
@@ -154,8 +154,8 @@ export function getDoc<T>(
  * @param query - The `Query` to execute.
  * @returns A Promise that will be resolved with the results of the query.
  */
-export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
-  query = cast<Query<T>>(query, Query);
+export function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
+  query = cast<Query<AppType, DbType>>(query, Query);
   validateHasExplicitOrderByForLimitToLast(query._query);
 
   const datastore = getDatastore(query.firestore);
@@ -163,7 +163,7 @@ export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
   return invokeRunQueryRpc(datastore, query._query).then(result => {
     const docs = result.map(
       doc =>
-        new QueryDocumentSnapshot<T>(
+        new QueryDocumentSnapshot<AppType, DbType>(
           query.firestore,
           userDataWriter,
           doc.key,
@@ -179,7 +179,7 @@ export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
       docs.reverse();
     }
 
-    return new QuerySnapshot<T>(query, docs);
+    return new QuerySnapshot<AppType, DbType>(query, docs);
   });
 }
 
@@ -198,9 +198,9 @@ export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: WithFieldValue<T>
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
+  data: WithFieldValue<AppType>
 ): Promise<void>;
 /**
  * Writes to the document referred to by the specified `DocumentReference`. If
@@ -219,17 +219,17 @@ export function setDoc<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: PartialWithFieldValue<T>,
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
+  data: PartialWithFieldValue<AppType>,
   options: SetOptions
 ): Promise<void>;
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: PartialWithFieldValue<T>,
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
+  data: PartialWithFieldValue<AppType>,
   options?: SetOptions
 ): Promise<void> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const convertedValue = applyFirestoreDataConverter(
     reference.converter,
     data,
@@ -269,9 +269,9 @@ export function setDoc<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function updateDoc<T>(
-  reference: DocumentReference<T>,
-  data: UpdateData<T>
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
+  data: UpdateData<DbType>
 ): Promise<void>;
 /**
  * Updates fields in the document referred to by the specified
@@ -294,19 +294,19 @@ export function updateDoc<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function updateDoc(
-  reference: DocumentReference<unknown>,
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
   field: string | FieldPath,
   value: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void>;
-export function updateDoc<T>(
-  reference: DocumentReference<unknown>,
-  fieldOrUpdateData: string | FieldPath | UpdateData<T>,
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>,
+  fieldOrUpdateData: string | FieldPath | UpdateData<DbType>,
   value?: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void> {
-  reference = cast<DocumentReference<unknown>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const dataReader = newUserDataReader(reference.firestore);
 
   // For Compat types, we have to "extract" the underlying types before
@@ -353,10 +353,10 @@ export function updateDoc<T>(
  * @returns A `Promise` resolved once the document has been successfully
  * deleted from the backend.
  */
-export function deleteDoc(
-  reference: DocumentReference<unknown>
+export function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: DocumentReference<AppType, DbType>
 ): Promise<void> {
-  reference = cast<DocumentReference<unknown>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const datastore = getDatastore(reference.firestore);
   return invokeCommitRpc(datastore, [
     new DeleteMutation(reference._key, Precondition.none())
@@ -378,16 +378,16 @@ export function deleteDoc(
  * @returns A `Promise` resolved with a `DocumentReference` pointing to the
  * newly created document after it has been written to the backend.
  */
-export function addDoc<T>(
-  reference: CollectionReference<T>,
-  data: WithFieldValue<T>
-): Promise<DocumentReference<T>> {
-  reference = cast<CollectionReference<T>>(reference, CollectionReference);
+export function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+  reference: CollectionReference<AppType, DbType>,
+  data: WithFieldValue<AppType>
+): Promise<DocumentReference<AppType, DbType>> {
+  reference = cast<CollectionReference<AppType, DbType>>(reference, CollectionReference);
   const docRef = doc(reference);
 
   const convertedValue = applyFirestoreDataConverter(
     reference.converter,
-    data as PartialWithFieldValue<T>
+    data as PartialWithFieldValue<AppType>
   );
 
   const dataReader = newUserDataReader(reference.firestore);
diff --git a/packages/firestore/src/lite-api/snapshot.ts b/packages/firestore/src/lite-api/snapshot.ts
index d00086740bd..c2b353dd088 100644
--- a/packages/firestore/src/lite-api/snapshot.ts
+++ b/packages/firestore/src/lite-api/snapshot.ts
@@ -40,8 +40,8 @@ import {
 import { AbstractUserDataWriter } from './user_data_writer';
 
 /**
- * Converter used by `withConverter()` to transform user objects of type `T`
- * into Firestore data.
+ * Converter used by `withConverter()` to transform user objects of type
+ * `AppType` into Firestore data.
  *
  * Using the converter allows you to specify generic type arguments when
  * storing and retrieving objects from Firestore.
@@ -80,9 +80,11 @@ import { AbstractUserDataWriter } from './user_data_writer';
  */
 export interface FirestoreDataConverter<AppType, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /**
-   * Called by the Firestore SDK to convert a custom model object of type `T`
-   * into a plain Javascript object (suitable for writing directly to the
-   * Firestore database). Used with {@link @firebase/firestore/lite#(setDoc:1)}, {@link @firebase/firestore/lite#(WriteBatch.set:1)}
+   * Called by the Firestore SDK to convert a custom model object of type
+   * `AppType` into a plain Javascript object, `DbType` (suitable for writing
+   * directly to the Firestore database). Used with
+   * {@link @firebase/firestore/lite#(setDoc:1)},
+   * {@link @firebase/firestore/lite#(WriteBatch.set:1)}
    * and {@link @firebase/firestore/lite#(Transaction.set:1)}.
    *
    * The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as
@@ -91,10 +93,13 @@ export interface FirestoreDataConverter<AppType, DbType extends DocumentData = A
   toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 
   /**
-   * Called by the Firestore SDK to convert a custom model object of type `T`
-   * into a plain Javascript object (suitable for writing directly to the
-   * Firestore database). Used with {@link @firebase/firestore/lite#(setDoc:1)}, {@link @firebase/firestore/lite#(WriteBatch.set:1)}
-   * and {@link @firebase/firestore/lite#(Transaction.set:1)} with `merge:true` or `mergeFields`.
+   * Called by the Firestore SDK to convert a custom model object of type
+   * `AppType` into a plain Javascript object, `DbType` (suitable for writing
+   * directly to the Firestore database). Used with
+   * {@link @firebase/firestore/lite#(setDoc:1)},
+   * {@link @firebase/firestore/lite#(WriteBatch.set:1)}
+   * and {@link @firebase/firestore/lite#(Transaction.set:1)} with `merge:true`
+   * or `mergeFields`.
    *
    * The `PartialWithFieldValue<T>` type extends `Partial<T>` to allow
    * FieldValues such as {@link (arrayUnion:1)} to be used as property values.
@@ -107,8 +112,9 @@ export interface FirestoreDataConverter<AppType, DbType extends DocumentData = A
   ): PartialWithFieldValue<DbType>;
 
   /**
-   * Called by the Firestore SDK to convert Firestore data into an object of
-   * type T. You can access your data by calling: `snapshot.data()`.
+   * Called by the Firestore SDK to convert Firestore data `DbType` into an
+   * object of type `AppType`. You can access your data by calling
+   * `snapshot.data()`.
    *
    * @param snapshot - A `QueryDocumentSnapshot` containing your data and
    * metadata.

From 456d3e69007364d149a688005f8ff7a766f227bc Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 11:43:16 -0400
Subject: [PATCH 3/9] finish up lite-api

---
 packages/firestore/src/lite-api/aggregate.ts  |  35 +++-
 .../firestore/src/lite-api/aggregate_types.ts |  10 +-
 packages/firestore/src/lite-api/query.ts      |  63 +++++--
 packages/firestore/src/lite-api/reference.ts  | 167 +++++++++++++++---
 .../firestore/src/lite-api/reference_impl.ts  | 124 +++++++++----
 packages/firestore/src/lite-api/snapshot.ts   |  51 ++++--
 .../firestore/src/lite-api/transaction.ts     |  44 +++--
 .../src/lite-api/user_data_reader.ts          |   7 +-
 .../firestore/src/lite-api/write_batch.ts     |  48 ++---
 .../firestore/test/lite/integration.test.ts   |  67 +++----
 10 files changed, 457 insertions(+), 159 deletions(-)

diff --git a/packages/firestore/src/lite-api/aggregate.ts b/packages/firestore/src/lite-api/aggregate.ts
index fc6de2d045c..129343962c8 100644
--- a/packages/firestore/src/lite-api/aggregate.ts
+++ b/packages/firestore/src/lite-api/aggregate.ts
@@ -32,7 +32,7 @@ import {
 import { getDatastore } from './components';
 import { Firestore } from './database';
 import { FieldPath } from './field_path';
-import {DocumentData, Query, queryEqual} from './reference';
+import { DocumentData, Query, queryEqual } from './reference';
 import { LiteUserDataWriter } from './reference_impl';
 import { fieldPathFromArgument } from './user_data_reader';
 
@@ -50,9 +50,16 @@ import { fieldPathFromArgument } from './user_data_reader';
  * retrieved from `snapshot.data().count`, where `snapshot` is the
  * `AggregateQuerySnapshot` to which the returned Promise resolves.
  */
-export function getCount<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function getCount<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   query: Query<AppType, DbType>
-): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>> {
+): Promise<
+  AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>
+> {
   const countQuerySpec: { count: AggregateField<number> } = {
     count: count()
   };
@@ -87,7 +94,13 @@ export function getCount<AppType = DocumentData, DbType extends DocumentData = A
  * ```
  * @internal TODO (sum/avg) remove when public
  */
-export function getAggregate<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function getAggregate<
+  AggregateSpecType extends AggregateSpec,
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   query: Query<AppType, DbType>,
   aggregateSpec: AggregateSpecType
 ): Promise<AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>> {
@@ -112,13 +125,23 @@ export function getAggregate<AggregateSpecType extends AggregateSpec, AppType =
   );
 }
 
-function convertToAggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+function convertToAggregateQuerySnapshot<
+  AggregateSpecType extends AggregateSpec,
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   firestore: Firestore,
   query: Query<AppType, DbType>,
   aggregateResult: ObjectValue
 ): AggregateQuerySnapshot<AggregateSpecType, AppType, DbType> {
   const userDataWriter = new LiteUserDataWriter(firestore);
-  const querySnapshot = new AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>(query, userDataWriter, aggregateResult);
+  const querySnapshot = new AggregateQuerySnapshot<
+    AggregateSpecType,
+    AppType,
+    DbType
+  >(query, userDataWriter, aggregateResult);
   return querySnapshot;
 }
 
diff --git a/packages/firestore/src/lite-api/aggregate_types.ts b/packages/firestore/src/lite-api/aggregate_types.ts
index d668016efd9..49fa2eaea98 100644
--- a/packages/firestore/src/lite-api/aggregate_types.ts
+++ b/packages/firestore/src/lite-api/aggregate_types.ts
@@ -19,7 +19,7 @@ import { AggregateType } from '../core/aggregate';
 import { ObjectValue } from '../model/object_value';
 import { FieldPath as InternalFieldPath } from '../model/path';
 
-import {DocumentData, Query} from './reference';
+import { DocumentData, Query } from './reference';
 import { AbstractUserDataWriter } from './user_data_writer';
 
 export { AggregateType };
@@ -71,7 +71,13 @@ export type AggregateSpecData<T extends AggregateSpec> = {
 /**
  * The results of executing an aggregation query.
  */
-export class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class AggregateQuerySnapshot<
+  AggregateSpecType extends AggregateSpec,
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /** A type string to uniquely identify instances of this class. */
   readonly type = 'AggregateQuerySnapshot';
 
diff --git a/packages/firestore/src/lite-api/query.ts b/packages/firestore/src/lite-api/query.ts
index 5d4bd9dee97..a59c440a03c 100644
--- a/packages/firestore/src/lite-api/query.ts
+++ b/packages/firestore/src/lite-api/query.ts
@@ -53,7 +53,7 @@ import {
 } from '../util/input_validation';
 
 import { FieldPath } from './field_path';
-import {DocumentData, DocumentReference, Query} from './reference';
+import { DocumentData, DocumentReference, Query } from './reference';
 import { DocumentSnapshot, fieldPathFromArgument } from './snapshot';
 import {
   newUserDataReader,
@@ -95,7 +95,9 @@ export abstract class AppliableConstraint {
    * Takes the provided {@link Query} and returns a copy of the {@link Query} with this
    * {@link AppliableConstraint} applied.
    */
-  abstract _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType>;
+  abstract _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType>;
 }
 
 /**
@@ -114,7 +116,9 @@ export abstract class QueryConstraint extends AppliableConstraint {
    * Takes the provided {@link Query} and returns a copy of the {@link Query} with this
    * {@link AppliableConstraint} applied.
    */
-  abstract _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType>;
+  abstract _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType>;
 }
 
 /**
@@ -131,7 +135,12 @@ export abstract class QueryConstraint extends AppliableConstraint {
  * @throws if any of the provided query constraints cannot be combined with the
  * existing or new constraints.
  */
-export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function query<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   query: Query<AppType, DbType>,
   compositeFilter: QueryCompositeFilterConstraint,
   ...queryConstraints: QueryNonFilterConstraint[]
@@ -147,12 +156,22 @@ export function query<AppType = DocumentData, DbType extends DocumentData = AppT
  * @throws if any of the provided query constraints cannot be combined with the
  * existing or new constraints.
  */
-export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function query<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   query: Query<AppType, DbType>,
   ...queryConstraints: QueryConstraint[]
 ): Query<AppType, DbType>;
 
-export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function query<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   query: Query<AppType, DbType>,
   queryConstraint: QueryCompositeFilterConstraint | QueryConstraint | undefined,
   ...additionalQueryConstraints: Array<
@@ -205,7 +224,9 @@ export class QueryFieldFilterConstraint extends QueryConstraint {
     return new QueryFieldFilterConstraint(_field, _op, _value);
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     const filter = this._parse(query);
     validateNewFieldFilter(query._query, filter);
     return new Query<AppType, DbType>(
@@ -215,7 +236,9 @@ export class QueryFieldFilterConstraint extends QueryConstraint {
     );
   }
 
-  _parse<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): FieldFilter {
+  _parse<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): FieldFilter {
     const reader = newUserDataReader(query.firestore);
     const filter = newQueryFilter(
       query._query,
@@ -295,7 +318,9 @@ export class QueryCompositeFilterConstraint extends AppliableConstraint {
     return new QueryCompositeFilterConstraint(type, _queryConstraints);
   }
 
-  _parse<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Filter {
+  _parse<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Filter {
     const parsedFilters = this._queryConstraints
       .map(queryConstraint => {
         return queryConstraint._parse(query);
@@ -309,7 +334,9 @@ export class QueryCompositeFilterConstraint extends AppliableConstraint {
     return CompositeFilter.create(parsedFilters, this._getOperator());
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     const parsedFilter = this._parse(query);
     if (parsedFilter.getFilters().length === 0) {
       // Return the existing query if not adding any more filters (e.g. an empty
@@ -435,7 +462,9 @@ export class QueryOrderByConstraint extends QueryConstraint {
     return new QueryOrderByConstraint(_field, _direction);
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     const orderBy = newQueryOrderBy(query._query, this._field, this._direction);
     return new Query(
       query.firestore,
@@ -500,7 +529,9 @@ export class QueryLimitConstraint extends QueryConstraint {
     return new QueryLimitConstraint(type, _limit, _limitType);
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     return new Query<AppType, DbType>(
       query.firestore,
       query.converter,
@@ -564,7 +595,9 @@ export class QueryStartAtConstraint extends QueryConstraint {
     return new QueryStartAtConstraint(type, _docOrFields, _inclusive);
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     const bound = newQueryBoundFromDocOrFields(
       query,
       this.type,
@@ -671,7 +704,9 @@ export class QueryEndAtConstraint extends QueryConstraint {
     return new QueryEndAtConstraint(type, _docOrFields, _inclusive);
   }
 
-  _apply<AppType, DbType extends DocumentData>(query: Query<AppType, DbType>): Query<AppType, DbType> {
+  _apply<AppType, DbType extends DocumentData>(
+    query: Query<AppType, DbType>
+  ): Query<AppType, DbType> {
     const bound = newQueryBoundFromDocOrFields(
       query,
       this.type,
diff --git a/packages/firestore/src/lite-api/reference.ts b/packages/firestore/src/lite-api/reference.ts
index d00c2d47bb9..7fd583b65e5 100644
--- a/packages/firestore/src/lite-api/reference.ts
+++ b/packages/firestore/src/lite-api/reference.ts
@@ -110,7 +110,12 @@ export type SetOptions =
  * and can be used to write, read, or listen to the location. The document at
  * the referenced location may or may not exist.
  */
-export class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class DocumentReference<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /** The type of this Firestore reference. */
   readonly type = 'document';
 
@@ -172,7 +177,14 @@ export class DocumentReference<AppType = DocumentData, DbType extends DocumentDa
    * @param converter - Converts objects to and from Firestore.
    * @returns A `DocumentReference<U>` that uses the provided converter.
    */
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
+    converter: FirestoreDataConverter<NewAppType, NewDbType>
+  ): DocumentReference<NewAppType, NewDbType>;
   /**
    * Removes the current converter.
    *
@@ -180,10 +192,19 @@ export class DocumentReference<AppType = DocumentData, DbType extends DocumentDa
    * @returns A `DocumentReference<DocumentData>` that does not use a converter.
    */
   withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
     converter: FirestoreDataConverter<NewAppType, NewDbType> | null
   ): DocumentReference<NewAppType, NewDbType> {
-    return new DocumentReference<NewAppType, NewDbType>(this.firestore, converter, this._key);
+    return new DocumentReference<NewAppType, NewDbType>(
+      this.firestore,
+      converter,
+      this._key
+    );
   }
 }
 
@@ -191,7 +212,12 @@ export class DocumentReference<AppType = DocumentData, DbType extends DocumentDa
  * A `Query` refers to a query which you can read or listen to. You can also
  * construct refined `Query` objects by adding filters and ordering.
  */
-export class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class Query<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /** The type of this Firestore reference. */
   readonly type: 'query' | 'collection' = 'query';
 
@@ -231,9 +257,27 @@ export class Query<AppType = DocumentData, DbType extends DocumentData = AppType
    * @param converter - Converts objects to and from Firestore.
    * @returns A `Query<U>` that uses the provided converter.
    */
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType> | null): Query<NewAppType, NewDbType> {
-    return new Query<NewAppType, NewDbType>(this.firestore, converter, this._query);
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
+    converter: FirestoreDataConverter<NewAppType, NewDbType>
+  ): Query<NewAppType, NewDbType>;
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
+    converter: FirestoreDataConverter<NewAppType, NewDbType> | null
+  ): Query<NewAppType, NewDbType> {
+    return new Query<NewAppType, NewDbType>(
+      this.firestore,
+      converter,
+      this._query
+    );
   }
 }
 
@@ -241,7 +285,12 @@ export class Query<AppType = DocumentData, DbType extends DocumentData = AppType
  * A `CollectionReference` object can be used for adding documents, getting
  * document references, and querying for documents (using {@link (query:1)}).
  */
-export class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> {
+export class CollectionReference<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> extends Query<AppType, DbType> {
   /** The type of this Firestore reference. */
   readonly type = 'collection';
 
@@ -293,7 +342,12 @@ export class CollectionReference<AppType = DocumentData, DbType extends Document
    * @param converter - Converts objects to and from Firestore.
    * @returns A `CollectionReference<U>` that uses the provided converter.
    */
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
     converter: FirestoreDataConverter<NewAppType, NewDbType>
   ): CollectionReference<NewAppType, NewDbType>;
   /**
@@ -303,9 +357,22 @@ export class CollectionReference<AppType = DocumentData, DbType extends Document
    * @returns A `CollectionReference<DocumentData>` that does not use a
    * converter.
    */
-  withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
-  withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType> | null): CollectionReference<NewAppType, NewDbType> {
-    return new CollectionReference<NewAppType, NewDbType>(this.firestore, converter, this._path);
+  withConverter(
+    converter: null
+  ): CollectionReference<DocumentData, DocumentData>;
+  withConverter<
+    NewAppType = DocumentData,
+    NewDbType extends DocumentData = NewAppType extends DocumentData
+      ? NewAppType
+      : DocumentData
+  >(
+    converter: FirestoreDataConverter<NewAppType, NewDbType> | null
+  ): CollectionReference<NewAppType, NewDbType> {
+    return new CollectionReference<NewAppType, NewDbType>(
+      this.firestore,
+      converter,
+      this._path
+    );
   }
 }
 
@@ -338,7 +405,12 @@ export function collection(
  * to a collection.
  * @returns The `CollectionReference` instance.
  */
-export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function collection<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: CollectionReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
@@ -355,13 +427,26 @@ export function collection<AppType = DocumentData, DbType extends DocumentData =
  * to a collection.
  * @returns The `CollectionReference` instance.
  */
-export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function collection<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
 ): CollectionReference<DocumentData, DocumentData>;
-export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
-  parent: Firestore | DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>,
+export function collection<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  parent:
+    | Firestore
+    | DocumentReference<AppType, DbType>
+    | CollectionReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
 ): CollectionReference<DocumentData, DocumentData> {
@@ -463,7 +548,12 @@ export function doc(
  * a document.
  * @returns The `DocumentReference` instance.
  */
-export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function doc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: CollectionReference<AppType, DbType>,
   path?: string,
   ...pathSegments: string[]
@@ -480,13 +570,26 @@ export function doc<AppType = DocumentData, DbType extends DocumentData = AppTyp
  * a document.
  * @returns The `DocumentReference` instance.
  */
-export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function doc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   path: string,
   ...pathSegments: string[]
 ): DocumentReference<DocumentData, DocumentData>;
-export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
-  parent: Firestore | CollectionReference<AppType, DbType> | DocumentReference<AppType, DbType>,
+export function doc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  parent:
+    | Firestore
+    | CollectionReference<AppType, DbType>
+    | DocumentReference<AppType, DbType>,
   path?: string,
   ...pathSegments: string[]
 ): DocumentReference<AppType, DbType> {
@@ -538,9 +641,18 @@ export function doc<AppType = DocumentData, DbType extends DocumentData = AppTyp
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
-  left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>,
-  right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>
+export function refEqual<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  left:
+    | DocumentReference<AppType, DbType>
+    | CollectionReference<AppType, DbType>,
+  right:
+    | DocumentReference<AppType, DbType>
+    | CollectionReference<AppType, DbType>
 ): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
@@ -568,7 +680,12 @@ export function refEqual<AppType = DocumentData, DbType extends DocumentData = A
  * @returns true if the references point to the same location in the same
  * Firestore database.
  */
-export function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean {
+export function queryEqual<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
 
diff --git a/packages/firestore/src/lite-api/reference_impl.ts b/packages/firestore/src/lite-api/reference_impl.ts
index 7f20b93afa5..63dfb97d720 100644
--- a/packages/firestore/src/lite-api/reference_impl.ts
+++ b/packages/firestore/src/lite-api/reference_impl.ts
@@ -39,7 +39,8 @@ import { FieldPath } from './field_path';
 import { validateHasExplicitOrderByForLimitToLast } from './query';
 import {
   CollectionReference,
-  doc, DocumentData,
+  doc,
+  DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   Query,
@@ -71,25 +72,21 @@ import { AbstractUserDataWriter } from './user_data_writer';
  * their `set()` or fails due to invalid data originating from a `toFirestore()`
  * call.
  */
-export function applyFirestoreDataConverter<AppType, DbType extends PublicDocumentData>(
+export function applyFirestoreDataConverter<
+  AppType,
+  DbType extends PublicDocumentData
+>(
   converter: UntypedFirestoreDataConverter<AppType, DbType> | null,
   value: WithFieldValue<AppType> | PartialWithFieldValue<AppType>,
   options?: PublicSetOptions
 ): PublicDocumentData {
-  let convertedValue;
-  if (converter) {
-    if (options && (options.merge || options.mergeFields)) {
-      // Cast to `any` in order to satisfy the union type constraint on
-      // toFirestore().
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      convertedValue = (converter as any).toFirestore(value, options);
-    } else {
-      convertedValue = converter.toFirestore(value as WithFieldValue<T>);
-    }
-  } else {
-    convertedValue = value as PublicDocumentData;
+  if (!converter) {
+    return value as PublicDocumentData;
+  }
+  if (options && (options.merge || options.mergeFields)) {
+    return converter.toFirestore(value, options);
   }
-  return convertedValue;
+  return converter.toFirestore(value as WithFieldValue<AppType>);
 }
 
 export class LiteUserDataWriter extends AbstractUserDataWriter {
@@ -120,10 +117,18 @@ export class LiteUserDataWriter extends AbstractUserDataWriter {
  * @returns A Promise resolved with a `DocumentSnapshot` containing the current
  * document contents.
  */
-export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function getDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>
 ): Promise<DocumentSnapshot<AppType, DbType>> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const datastore = getDatastore(reference.firestore);
   const userDataWriter = new LiteUserDataWriter(reference.firestore);
 
@@ -154,7 +159,12 @@ export function getDoc<AppType = DocumentData, DbType extends DocumentData = App
  * @param query - The `Query` to execute.
  * @returns A Promise that will be resolved with the results of the query.
  */
-export function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
+export function getDocs<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
   query = cast<Query<AppType, DbType>>(query, Query);
   validateHasExplicitOrderByForLimitToLast(query._query);
 
@@ -198,7 +208,12 @@ export function getDocs<AppType = DocumentData, DbType extends DocumentData = Ap
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   data: WithFieldValue<AppType>
 ): Promise<void>;
@@ -219,17 +234,30 @@ export function setDoc<AppType = DocumentData, DbType extends DocumentData = App
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   data: PartialWithFieldValue<AppType>,
   options: SetOptions
 ): Promise<void>;
-export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   data: PartialWithFieldValue<AppType>,
   options?: SetOptions
 ): Promise<void> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const convertedValue = applyFirestoreDataConverter(
     reference.converter,
     data,
@@ -269,7 +297,12 @@ export function setDoc<AppType = DocumentData, DbType extends DocumentData = App
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   data: UpdateData<DbType>
 ): Promise<void>;
@@ -294,19 +327,32 @@ export function updateDoc<AppType = DocumentData, DbType extends DocumentData =
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend.
  */
-export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   field: string | FieldPath,
   value: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void>;
-export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: DocumentReference<AppType, DbType>,
   fieldOrUpdateData: string | FieldPath | UpdateData<DbType>,
   value?: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const dataReader = newUserDataReader(reference.firestore);
 
   // For Compat types, we have to "extract" the underlying types before
@@ -353,10 +399,16 @@ export function updateDoc<AppType = DocumentData, DbType extends DocumentData =
  * @returns A `Promise` resolved once the document has been successfully
  * deleted from the backend.
  */
-export function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
-  reference: DocumentReference<AppType, DbType>
-): Promise<void> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+export function deleteDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(reference: DocumentReference<AppType, DbType>): Promise<void> {
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const datastore = getDatastore(reference.firestore);
   return invokeCommitRpc(datastore, [
     new DeleteMutation(reference._key, Precondition.none())
@@ -378,11 +430,19 @@ export function deleteDoc<AppType = DocumentData, DbType extends DocumentData =
  * @returns A `Promise` resolved with a `DocumentReference` pointing to the
  * newly created document after it has been written to the backend.
  */
-export function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(
+export function addDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
   reference: CollectionReference<AppType, DbType>,
   data: WithFieldValue<AppType>
 ): Promise<DocumentReference<AppType, DbType>> {
-  reference = cast<CollectionReference<AppType, DbType>>(reference, CollectionReference);
+  reference = cast<CollectionReference<AppType, DbType>>(
+    reference,
+    CollectionReference
+  );
   const docRef = doc(reference);
 
   const convertedValue = applyFirestoreDataConverter(
diff --git a/packages/firestore/src/lite-api/snapshot.ts b/packages/firestore/src/lite-api/snapshot.ts
index c2b353dd088..7e95fec8c91 100644
--- a/packages/firestore/src/lite-api/snapshot.ts
+++ b/packages/firestore/src/lite-api/snapshot.ts
@@ -78,7 +78,12 @@ import { AbstractUserDataWriter } from './user_data_writer';
  * }
  * ```
  */
-export interface FirestoreDataConverter<AppType, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export interface FirestoreDataConverter<
+  AppType,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /**
    * Called by the Firestore SDK to convert a custom model object of type
    * `AppType` into a plain Javascript object, `DbType` (suitable for writing
@@ -131,7 +136,12 @@ export interface FirestoreDataConverter<AppType, DbType extends DocumentData = A
  * access will return 'undefined'. You can use the `exists()` method to
  * explicitly verify a document's existence.
  */
-export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class DocumentSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   // Note: This class is stripped down version of the DocumentSnapshot in
   // the legacy SDK. The changes are:
   // - No support for SnapshotMetadata.
@@ -193,7 +203,9 @@ export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentDat
       );
       return this._converter.fromFirestore(snapshot);
     } else {
-      return this._userDataWriter.convertValue(this._document.data.value) as AppType;
+      return this._userDataWriter.convertValue(
+        this._document.data.value
+      ) as AppType;
     }
   }
 
@@ -232,7 +244,12 @@ export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentDat
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
+export class QueryDocumentSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> extends DocumentSnapshot<AppType, DbType> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *
@@ -251,7 +268,12 @@ export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends Docume
  * number of documents can be determined via the `empty` and `size`
  * properties.
  */
-export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class QuerySnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /**
    * The query on which you called {@link getDocs} in order to get this
    * `QuerySnapshot`.
@@ -260,14 +282,14 @@ export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData =
 
   /** @hideconstructor */
   constructor(
-    _query: Query<T>,
-    readonly _docs: Array<QueryDocumentSnapshot<T>>
+    _query: Query<AppType, DbType>,
+    readonly _docs: Array<QueryDocumentSnapshot<AppType, DbType>>
   ) {
     this.query = _query;
   }
 
   /** An array of all the documents in the `QuerySnapshot`. */
-  get docs(): Array<QueryDocumentSnapshot<T>> {
+  get docs(): Array<QueryDocumentSnapshot<AppType, DbType>> {
     return [...this._docs];
   }
 
@@ -289,7 +311,7 @@ export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData =
    * @param thisArg - The `this` binding for the callback.
    */
   forEach(
-    callback: (result: QueryDocumentSnapshot<T>) => void,
+    callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void,
     thisArg?: unknown
   ): void {
     this._docs.forEach(callback, thisArg);
@@ -303,9 +325,14 @@ export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData =
  * @param right - A snapshot to compare.
  * @returns true if the snapshots are equal.
  */
-export function snapshotEqual<T>(
-  left: DocumentSnapshot<T> | QuerySnapshot<T>,
-  right: DocumentSnapshot<T> | QuerySnapshot<T>
+export function snapshotEqual<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>,
+  right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>
 ): boolean {
   left = getModularInstance(left);
   right = getModularInstance(right);
diff --git a/packages/firestore/src/lite-api/transaction.ts b/packages/firestore/src/lite-api/transaction.ts
index a1724ee0960..17b55a98e13 100644
--- a/packages/firestore/src/lite-api/transaction.ts
+++ b/packages/firestore/src/lite-api/transaction.ts
@@ -87,7 +87,9 @@ export class Transaction {
    * @param documentRef - A reference to the document to be read.
    * @returns A `DocumentSnapshot` with the read data.
    */
-  get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
+  get<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>
+  ): Promise<DocumentSnapshot<AppType, DbType>> {
     const ref = validateReference(documentRef, this._firestore);
     const userDataWriter = new LiteUserDataWriter(this._firestore);
     return this._transaction.lookup([ref._key]).then(docs => {
@@ -96,7 +98,7 @@ export class Transaction {
       }
       const doc = docs[0];
       if (doc.isFoundDocument()) {
-        return new DocumentSnapshot(
+        return new DocumentSnapshot<AppType, DbType>(
           this._firestore,
           userDataWriter,
           doc.key,
@@ -104,7 +106,7 @@ export class Transaction {
           ref.converter
         );
       } else if (doc.isNoDocument()) {
-        return new DocumentSnapshot(
+        return new DocumentSnapshot<AppType, DbType>(
           this._firestore,
           userDataWriter,
           ref._key,
@@ -128,7 +130,10 @@ export class Transaction {
    * @throws Error - If the provided input is not a valid Firestore document.
    * @returns This `Transaction` instance. Used for chaining method calls.
    */
-  set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): this;
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: WithFieldValue<AppType>
+  ): this;
   /**
    * Writes to the document referred to by the provided {@link
    * DocumentReference}. If the document does not exist yet, it will be created.
@@ -141,14 +146,14 @@ export class Transaction {
    * @throws Error - If the provided input is not a valid Firestore document.
    * @returns This `Transaction` instance. Used for chaining method calls.
    */
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: PartialWithFieldValue<T>,
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: PartialWithFieldValue<AppType>,
     options: SetOptions
   ): this;
-  set<T>(
-    documentRef: DocumentReference<T>,
-    value: PartialWithFieldValue<T>,
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    value: PartialWithFieldValue<AppType>,
     options?: SetOptions
   ): this {
     const ref = validateReference(documentRef, this._firestore);
@@ -181,7 +186,10 @@ export class Transaction {
    * @throws Error - If the provided input is not valid Firestore data.
    * @returns This `Transaction` instance. Used for chaining method calls.
    */
-  update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): this;
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: UpdateData<DbType>
+  ): this;
   /**
    * Updates fields in the document referred to by the provided {@link
    * DocumentReference}. The update will fail if applied to a document that does
@@ -197,15 +205,15 @@ export class Transaction {
    * @throws Error - If the provided input is not valid Firestore data.
    * @returns This `Transaction` instance. Used for chaining method calls.
    */
-  update(
-    documentRef: DocumentReference<unknown>,
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
     field: string | FieldPath,
     value: unknown,
     ...moreFieldsAndValues: unknown[]
   ): this;
-  update<T>(
-    documentRef: DocumentReference<T>,
-    fieldOrUpdateData: string | FieldPath | UpdateData<T>,
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    fieldOrUpdateData: string | FieldPath | UpdateData<DbType>,
     value?: unknown,
     ...moreFieldsAndValues: unknown[]
   ): this {
@@ -247,7 +255,9 @@ export class Transaction {
    * @param documentRef - A reference to the document to be deleted.
    * @returns This `Transaction` instance. Used for chaining method calls.
    */
-  delete(documentRef: DocumentReference<unknown>): this {
+  delete<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>
+  ): this {
     const ref = validateReference(documentRef, this._firestore);
     this._transaction.delete(ref._key);
     return this;
diff --git a/packages/firestore/src/lite-api/user_data_reader.ts b/packages/firestore/src/lite-api/user_data_reader.ts
index d384c6e3a79..6f2fcd730f3 100644
--- a/packages/firestore/src/lite-api/user_data_reader.ts
+++ b/packages/firestore/src/lite-api/user_data_reader.ts
@@ -76,7 +76,12 @@ const RESERVED_FIELD_REGEX = /^__.*__$/;
  * An untyped Firestore Data Converter interface that is shared between the
  * lite, firestore-exp and classic SDK.
  */
-export interface UntypedFirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData> {
+export interface UntypedFirestoreDataConverter<
+  AppType,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
   toFirestore(
     modelObject: PartialWithFieldValue<AppType>,
diff --git a/packages/firestore/src/lite-api/write_batch.ts b/packages/firestore/src/lite-api/write_batch.ts
index e626646f3f7..686395b0c92 100644
--- a/packages/firestore/src/lite-api/write_batch.ts
+++ b/packages/firestore/src/lite-api/write_batch.ts
@@ -26,6 +26,7 @@ import { getDatastore } from './components';
 import { Firestore } from './database';
 import { FieldPath } from './field_path';
 import {
+  DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   SetOptions,
@@ -73,9 +74,9 @@ export class WriteBatch {
    * @param data - An object of the fields and values for the document.
    * @returns This `WriteBatch` instance. Used for chaining method calls.
    */
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: WithFieldValue<T>
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: WithFieldValue<AppType>
   ): WriteBatch;
   /**
    * Writes to the document referred to by the provided {@link
@@ -89,14 +90,14 @@ export class WriteBatch {
    * @throws Error - If the provided input is not a valid Firestore document.
    * @returns This `WriteBatch` instance. Used for chaining method calls.
    */
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: PartialWithFieldValue<T>,
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: PartialWithFieldValue<AppType>,
     options: SetOptions
   ): WriteBatch;
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: WithFieldValue<T> | PartialWithFieldValue<T>,
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: WithFieldValue<AppType> | PartialWithFieldValue<AppType>,
     options?: SetOptions
   ): WriteBatch {
     this._verifyNotCommitted();
@@ -131,7 +132,10 @@ export class WriteBatch {
    * @throws Error - If the provided input is not valid Firestore data.
    * @returns This `WriteBatch` instance. Used for chaining method calls.
    */
-  update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): WriteBatch;
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: UpdateData<DbType>
+  ): WriteBatch;
   /**
    * Updates fields in the document referred to by this {@link
    * DocumentReference}. The update will fail if applied to a document that does
@@ -147,15 +151,15 @@ export class WriteBatch {
    * @throws Error - If the provided input is not valid Firestore data.
    * @returns This `WriteBatch` instance. Used for chaining method calls.
    */
-  update(
-    documentRef: DocumentReference<unknown>,
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
     field: string | FieldPath,
     value: unknown,
     ...moreFieldsAndValues: unknown[]
   ): WriteBatch;
-  update<T>(
-    documentRef: DocumentReference<T>,
-    fieldOrUpdateData: string | FieldPath | UpdateData<T>,
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    fieldOrUpdateData: string | FieldPath | UpdateData<DbType>,
     value?: unknown,
     ...moreFieldsAndValues: unknown[]
   ): WriteBatch {
@@ -200,7 +204,9 @@ export class WriteBatch {
    * @param documentRef - A reference to the document to be deleted.
    * @returns This `WriteBatch` instance. Used for chaining method calls.
    */
-  delete(documentRef: DocumentReference<unknown>): WriteBatch {
+  delete<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>
+  ): WriteBatch {
     this._verifyNotCommitted();
     const ref = validateReference(documentRef, this._firestore);
     this._mutations = this._mutations.concat(
@@ -242,10 +248,12 @@ export class WriteBatch {
   }
 }
 
-export function validateReference<T>(
-  documentRef: DocumentReference<T> | Compat<DocumentReference<T>>,
+export function validateReference<AppType, DbType extends DocumentData>(
+  documentRef:
+    | DocumentReference<AppType, DbType>
+    | Compat<DocumentReference<AppType, DbType>>,
   firestore: Firestore
-): DocumentReference<T> {
+): DocumentReference<AppType, DbType> {
   documentRef = getModularInstance(documentRef);
 
   if (documentRef.firestore !== firestore) {
@@ -254,7 +262,7 @@ export function validateReference<T>(
       'Provided document reference is from a different Firestore instance.'
     );
   } else {
-    return documentRef as DocumentReference<T>;
+    return documentRef as DocumentReference<AppType, DbType>;
   }
 }
 
diff --git a/packages/firestore/test/lite/integration.test.ts b/packages/firestore/test/lite/integration.test.ts
index 0c8515f038c..52eee3ec5d6 100644
--- a/packages/firestore/test/lite/integration.test.ts
+++ b/packages/firestore/test/lite/integration.test.ts
@@ -79,6 +79,7 @@ import {
 } from '../../src/lite-api/reference_impl';
 import {
   snapshotEqual,
+  FirestoreDataConverter,
   QuerySnapshot,
   QueryDocumentSnapshot
 } from '../../src/lite-api/snapshot';
@@ -428,26 +429,28 @@ describe('getDoc()', () => {
  * DocumentReference-based mutation API.
  */
 interface MutationTester {
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: WithFieldValue<T>
-  ): Promise<void>;
-  set<T>(
-    documentRef: DocumentReference<T>,
-    data: PartialWithFieldValue<T>,
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: PartialWithFieldValue<AppType>,
     options: SetOptions
   ): Promise<void>;
-  update<T>(
-    documentRef: DocumentReference<T>,
-    data: UpdateData<T>
+  set<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: WithFieldValue<AppType>
+  ): Promise<void>;
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
+    data: UpdateData<DbType>
   ): Promise<void>;
-  update(
-    documentRef: DocumentReference<unknown>,
+  update<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>,
     field: string | FieldPath,
     value: unknown,
     ...moreFieldsAndValues: unknown[]
   ): Promise<void>;
-  delete(documentRef: DocumentReference<unknown>): Promise<void>;
+  delete<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>
+  ): Promise<void>;
 }
 
 genericMutationTests({
@@ -458,15 +461,17 @@ genericMutationTests({
 
 describe('WriteBatch', () => {
   class WriteBatchTester implements MutationTester {
-    delete(ref: DocumentReference<unknown>): Promise<void> {
+    delete<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>
+    ): Promise<void> {
       const batch = writeBatch(ref.firestore);
       batch.delete(ref);
       return batch.commit();
     }
 
-    set<T>(
-      ref: DocumentReference<T>,
-      data: PartialWithFieldValue<T>,
+    set<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>,
+      data: PartialWithFieldValue<AppType>,
       options?: SetOptions
     ): Promise<void> {
       const batch = writeBatch(ref.firestore);
@@ -476,9 +481,9 @@ describe('WriteBatch', () => {
       return batch.commit();
     }
 
-    update<T>(
-      ref: DocumentReference<T>,
-      dataOrField: UpdateData<T> | string | FieldPath,
+    update<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>,
+      dataOrField: UpdateData<DbType> | string | FieldPath,
       value?: unknown,
       ...moreFieldsAndValues: unknown[]
     ): Promise<void> {
@@ -521,29 +526,31 @@ describe('WriteBatch', () => {
 
 describe('Transaction', () => {
   class TransactionTester implements MutationTester {
-    delete(ref: DocumentReference<unknown>): Promise<void> {
+    delete<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>
+    ): Promise<void> {
       return runTransaction(ref.firestore, async transaction => {
         transaction.delete(ref);
       });
     }
 
-    set<T>(
-      ref: DocumentReference<T>,
-      data: PartialWithFieldValue<T>,
+    set<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>,
+      data: PartialWithFieldValue<AppType>,
       options?: SetOptions
     ): Promise<void> {
       return runTransaction(ref.firestore, async transaction => {
         if (options) {
           transaction.set(ref, data, options);
         } else {
-          transaction.set(ref, data as WithFieldValue<T>);
+          transaction.set(ref, data as WithFieldValue<AppType>);
         }
       });
     }
 
-    update<T>(
-      ref: DocumentReference<T>,
-      dataOrField: UpdateData<T> | string | FieldPath,
+    update<AppType, DbType extends DocumentData>(
+      ref: DocumentReference<AppType, DbType>,
+      dataOrField: UpdateData<DbType> | string | FieldPath,
       value?: unknown,
       ...moreFieldsAndValues: unknown[]
     ): Promise<void> {
@@ -556,7 +563,7 @@ describe('Transaction', () => {
             ...moreFieldsAndValues
           );
         } else {
-          transaction.update(ref, dataOrField as UpdateData<T>);
+          transaction.update(ref, dataOrField as UpdateData<DbType>);
         }
       });
     }
@@ -1385,7 +1392,7 @@ describe('withConverter() support', () => {
       ) {}
     }
 
-    const testConverter = {
+    const testConverter: FirestoreDataConverter<TestObject> = {
       toFirestore(testObj: WithFieldValue<TestObject>) {
         return { ...testObj };
       },

From 8d5257f1810323271bbab922a4215ac64e9d7d60 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 11:49:39 -0400
Subject: [PATCH 4/9] cleanup:

---
 packages/firestore/src/lite-api/aggregate.ts      | 8 +++++---
 packages/firestore/src/lite-api/reference_impl.ts | 4 ++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/packages/firestore/src/lite-api/aggregate.ts b/packages/firestore/src/lite-api/aggregate.ts
index 129343962c8..13981e7246b 100644
--- a/packages/firestore/src/lite-api/aggregate.ts
+++ b/packages/firestore/src/lite-api/aggregate.ts
@@ -208,9 +208,11 @@ export function aggregateFieldEqual(
  * @returns `true` if the objects are "equal", as defined above, or `false`
  * otherwise.
  */
-export function aggregateQuerySnapshotEqual<T extends AggregateSpec>(
-  left: AggregateQuerySnapshot<T>,
-  right: AggregateQuerySnapshot<T>
+export function aggregateQuerySnapshotEqual<
+  AggregateSpecType extends AggregateSpec
+>(
+  left: AggregateQuerySnapshot<AggregateSpecType>,
+  right: AggregateQuerySnapshot<AggregateSpecType>
 ): boolean {
   return (
     queryEqual(left.query, right.query) && deepEqual(left.data(), right.data())
diff --git a/packages/firestore/src/lite-api/reference_impl.ts b/packages/firestore/src/lite-api/reference_impl.ts
index 63dfb97d720..7c8ceb93a24 100644
--- a/packages/firestore/src/lite-api/reference_impl.ts
+++ b/packages/firestore/src/lite-api/reference_impl.ts
@@ -64,8 +64,8 @@ import {
 import { AbstractUserDataWriter } from './user_data_writer';
 
 /**
- * Converts custom model object of type T into `DocumentData` by applying the
- * converter if it exists.
+ * Converts custom model object of type `AppType` into `DocumentData` by
+ * applying the converter if it exists.
  *
  * This function is used when converting user objects to `DocumentData`
  * because we want to provide the user with a more specific error message if

From f921d2511e3a99674a7ad5c78e9d9fbf231c9c64 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 12:43:59 -0400
Subject: [PATCH 5/9] do normal api

---
 packages/firestore/src/api/aggregate.ts      |  20 +-
 packages/firestore/src/api/reference_impl.ts | 257 +++++++++++++------
 packages/firestore/src/api/snapshot.ts       |  76 +++---
 packages/firestore/src/api/transaction.ts    |   6 +-
 4 files changed, 222 insertions(+), 137 deletions(-)

diff --git a/packages/firestore/src/api/aggregate.ts b/packages/firestore/src/api/aggregate.ts
index 3ced0c8b292..74d1c68bbfb 100644
--- a/packages/firestore/src/api/aggregate.ts
+++ b/packages/firestore/src/api/aggregate.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import { AggregateField, AggregateSpec, Query } from '../api';
+import {AggregateField, AggregateSpec, DocumentData, Query} from '../api';
 import { AggregateImpl } from '../core/aggregate';
 import { firestoreClientRunAggregateQuery } from '../core/firestore_client';
 import { count } from '../lite-api/aggregate';
@@ -57,9 +57,7 @@ export {
  * retrieved from `snapshot.data().count`, where `snapshot` is the
  * `AggregateQuerySnapshot` to which the returned Promise resolves.
  */
-export function getCountFromServer(
-  query: Query<unknown>
-): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }>> {
+export function getCountFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>> {
   const countQuerySpec: { count: AggregateField<number> } = {
     count: count()
   };
@@ -101,10 +99,7 @@ export function getCountFromServer(
  * ```
  * @internal TODO (sum/avg) remove when public
  */
-export function getAggregateFromServer<T extends AggregateSpec>(
-  query: Query<unknown>,
-  aggregateSpec: T
-): Promise<AggregateQuerySnapshot<T>> {
+export function getAggregateFromServer<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, aggregateSpec: AggregateSpecType): Promise<AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>> {
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -133,16 +128,11 @@ export function getAggregateFromServer<T extends AggregateSpec>(
  * @param aggregateResult Core aggregation result
  * @internal
  */
-function convertToAggregateQuerySnapshot<T extends AggregateSpec>(
-  firestore: Firestore,
-  query: Query<unknown>,
-  aggregateResult: ObjectValue
-): AggregateQuerySnapshot<T> {
+function convertToAggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType, DbType extends DocumentData>(firestore: Firestore, query: Query<AppType, DbType>, aggregateResult: ObjectValue): AggregateQuerySnapshot<AggregateSpecType, AppType, DbType> {
   const userDataWriter = new ExpUserDataWriter(firestore);
-  const querySnapshot = new AggregateQuerySnapshot<T>(
+  return new AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>(
     query,
     userDataWriter,
     aggregateResult
   );
-  return querySnapshot;
 }
diff --git a/packages/firestore/src/api/reference_impl.ts b/packages/firestore/src/api/reference_impl.ts
index eabd0fb0021..25316acb056 100644
--- a/packages/firestore/src/api/reference_impl.ts
+++ b/packages/firestore/src/api/reference_impl.ts
@@ -40,7 +40,7 @@ import { FieldPath } from '../lite-api/field_path';
 import { validateHasExplicitOrderByForLimitToLast } from '../lite-api/query';
 import {
   CollectionReference,
-  doc,
+  doc, DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   Query,
@@ -91,10 +91,8 @@ export interface SnapshotListenOptions {
  * @returns A Promise resolved with a `DocumentSnapshot` containing the
  * current document contents.
  */
-export function getDoc<T>(
-  reference: DocumentReference<T>
-): Promise<DocumentSnapshot<T>> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -126,10 +124,15 @@ export class ExpUserDataWriter extends AbstractUserDataWriter {
  * @returns A `Promise` resolved with a `DocumentSnapshot` containing the
  * current document contents.
  */
-export function getDocFromCache<T>(
-  reference: DocumentReference<T>
-): Promise<DocumentSnapshot<T>> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+export function getDocFromCache<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>
+): Promise<DocumentSnapshot<AppType, DbType>> {
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
   const userDataWriter = new ExpUserDataWriter(firestore);
@@ -157,10 +160,15 @@ export function getDocFromCache<T>(
  * @returns A `Promise` resolved with a `DocumentSnapshot` containing the
  * current document contents.
  */
-export function getDocFromServer<T>(
-  reference: DocumentReference<T>
-): Promise<DocumentSnapshot<T>> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+export function getDocFromServer<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>
+): Promise<DocumentSnapshot<AppType, DbType>> {
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -179,8 +187,13 @@ export function getDocFromServer<T>(
  *
  * @returns A `Promise` that will be resolved with the results of the query.
  */
-export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
-  query = cast<Query<T>>(query, Query);
+export function getDocs<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
+  query = cast<Query<AppType, DbType>>(query, Query);
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
   const userDataWriter = new ExpUserDataWriter(firestore);
@@ -201,10 +214,15 @@ export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>> {
  *
  * @returns A `Promise` that will be resolved with the results of the query.
  */
-export function getDocsFromCache<T>(
-  query: Query<T>
-): Promise<QuerySnapshot<T>> {
-  query = cast<Query<T>>(query, Query);
+export function getDocsFromCache<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>
+): Promise<QuerySnapshot<AppType, DbType>> {
+  query = cast<Query<AppType, DbType>>(query, Query);
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
   const userDataWriter = new ExpUserDataWriter(firestore);
@@ -220,10 +238,15 @@ export function getDocsFromCache<T>(
  *
  * @returns A `Promise` that will be resolved with the results of the query.
  */
-export function getDocsFromServer<T>(
-  query: Query<T>
-): Promise<QuerySnapshot<T>> {
-  query = cast<Query<T>>(query, Query);
+export function getDocsFromServer<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>
+): Promise<QuerySnapshot<AppType, DbType>> {
+  query = cast<Query<AppType, DbType>>(query, Query);
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
   const userDataWriter = new ExpUserDataWriter(firestore);
@@ -244,9 +267,14 @@ export function getDocsFromServer<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend (note that it won't resolve while you're offline).
  */
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: WithFieldValue<T>
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  data: WithFieldValue<AppType>
 ): Promise<void>;
 /**
  * Writes to the document referred to by the specified `DocumentReference`. If
@@ -259,22 +287,32 @@ export function setDoc<T>(
  * @returns A Promise resolved once the data has been successfully written
  * to the backend (note that it won't resolve while you're offline).
  */
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: PartialWithFieldValue<T>,
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  data: PartialWithFieldValue<AppType>,
   options: SetOptions
 ): Promise<void>;
-export function setDoc<T>(
-  reference: DocumentReference<T>,
-  data: PartialWithFieldValue<T>,
+export function setDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  data: PartialWithFieldValue<AppType>,
   options?: SetOptions
 ): Promise<void> {
-  reference = cast<DocumentReference<T>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const firestore = cast(reference.firestore, Firestore);
 
   const convertedValue = applyFirestoreDataConverter(
     reference.converter,
-    data as WithFieldValue<T>,
+    data as WithFieldValue<AppType>,
     options
   );
   const dataReader = newUserDataReader(firestore);
@@ -303,9 +341,14 @@ export function setDoc<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend (note that it won't resolve while you're offline).
  */
-export function updateDoc<T>(
-  reference: DocumentReference<T>,
-  data: UpdateData<T>
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  data: UpdateData<DbType>
 ): Promise<void>;
 /**
  * Updates fields in the document referred to by the specified
@@ -322,19 +365,29 @@ export function updateDoc<T>(
  * @returns A `Promise` resolved once the data has been successfully written
  * to the backend (note that it won't resolve while you're offline).
  */
-export function updateDoc(
-  reference: DocumentReference<unknown>,
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
   field: string | FieldPath,
   value: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void>;
-export function updateDoc<T>(
-  reference: DocumentReference<unknown>,
-  fieldOrUpdateData: string | FieldPath | UpdateData<T>,
+export function updateDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  fieldOrUpdateData: string | FieldPath | UpdateData<DbType>,
   value?: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void> {
-  reference = cast<DocumentReference<unknown>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
   const firestore = cast(reference.firestore, Firestore);
 
   const dataReader = newUserDataReader(firestore);
@@ -376,8 +429,13 @@ export function updateDoc<T>(
  * @returns A Promise resolved once the document has been successfully
  * deleted from the backend (note that it won't resolve while you're offline).
  */
-export function deleteDoc(
-  reference: DocumentReference<unknown>
+export function deleteDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>
 ): Promise<void> {
   const firestore = cast(reference.firestore, Firestore);
   const mutations = [new DeleteMutation(reference._key, Precondition.none())];
@@ -394,10 +452,15 @@ export function deleteDoc(
  * newly created document after it has been written to the backend (Note that it
  * won't resolve while you're offline).
  */
-export function addDoc<T>(
-  reference: CollectionReference<T>,
-  data: WithFieldValue<T>
-): Promise<DocumentReference<T>> {
+export function addDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: CollectionReference<AppType, DbType>,
+  data: WithFieldValue<AppType>
+): Promise<DocumentReference<AppType, DbType>> {
   const firestore = cast(reference.firestore, Firestore);
 
   const docRef = doc(reference);
@@ -441,10 +504,15 @@ export interface Unsubscribe {
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  reference: DocumentReference<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
   observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
   }
@@ -463,11 +531,16 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  reference: DocumentReference<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
   options: SnapshotListenOptions,
   observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
   }
@@ -490,9 +563,14 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  reference: DocumentReference<T>,
-  onNext: (snapshot: DocumentSnapshot<T>) => void,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
+  onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void,
   onError?: (error: FirestoreError) => void,
   onCompletion?: () => void
 ): Unsubscribe;
@@ -515,10 +593,15 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  reference: DocumentReference<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>,
   options: SnapshotListenOptions,
-  onNext: (snapshot: DocumentSnapshot<T>) => void,
+  onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void,
   onError?: (error: FirestoreError) => void,
   onCompletion?: () => void
 ): Unsubscribe;
@@ -536,10 +619,15 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  query: Query<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>,
   observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
   }
@@ -559,11 +647,16 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  query: Query<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>,
   options: SnapshotListenOptions,
   observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
   }
@@ -587,9 +680,14 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  query: Query<T>,
-  onNext: (snapshot: QuerySnapshot<T>) => void,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>,
+  onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void,
   onError?: (error: FirestoreError) => void,
   onCompletion?: () => void
 ): Unsubscribe;
@@ -613,10 +711,15 @@ export function onSnapshot<T>(
  * @returns An unsubscribe function that can be called to cancel
  * the snapshot listener.
  */
-export function onSnapshot<T>(
-  query: Query<T>,
+export function onSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>,
   options: SnapshotListenOptions,
-  onNext: (snapshot: QuerySnapshot<T>) => void,
+  onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void,
   onError?: (error: FirestoreError) => void,
   onCompletion?: () => void
 ): Unsubscribe;
@@ -776,11 +879,11 @@ export function executeWrite(
  * Converts a {@link ViewSnapshot} that contains the single document specified by `ref`
  * to a {@link DocumentSnapshot}.
  */
-function convertToDocSnapshot<T>(
+function convertToDocSnapshot<AppType, DbType extends DocumentData>(
   firestore: Firestore,
-  ref: DocumentReference<T>,
+  ref: DocumentReference<AppType, DbType>,
   snapshot: ViewSnapshot
-): DocumentSnapshot<T> {
+): DocumentSnapshot<AppType, DbType> {
   debugAssert(
     snapshot.docs.size <= 1,
     'Expected zero or a single result on a document-only query'
@@ -788,7 +891,7 @@ function convertToDocSnapshot<T>(
   const doc = snapshot.docs.get(ref._key);
 
   const userDataWriter = new ExpUserDataWriter(firestore);
-  return new DocumentSnapshot(
+  return new DocumentSnapshot<AppType, DbType>(
     firestore,
     userDataWriter,
     ref._key,
diff --git a/packages/firestore/src/api/snapshot.ts b/packages/firestore/src/api/snapshot.ts
index 658cb728da4..215802bf901 100644
--- a/packages/firestore/src/api/snapshot.ts
+++ b/packages/firestore/src/api/snapshot.ts
@@ -42,8 +42,8 @@ import { Firestore } from './database';
 import { SnapshotListenOptions } from './reference_impl';
 
 /**
- * Converter used by `withConverter()` to transform user objects of type `T`
- * into Firestore data.
+ * Converter used by `withConverter()` to transform user objects of type
+ * `AppType` into Firestore data.
  *
  * Using the converter allows you to specify generic type arguments when
  * storing and retrieving objects from Firestore.
@@ -58,7 +58,7 @@ import { SnapshotListenOptions } from './reference_impl';
  *   }
  * }
  *
- * const postConverter = {
+ * const postConverter: FirestoreDataConverter<Post, DocumentData> = {
  *   toFirestore(post: WithFieldValue<Post>): DocumentData {
  *     return {title: post.title, author: post.author};
  *   },
@@ -83,8 +83,7 @@ import { SnapshotListenOptions } from './reference_impl';
  * }
  * ```
  */
-export interface FirestoreDataConverter<T>
-  extends LiteFirestoreDataConverter<T> {
+export interface FirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends LiteFirestoreDataConverter<AppType, DbType> {
   /**
    * Called by the Firestore SDK to convert a custom model object of type `T`
    * into a plain JavaScript object (suitable for writing directly to the
@@ -94,7 +93,7 @@ export interface FirestoreDataConverter<T>
    * The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as
    * {@link (deleteField:1)} to be used as property values.
    */
-  toFirestore(modelObject: WithFieldValue<T>): DocumentData;
+  toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 
   /**
    * Called by the Firestore SDK to convert a custom model object of type `T`
@@ -108,9 +107,9 @@ export interface FirestoreDataConverter<T>
    * omitted.
    */
   toFirestore(
-    modelObject: PartialWithFieldValue<T>,
+    modelObject: PartialWithFieldValue<AppType>,
     options: SetOptions
-  ): DocumentData;
+  ): PartialWithFieldValue<DbType>;
 
   /**
    * Called by the Firestore SDK to convert Firestore data into an object of
@@ -120,9 +119,9 @@ export interface FirestoreDataConverter<T>
    * @param options - The `SnapshotOptions` from the initial call to `data()`.
    */
   fromFirestore(
-    snapshot: QueryDocumentSnapshot<DocumentData>,
+    snapshot: QueryDocumentSnapshot<DbType, DbType>,
     options?: SnapshotOptions
-  ): T;
+  ): AppType;
 }
 
 /**
@@ -200,12 +199,12 @@ export type DocumentChangeType = 'added' | 'removed' | 'modified';
  * A `DocumentChange` represents a change to the documents matching a query.
  * It contains the document affected and the type of change that occurred.
  */
-export interface DocumentChange<T = DocumentData> {
+export interface DocumentChange<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /** The type of change ('added', 'modified', or 'removed'). */
   readonly type: DocumentChangeType;
 
   /** The document affected by this change. */
-  readonly doc: QueryDocumentSnapshot<T>;
+  readonly doc: QueryDocumentSnapshot<AppType, DbType>;
 
   /**
    * The index of the changed document in the result set immediately prior to
@@ -232,9 +231,7 @@ export interface DocumentChange<T = DocumentData> {
  * access will return 'undefined'. You can use the `exists()` method to
  * explicitly verify a document's existence.
  */
-export class DocumentSnapshot<
-  T = DocumentData
-> extends LiteDocumentSnapshot<T> {
+export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends LiteDocumentSnapshot<AppType, DbType> {
   private readonly _firestoreImpl: Firestore;
 
   /**
@@ -250,7 +247,7 @@ export class DocumentSnapshot<
     key: DocumentKey,
     document: Document | null,
     metadata: SnapshotMetadata,
-    converter: UntypedFirestoreDataConverter<T> | null
+    converter: UntypedFirestoreDataConverter<AppType, DbType> | null
   ) {
     super(_firestore, userDataWriter, key, document, converter);
     this._firestoreImpl = _firestore;
@@ -260,7 +257,7 @@ export class DocumentSnapshot<
   /**
    * Returns whether or not the data exists. True if the document exists.
    */
-  exists(): this is QueryDocumentSnapshot<T> {
+  exists(): this is QueryDocumentSnapshot<AppType, DbType> {
     return super.exists();
   }
 
@@ -278,7 +275,7 @@ export class DocumentSnapshot<
    * @returns An `Object` containing all fields in the document or `undefined` if
    * the document doesn't exist.
    */
-  data(options: SnapshotOptions = {}): T | undefined {
+  data(options: SnapshotOptions = {}): AppType | undefined {
     if (!this._document) {
       return undefined;
     } else if (this._converter) {
@@ -297,7 +294,7 @@ export class DocumentSnapshot<
       return this._userDataWriter.convertValue(
         this._document.data.value,
         options.serverTimestamps
-      ) as T;
+      ) as AppType;
     }
   }
 
@@ -346,9 +343,7 @@ export class DocumentSnapshot<
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<
-  T = DocumentData
-> extends DocumentSnapshot<T> {
+export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *
@@ -362,8 +357,8 @@ export class QueryDocumentSnapshot<
    * have not yet been set to their final value).
    * @returns An `Object` containing all fields in the document.
    */
-  data(options: SnapshotOptions = {}): T {
-    return super.data(options) as T;
+  data(options: SnapshotOptions = {}): AppType {
+    return super.data(options) as AppType;
   }
 }
 
@@ -374,7 +369,7 @@ export class QueryDocumentSnapshot<
  * number of documents can be determined via the `empty` and `size`
  * properties.
  */
-export class QuerySnapshot<T = DocumentData> {
+export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
   /**
    * Metadata about this snapshot, concerning its source and if it has local
    * modifications.
@@ -385,16 +380,16 @@ export class QuerySnapshot<T = DocumentData> {
    * The query on which you called `get` or `onSnapshot` in order to get this
    * `QuerySnapshot`.
    */
-  readonly query: Query<T>;
+  readonly query: Query<AppType, DbType>;
 
-  private _cachedChanges?: Array<DocumentChange<T>>;
+  private _cachedChanges?: Array<DocumentChange<AppType, DbType>>;
   private _cachedChangesIncludeMetadataChanges?: boolean;
 
   /** @hideconstructor */
   constructor(
     readonly _firestore: Firestore,
     readonly _userDataWriter: AbstractUserDataWriter,
-    query: Query<T>,
+    query: Query<AppType, DbType>,
     readonly _snapshot: ViewSnapshot
   ) {
     this.metadata = new SnapshotMetadata(
@@ -405,8 +400,8 @@ export class QuerySnapshot<T = DocumentData> {
   }
 
   /** An array of all the documents in the `QuerySnapshot`. */
-  get docs(): Array<QueryDocumentSnapshot<T>> {
-    const result: Array<QueryDocumentSnapshot<T>> = [];
+  get docs(): Array<QueryDocumentSnapshot<AppType, DbType>> {
+    const result: Array<QueryDocumentSnapshot<AppType, DbType>> = [];
     this.forEach(doc => result.push(doc));
     return result;
   }
@@ -429,13 +424,13 @@ export class QuerySnapshot<T = DocumentData> {
    * @param thisArg - The `this` binding for the callback.
    */
   forEach(
-    callback: (result: QueryDocumentSnapshot<T>) => void,
+    callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void,
     thisArg?: unknown
   ): void {
     this._snapshot.docs.forEach(doc => {
       callback.call(
         thisArg,
-        new QueryDocumentSnapshot<T>(
+        new QueryDocumentSnapshot<AppType, DbType>(
           this._firestore,
           this._userDataWriter,
           doc.key,
@@ -459,7 +454,7 @@ export class QuerySnapshot<T = DocumentData> {
    * changes (i.e. only `DocumentSnapshot.metadata` changed) should trigger
    * snapshot events.
    */
-  docChanges(options: SnapshotListenOptions = {}): Array<DocumentChange<T>> {
+  docChanges(options: SnapshotListenOptions = {}): Array<DocumentChange<AppType, DbType>> {
     const includeMetadataChanges = !!options.includeMetadataChanges;
 
     if (includeMetadataChanges && this._snapshot.excludesMetadataChanges) {
@@ -483,10 +478,10 @@ export class QuerySnapshot<T = DocumentData> {
 }
 
 /** Calculates the array of `DocumentChange`s for a given `ViewSnapshot`. */
-export function changesFromSnapshot<T>(
-  querySnapshot: QuerySnapshot<T>,
+export function changesFromSnapshot<AppType, DbType extends DocumentData>(
+  querySnapshot: QuerySnapshot<AppType, DbType>,
   includeMetadataChanges: boolean
-): Array<DocumentChange<T>> {
+): Array<DocumentChange<AppType, DbType>> {
   if (querySnapshot._snapshot.oldDocs.isEmpty()) {
     // Special case the first snapshot because index calculation is easy and
     // fast
@@ -505,7 +500,7 @@ export function changesFromSnapshot<T>(
           ) < 0,
         'Got added events in wrong order'
       );
-      const doc = new QueryDocumentSnapshot<T>(
+      const doc = new QueryDocumentSnapshot<AppType, DbType>(
         querySnapshot._firestore,
         querySnapshot._userDataWriter,
         change.doc.key,
@@ -533,7 +528,7 @@ export function changesFromSnapshot<T>(
         change => includeMetadataChanges || change.type !== ChangeType.Metadata
       )
       .map(change => {
-        const doc = new QueryDocumentSnapshot<T>(
+        const doc = new QueryDocumentSnapshot<AppType, DbType>(
           querySnapshot._firestore,
           querySnapshot._userDataWriter,
           change.doc.key,
@@ -588,10 +583,7 @@ export function resultChangeType(type: ChangeType): DocumentChangeType {
  * @param right - A snapshot to compare.
  * @returns true if the snapshots are equal.
  */
-export function snapshotEqual<T>(
-  left: DocumentSnapshot<T> | QuerySnapshot<T>,
-  right: DocumentSnapshot<T> | QuerySnapshot<T>
-): boolean {
+export function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean {
   if (left instanceof DocumentSnapshot && right instanceof DocumentSnapshot) {
     return (
       left._firestore === right._firestore &&
diff --git a/packages/firestore/src/api/transaction.ts b/packages/firestore/src/api/transaction.ts
index a70cfba231d..2bb7954d0d2 100644
--- a/packages/firestore/src/api/transaction.ts
+++ b/packages/firestore/src/api/transaction.ts
@@ -22,7 +22,7 @@ import {
   DEFAULT_TRANSACTION_OPTIONS,
   validateTransactionOptions
 } from '../core/transaction_options';
-import { DocumentReference } from '../lite-api/reference';
+import {DocumentData, DocumentReference} from '../lite-api/reference';
 import { Transaction as LiteTransaction } from '../lite-api/transaction';
 import { validateReference } from '../lite-api/write_batch';
 import { cast } from '../util/input_validation';
@@ -57,8 +57,8 @@ export class Transaction extends LiteTransaction {
    * @param documentRef - A reference to the document to be read.
    * @returns A `DocumentSnapshot` with the read data.
    */
-  get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>> {
-    const ref = validateReference<T>(documentRef, this._firestore);
+  get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
+    const ref = validateReference<AppType, DbType>(documentRef, this._firestore);
     const userDataWriter = new ExpUserDataWriter(this._firestore);
     return super
       .get(documentRef)

From e14de0b5e661b351fd0e1f3263b46d5b89ad8a14 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 12:52:27 -0400
Subject: [PATCH 6/9] firestore[-lite].api.md update

---
 common/api-review/firestore-lite.api.md | 132 +++++++++---------
 common/api-review/firestore.api.md      | 170 ++++++++++++------------
 2 files changed, 149 insertions(+), 153 deletions(-)

diff --git a/common/api-review/firestore-lite.api.md b/common/api-review/firestore-lite.api.md
index 35802afacb7..b370ddb8c99 100644
--- a/common/api-review/firestore-lite.api.md
+++ b/common/api-review/firestore-lite.api.md
@@ -10,7 +10,7 @@ import { FirebaseError } from '@firebase/util';
 import { LogLevelString as LogLevel } from '@firebase/logger';
 
 // @public
-export function addDoc<T>(reference: CollectionReference<T>, data: WithFieldValue<T>): Promise<DocumentReference<T>>;
+export function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<DocumentReference<AppType, DbType>>;
 
 // @public
 export type AddPrefixToKeys<Prefix extends string, T extends Record<string, unknown>> = {
@@ -26,14 +26,14 @@ export class AggregateField<T> {
 export type AggregateFieldType = AggregateField<number | null>;
 
 // @public
-export class AggregateQuerySnapshot<T extends AggregateSpec> {
-    data(): AggregateSpecData<T>;
-    readonly query: Query<unknown>;
+export class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    data(): AggregateSpecData<AggregateSpecType>;
+    readonly query: Query<AppType, DbType>;
     readonly type = "AggregateQuerySnapshot";
 }
 
 // @public
-export function aggregateQuerySnapshotEqual<T extends AggregateSpec>(left: AggregateQuerySnapshot<T>, right: AggregateQuerySnapshot<T>): boolean;
+export function aggregateQuerySnapshotEqual<AggregateSpecType extends AggregateSpec>(left: AggregateQuerySnapshot<AggregateSpecType>, right: AggregateQuerySnapshot<AggregateSpecType>): boolean;
 
 // @public
 export interface AggregateSpec {
@@ -69,25 +69,25 @@ export class Bytes {
 export type ChildUpdateFields<K extends string, V> = V extends Record<string, unknown> ? AddPrefixToKeys<K, UpdateData<V>> : never;
 
 // @public
-export function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collection(reference: CollectionReference<unknown>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collection(reference: DocumentReference, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData>;
+export function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData, DocumentData>;
 
 // @public
-export class CollectionReference<T = DocumentData> extends Query<T> {
+export class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> {
     get id(): string;
-    get parent(): DocumentReference<DocumentData> | null;
+    get parent(): DocumentReference<DocumentData, DocumentData> | null;
     get path(): string;
     readonly type = "collection";
-    withConverter<U>(converter: FirestoreDataConverter<U>): CollectionReference<U>;
-    withConverter(converter: null): CollectionReference<DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): CollectionReference<NewAppType, NewDbType>;
+    withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
 }
 
 // @public
@@ -96,48 +96,46 @@ export function connectFirestoreEmulator(firestore: Firestore, host: string, por
 }): void;
 
 // @public
-export function deleteDoc(reference: DocumentReference<unknown>): Promise<void>;
+export function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<void>;
 
 // @public
 export function deleteField(): FieldValue;
 
 // @public
-export function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 
 // @public
-export function doc<T>(reference: CollectionReference<T>, path?: string, ...pathSegments: string[]): DocumentReference<T>;
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path?: string, ...pathSegments: string[]): DocumentReference<AppType, DbType>;
 
 // @public
-export function doc(reference: DocumentReference<unknown>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 
 // @public
-export interface DocumentData {
-    [field: string]: any;
-}
+export type DocumentData = Record<string, any>;
 
 // @public
 export function documentId(): FieldPath;
 
 // @public
-export class DocumentReference<T = DocumentData> {
-    readonly converter: FirestoreDataConverter<T> | null;
+export class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null;
     readonly firestore: Firestore;
     get id(): string;
-    get parent(): CollectionReference<T>;
+    get parent(): CollectionReference<AppType, DbType>;
     get path(): string;
     readonly type = "document";
-    withConverter<U>(converter: FirestoreDataConverter<U>): DocumentReference<U>;
-    withConverter(converter: null): DocumentReference<DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
+    withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
 }
 
 // @public
-export class DocumentSnapshot<T = DocumentData> {
+export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
     protected constructor();
-    data(): T | undefined;
-    exists(): this is QueryDocumentSnapshot<T>;
+    data(): AppType | undefined;
+    exists(): this is QueryDocumentSnapshot<AppType, DbType>;
     get(fieldPath: string | FieldPath): any;
     get id(): string;
-    get ref(): DocumentReference<T>;
+    get ref(): DocumentReference<AppType, DbType>;
 }
 
 export { EmulatorMockTokenOptions }
@@ -173,10 +171,10 @@ export class Firestore {
 }
 
 // @public
-export interface FirestoreDataConverter<T> {
-    fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>): T;
-    toFirestore(modelObject: WithFieldValue<T>): DocumentData;
-    toFirestore(modelObject: PartialWithFieldValue<T>, options: SetOptions): DocumentData;
+export interface FirestoreDataConverter<AppType, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    fromFirestore(snapshot: QueryDocumentSnapshot<DbType, DbType>): AppType;
+    toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
+    toFirestore(modelObject: PartialWithFieldValue<AppType>, options: SetOptions): PartialWithFieldValue<DbType>;
 }
 
 // @public
@@ -202,15 +200,15 @@ export class GeoPoint {
 }
 
 // @public
-export function getCount(query: Query<unknown>): Promise<AggregateQuerySnapshot<{
+export function getCount<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{
     count: AggregateField<number>;
-}>>;
+}, AppType, DbType>>;
 
 // @public
-export function getDoc<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 
 // @public
-export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 
 // @public
 export function getFirestore(): Firestore;
@@ -255,20 +253,20 @@ export type PartialWithFieldValue<T> = Partial<T> | (T extends Primitive ? T : T
 export type Primitive = string | number | boolean | undefined | null;
 
 // @public
-export class Query<T = DocumentData> {
+export class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
     protected constructor();
-    readonly converter: FirestoreDataConverter<T> | null;
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null;
     readonly firestore: Firestore;
     readonly type: 'query' | 'collection';
-    withConverter(converter: null): Query<DocumentData>;
-    withConverter<U>(converter: FirestoreDataConverter<U>): Query<U>;
+    withConverter(converter: null): Query<DocumentData, DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
 }
 
 // @public
-export function query<T>(query: Query<T>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<T>;
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<AppType, DbType>;
 
 // @public
-export function query<T>(query: Query<T>, ...queryConstraints: QueryConstraint[]): Query<T>;
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, ...queryConstraints: QueryConstraint[]): Query<AppType, DbType>;
 
 // @public
 export class QueryCompositeFilterConstraint {
@@ -284,9 +282,9 @@ export abstract class QueryConstraint {
 export type QueryConstraintType = 'where' | 'orderBy' | 'limit' | 'limitToLast' | 'startAt' | 'startAfter' | 'endAt' | 'endBefore';
 
 // @public
-export class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<T> {
+export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
     // @override
-    data(): T;
+    data(): AppType;
 }
 
 // @public
@@ -295,7 +293,7 @@ export class QueryEndAtConstraint extends QueryConstraint {
 }
 
 // @public
-export function queryEqual<T>(left: Query<T>, right: Query<T>): boolean;
+export function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean;
 
 // @public
 export class QueryFieldFilterConstraint extends QueryConstraint {
@@ -319,11 +317,11 @@ export class QueryOrderByConstraint extends QueryConstraint {
 }
 
 // @public
-export class QuerySnapshot<T = DocumentData> {
-    get docs(): Array<QueryDocumentSnapshot<T>>;
+export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    get docs(): Array<QueryDocumentSnapshot<AppType, DbType>>;
     get empty(): boolean;
-    forEach(callback: (result: QueryDocumentSnapshot<T>) => void, thisArg?: unknown): void;
-    readonly query: Query<T>;
+    forEach(callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void, thisArg?: unknown): void;
+    readonly query: Query<AppType, DbType>;
     get size(): number;
 }
 
@@ -333,7 +331,7 @@ export class QueryStartAtConstraint extends QueryConstraint {
 }
 
 // @public
-export function refEqual<T>(left: DocumentReference<T> | CollectionReference<T>, right: DocumentReference<T> | CollectionReference<T>): boolean;
+export function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>, right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>): boolean;
 
 // @public
 export function runTransaction<T>(firestore: Firestore, updateFunction: (transaction: Transaction) => Promise<T>, options?: TransactionOptions): Promise<T>;
@@ -342,10 +340,10 @@ export function runTransaction<T>(firestore: Firestore, updateFunction: (transac
 export function serverTimestamp(): FieldValue;
 
 // @public
-export function setDoc<T>(reference: DocumentReference<T>, data: WithFieldValue<T>): Promise<void>;
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<void>;
 
 // @public
-export function setDoc<T>(reference: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): Promise<void>;
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): Promise<void>;
 
 // @public
 export function setLogLevel(logLevel: LogLevel): void;
@@ -365,7 +363,7 @@ export interface Settings {
 }
 
 // @public
-export function snapshotEqual<T>(left: DocumentSnapshot<T> | QuerySnapshot<T>, right: DocumentSnapshot<T> | QuerySnapshot<T>): boolean;
+export function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean;
 
 // @public
 export function startAfter(snapshot: DocumentSnapshot<unknown>): QueryStartAtConstraint;
@@ -405,12 +403,12 @@ export class Timestamp {
 
 // @public
 export class Transaction {
-    delete(documentRef: DocumentReference<unknown>): this;
-    get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
-    set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): this;
-    set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): this;
-    update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): this;
-    update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
+    delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): this;
+    get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): this;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): this;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): this;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
 }
 
 // @public
@@ -427,10 +425,10 @@ export type UpdateData<T> = T extends Primitive ? T : T extends {} ? {
 } & NestedUpdateFields<T> : Partial<T>;
 
 // @public
-export function updateDoc<T>(reference: DocumentReference<T>, data: UpdateData<T>): Promise<void>;
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): Promise<void>;
 
 // @public
-export function updateDoc(reference: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
 
 // @public
 export function where(fieldPath: string | FieldPath, opStr: WhereFilterOp, value: unknown): QueryFieldFilterConstraint;
@@ -446,11 +444,11 @@ export type WithFieldValue<T> = T | (T extends Primitive ? T : T extends {} ? {
 // @public
 export class WriteBatch {
     commit(): Promise<void>;
-    delete(documentRef: DocumentReference<unknown>): WriteBatch;
-    set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): WriteBatch;
-    set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): WriteBatch;
-    update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): WriteBatch;
-    update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
+    delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): WriteBatch;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): WriteBatch;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): WriteBatch;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): WriteBatch;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
 }
 
 // @public
diff --git a/common/api-review/firestore.api.md b/common/api-review/firestore.api.md
index 53e8e60cab8..ac569497641 100644
--- a/common/api-review/firestore.api.md
+++ b/common/api-review/firestore.api.md
@@ -10,7 +10,7 @@ import { FirebaseError } from '@firebase/util';
 import { LogLevelString as LogLevel } from '@firebase/logger';
 
 // @public
-export function addDoc<T>(reference: CollectionReference<T>, data: WithFieldValue<T>): Promise<DocumentReference<T>>;
+export function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<DocumentReference<AppType, DbType>>;
 
 // @public
 export type AddPrefixToKeys<Prefix extends string, T extends Record<string, unknown>> = {
@@ -26,14 +26,14 @@ export class AggregateField<T> {
 export type AggregateFieldType = AggregateField<number | null>;
 
 // @public
-export class AggregateQuerySnapshot<T extends AggregateSpec> {
-    data(): AggregateSpecData<T>;
-    readonly query: Query<unknown>;
+export class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    data(): AggregateSpecData<AggregateSpecType>;
+    readonly query: Query<AppType, DbType>;
     readonly type = "AggregateQuerySnapshot";
 }
 
 // @public
-export function aggregateQuerySnapshotEqual<T extends AggregateSpec>(left: AggregateQuerySnapshot<T>, right: AggregateQuerySnapshot<T>): boolean;
+export function aggregateQuerySnapshotEqual<AggregateSpecType extends AggregateSpec>(left: AggregateQuerySnapshot<AggregateSpecType>, right: AggregateQuerySnapshot<AggregateSpecType>): boolean;
 
 // @public
 export interface AggregateSpec {
@@ -75,25 +75,25 @@ export type ChildUpdateFields<K extends string, V> = V extends Record<string, un
 export function clearIndexedDbPersistence(firestore: Firestore): Promise<void>;
 
 // @public
-export function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collection(reference: CollectionReference<unknown>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collection(reference: DocumentReference, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 
 // @public
-export function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData>;
+export function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData, DocumentData>;
 
 // @public
-export class CollectionReference<T = DocumentData> extends Query<T> {
+export class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> {
     get id(): string;
-    get parent(): DocumentReference<DocumentData> | null;
+    get parent(): DocumentReference<DocumentData, DocumentData> | null;
     get path(): string;
     readonly type = "collection";
-    withConverter<U>(converter: FirestoreDataConverter<U>): CollectionReference<U>;
-    withConverter(converter: null): CollectionReference<DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): CollectionReference<NewAppType, NewDbType>;
+    withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
 }
 
 // @public
@@ -102,7 +102,7 @@ export function connectFirestoreEmulator(firestore: Firestore, host: string, por
 }): void;
 
 // @public
-export function deleteDoc(reference: DocumentReference<unknown>): Promise<void>;
+export function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<void>;
 
 // @public
 export function deleteField(): FieldValue;
@@ -111,17 +111,17 @@ export function deleteField(): FieldValue;
 export function disableNetwork(firestore: Firestore): Promise<void>;
 
 // @public
-export function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 
 // @public
-export function doc<T>(reference: CollectionReference<T>, path?: string, ...pathSegments: string[]): DocumentReference<T>;
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path?: string, ...pathSegments: string[]): DocumentReference<AppType, DbType>;
 
 // @public
-export function doc(reference: DocumentReference<unknown>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 
 // @public
-export interface DocumentChange<T = DocumentData> {
-    readonly doc: QueryDocumentSnapshot<T>;
+export interface DocumentChange<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    readonly doc: QueryDocumentSnapshot<AppType, DbType>;
     readonly newIndex: number;
     readonly oldIndex: number;
     readonly type: DocumentChangeType;
@@ -131,34 +131,32 @@ export interface DocumentChange<T = DocumentData> {
 export type DocumentChangeType = 'added' | 'removed' | 'modified';
 
 // @public
-export interface DocumentData {
-    [field: string]: any;
-}
+export type DocumentData = Record<string, any>;
 
 // @public
 export function documentId(): FieldPath;
 
 // @public
-export class DocumentReference<T = DocumentData> {
-    readonly converter: FirestoreDataConverter<T> | null;
+export class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null;
     readonly firestore: Firestore;
     get id(): string;
-    get parent(): CollectionReference<T>;
+    get parent(): CollectionReference<AppType, DbType>;
     get path(): string;
     readonly type = "document";
-    withConverter<U>(converter: FirestoreDataConverter<U>): DocumentReference<U>;
-    withConverter(converter: null): DocumentReference<DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
+    withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
 }
 
 // @public
-export class DocumentSnapshot<T = DocumentData> {
+export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
     protected constructor();
-    data(options?: SnapshotOptions): T | undefined;
-    exists(): this is QueryDocumentSnapshot<T>;
+    data(options?: SnapshotOptions): AppType | undefined;
+    exists(): this is QueryDocumentSnapshot<AppType, DbType>;
     get(fieldPath: string | FieldPath, options?: SnapshotOptions): any;
     get id(): string;
     readonly metadata: SnapshotMetadata;
-    get ref(): DocumentReference<T>;
+    get ref(): DocumentReference<AppType, DbType>;
 }
 
 export { EmulatorMockTokenOptions }
@@ -203,10 +201,10 @@ export class Firestore {
 }
 
 // @public
-export interface FirestoreDataConverter<T> {
-    fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>, options?: SnapshotOptions): T;
-    toFirestore(modelObject: WithFieldValue<T>): DocumentData;
-    toFirestore(modelObject: PartialWithFieldValue<T>, options: SetOptions): DocumentData;
+export interface FirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    fromFirestore(snapshot: QueryDocumentSnapshot<DbType, DbType>, options?: SnapshotOptions): AppType;
+    toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
+    toFirestore(modelObject: PartialWithFieldValue<AppType>, options: SetOptions): PartialWithFieldValue<DbType>;
 }
 
 // @public
@@ -246,27 +244,27 @@ export class GeoPoint {
 }
 
 // @public
-export function getCountFromServer(query: Query<unknown>): Promise<AggregateQuerySnapshot<{
+export function getCountFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{
     count: AggregateField<number>;
-}>>;
+}, AppType, DbType>>;
 
 // @public
-export function getDoc<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 
 // @public
-export function getDocFromCache<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export function getDocFromCache<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 
 // @public
-export function getDocFromServer<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export function getDocFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 
 // @public
-export function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 
 // @public
-export function getDocsFromCache<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export function getDocsFromCache<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 
 // @public
-export function getDocsFromServer<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export function getDocsFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 
 // @public
 export function getFirestore(app: FirebaseApp): Firestore;
@@ -377,44 +375,44 @@ export type NestedUpdateFields<T extends Record<string, unknown>> = UnionToInter
 }[keyof T & string]>;
 
 // @public
-export function onSnapshot<T>(reference: DocumentReference<T>, observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, observer: {
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(reference: DocumentReference<T>, options: SnapshotListenOptions, observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, options: SnapshotListenOptions, observer: {
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(reference: DocumentReference<T>, onNext: (snapshot: DocumentSnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(reference: DocumentReference<T>, options: SnapshotListenOptions, onNext: (snapshot: DocumentSnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, options: SnapshotListenOptions, onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(query: Query<T>, observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, observer: {
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(query: Query<T>, options: SnapshotListenOptions, observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, options: SnapshotListenOptions, observer: {
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(query: Query<T>, onNext: (snapshot: QuerySnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 
 // @public
-export function onSnapshot<T>(query: Query<T>, options: SnapshotListenOptions, onNext: (snapshot: QuerySnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, options: SnapshotListenOptions, onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 
 // @public
 export function onSnapshotsInSync(firestore: Firestore, observer: {
@@ -490,20 +488,20 @@ export type PersistentTabManager = PersistentSingleTabManager | PersistentMultip
 export type Primitive = string | number | boolean | undefined | null;
 
 // @public
-export class Query<T = DocumentData> {
+export class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
     protected constructor();
-    readonly converter: FirestoreDataConverter<T> | null;
+    readonly converter: FirestoreDataConverter<AppType, DbType> | null;
     readonly firestore: Firestore;
     readonly type: 'query' | 'collection';
-    withConverter(converter: null): Query<DocumentData>;
-    withConverter<U>(converter: FirestoreDataConverter<U>): Query<U>;
+    withConverter(converter: null): Query<DocumentData, DocumentData>;
+    withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
 }
 
 // @public
-export function query<T>(query: Query<T>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<T>;
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<AppType, DbType>;
 
 // @public
-export function query<T>(query: Query<T>, ...queryConstraints: QueryConstraint[]): Query<T>;
+export function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, ...queryConstraints: QueryConstraint[]): Query<AppType, DbType>;
 
 // @public
 export class QueryCompositeFilterConstraint {
@@ -519,9 +517,9 @@ export abstract class QueryConstraint {
 export type QueryConstraintType = 'where' | 'orderBy' | 'limit' | 'limitToLast' | 'startAt' | 'startAfter' | 'endAt' | 'endBefore';
 
 // @public
-export class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<T> {
+export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
     // @override
-    data(options?: SnapshotOptions): T;
+    data(options?: SnapshotOptions): AppType;
 }
 
 // @public
@@ -530,7 +528,7 @@ export class QueryEndAtConstraint extends QueryConstraint {
 }
 
 // @public
-export function queryEqual<T>(left: Query<T>, right: Query<T>): boolean;
+export function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean;
 
 // @public
 export class QueryFieldFilterConstraint extends QueryConstraint {
@@ -554,13 +552,13 @@ export class QueryOrderByConstraint extends QueryConstraint {
 }
 
 // @public
-export class QuerySnapshot<T = DocumentData> {
-    docChanges(options?: SnapshotListenOptions): Array<DocumentChange<T>>;
-    get docs(): Array<QueryDocumentSnapshot<T>>;
+export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+    docChanges(options?: SnapshotListenOptions): Array<DocumentChange<AppType, DbType>>;
+    get docs(): Array<QueryDocumentSnapshot<AppType, DbType>>;
     get empty(): boolean;
-    forEach(callback: (result: QueryDocumentSnapshot<T>) => void, thisArg?: unknown): void;
+    forEach(callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void, thisArg?: unknown): void;
     readonly metadata: SnapshotMetadata;
-    readonly query: Query<T>;
+    readonly query: Query<AppType, DbType>;
     get size(): number;
 }
 
@@ -570,7 +568,7 @@ export class QueryStartAtConstraint extends QueryConstraint {
 }
 
 // @public
-export function refEqual<T>(left: DocumentReference<T> | CollectionReference<T>, right: DocumentReference<T> | CollectionReference<T>): boolean;
+export function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>, right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>): boolean;
 
 // @public
 export function runTransaction<T>(firestore: Firestore, updateFunction: (transaction: Transaction) => Promise<T>, options?: TransactionOptions): Promise<T>;
@@ -579,10 +577,10 @@ export function runTransaction<T>(firestore: Firestore, updateFunction: (transac
 export function serverTimestamp(): FieldValue;
 
 // @public
-export function setDoc<T>(reference: DocumentReference<T>, data: WithFieldValue<T>): Promise<void>;
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<void>;
 
 // @public
-export function setDoc<T>(reference: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): Promise<void>;
+export function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): Promise<void>;
 
 // @beta
 export function setIndexConfiguration(firestore: Firestore, configuration: IndexConfiguration): Promise<void>;
@@ -601,7 +599,7 @@ export type SetOptions = {
 };
 
 // @public
-export function snapshotEqual<T>(left: DocumentSnapshot<T> | QuerySnapshot<T>, right: DocumentSnapshot<T> | QuerySnapshot<T>): boolean;
+export function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean;
 
 // @public
 export interface SnapshotListenOptions {
@@ -661,12 +659,12 @@ export class Timestamp {
 
 // @public
 export class Transaction {
-    delete(documentRef: DocumentReference<unknown>): this;
-    get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
-    set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): this;
-    set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): this;
-    update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): this;
-    update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
+    delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): this;
+    get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): this;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): this;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): this;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
 }
 
 // @public
@@ -688,10 +686,10 @@ export type UpdateData<T> = T extends Primitive ? T : T extends {} ? {
 } & NestedUpdateFields<T> : Partial<T>;
 
 // @public
-export function updateDoc<T>(reference: DocumentReference<T>, data: UpdateData<T>): Promise<void>;
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): Promise<void>;
 
 // @public
-export function updateDoc(reference: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
+export function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
 
 // @public
 export function waitForPendingWrites(firestore: Firestore): Promise<void>;
@@ -710,11 +708,11 @@ export type WithFieldValue<T> = T | (T extends Primitive ? T : T extends {} ? {
 // @public
 export class WriteBatch {
     commit(): Promise<void>;
-    delete(documentRef: DocumentReference<unknown>): WriteBatch;
-    set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): WriteBatch;
-    set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): WriteBatch;
-    update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): WriteBatch;
-    update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
+    delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): WriteBatch;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): WriteBatch;
+    set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): WriteBatch;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): WriteBatch;
+    update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
 }
 
 // @public

From b34e3404c516e2384c53abada57fc356aeab6a57 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 13:01:49 -0400
Subject: [PATCH 7/9] cleanup

---
 packages/firestore/src/api/aggregate.ts      | 34 ++++++++--
 packages/firestore/src/api/reference_impl.ts | 49 +++++++++-----
 packages/firestore/src/api/snapshot.ts       | 70 +++++++++++++++-----
 packages/firestore/src/api/transaction.ts    | 11 ++-
 packages/firestore/src/lite-api/snapshot.ts  |  2 +-
 5 files changed, 126 insertions(+), 40 deletions(-)

diff --git a/packages/firestore/src/api/aggregate.ts b/packages/firestore/src/api/aggregate.ts
index 74d1c68bbfb..4a98e18bb96 100644
--- a/packages/firestore/src/api/aggregate.ts
+++ b/packages/firestore/src/api/aggregate.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import {AggregateField, AggregateSpec, DocumentData, Query} from '../api';
+import { AggregateField, AggregateSpec, DocumentData, Query } from '../api';
 import { AggregateImpl } from '../core/aggregate';
 import { firestoreClientRunAggregateQuery } from '../core/firestore_client';
 import { count } from '../lite-api/aggregate';
@@ -57,7 +57,16 @@ export {
  * retrieved from `snapshot.data().count`, where `snapshot` is the
  * `AggregateQuerySnapshot` to which the returned Promise resolves.
  */
-export function getCountFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>> {
+export function getCountFromServer<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>
+): Promise<
+  AggregateQuerySnapshot<{ count: AggregateField<number> }, AppType, DbType>
+> {
   const countQuerySpec: { count: AggregateField<number> } = {
     count: count()
   };
@@ -99,7 +108,16 @@ export function getCountFromServer<AppType = DocumentData, DbType extends Docume
  * ```
  * @internal TODO (sum/avg) remove when public
  */
-export function getAggregateFromServer<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, aggregateSpec: AggregateSpecType): Promise<AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>> {
+export function getAggregateFromServer<
+  AggregateSpecType extends AggregateSpec,
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  query: Query<AppType, DbType>,
+  aggregateSpec: AggregateSpecType
+): Promise<AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>> {
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -128,7 +146,15 @@ export function getAggregateFromServer<AggregateSpecType extends AggregateSpec,
  * @param aggregateResult Core aggregation result
  * @internal
  */
-function convertToAggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType, DbType extends DocumentData>(firestore: Firestore, query: Query<AppType, DbType>, aggregateResult: ObjectValue): AggregateQuerySnapshot<AggregateSpecType, AppType, DbType> {
+function convertToAggregateQuerySnapshot<
+  AggregateSpecType extends AggregateSpec,
+  AppType,
+  DbType extends DocumentData
+>(
+  firestore: Firestore,
+  query: Query<AppType, DbType>,
+  aggregateResult: ObjectValue
+): AggregateQuerySnapshot<AggregateSpecType, AppType, DbType> {
   const userDataWriter = new ExpUserDataWriter(firestore);
   return new AggregateQuerySnapshot<AggregateSpecType, AppType, DbType>(
     query,
diff --git a/packages/firestore/src/api/reference_impl.ts b/packages/firestore/src/api/reference_impl.ts
index 25316acb056..6f24f9a69ab 100644
--- a/packages/firestore/src/api/reference_impl.ts
+++ b/packages/firestore/src/api/reference_impl.ts
@@ -40,7 +40,8 @@ import { FieldPath } from '../lite-api/field_path';
 import { validateHasExplicitOrderByForLimitToLast } from '../lite-api/query';
 import {
   CollectionReference,
-  doc, DocumentData,
+  doc,
+  DocumentData,
   DocumentReference,
   PartialWithFieldValue,
   Query,
@@ -91,8 +92,18 @@ export interface SnapshotListenOptions {
  * @returns A Promise resolved with a `DocumentSnapshot` containing the
  * current document contents.
  */
-export function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+export function getDoc<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  reference: DocumentReference<AppType, DbType>
+): Promise<DocumentSnapshot<AppType, DbType>> {
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -132,7 +143,10 @@ export function getDocFromCache<
 >(
   reference: DocumentReference<AppType, DbType>
 ): Promise<DocumentSnapshot<AppType, DbType>> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
   const userDataWriter = new ExpUserDataWriter(firestore);
@@ -168,7 +182,10 @@ export function getDocFromServer<
 >(
   reference: DocumentReference<AppType, DbType>
 ): Promise<DocumentSnapshot<AppType, DbType>> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const firestore = cast(reference.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
 
@@ -219,9 +236,7 @@ export function getDocsFromCache<
   DbType extends DocumentData = AppType extends DocumentData
     ? AppType
     : DocumentData
->(
-  query: Query<AppType, DbType>
-): Promise<QuerySnapshot<AppType, DbType>> {
+>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
   query = cast<Query<AppType, DbType>>(query, Query);
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
@@ -243,9 +258,7 @@ export function getDocsFromServer<
   DbType extends DocumentData = AppType extends DocumentData
     ? AppType
     : DocumentData
->(
-  query: Query<AppType, DbType>
-): Promise<QuerySnapshot<AppType, DbType>> {
+>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>> {
   query = cast<Query<AppType, DbType>>(query, Query);
   const firestore = cast(query.firestore, Firestore);
   const client = ensureFirestoreConfigured(firestore);
@@ -307,7 +320,10 @@ export function setDoc<
   data: PartialWithFieldValue<AppType>,
   options?: SetOptions
 ): Promise<void> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const firestore = cast(reference.firestore, Firestore);
 
   const convertedValue = applyFirestoreDataConverter(
@@ -387,7 +403,10 @@ export function updateDoc<
   value?: unknown,
   ...moreFieldsAndValues: unknown[]
 ): Promise<void> {
-  reference = cast<DocumentReference<AppType, DbType>>(reference, DocumentReference);
+  reference = cast<DocumentReference<AppType, DbType>>(
+    reference,
+    DocumentReference
+  );
   const firestore = cast(reference.firestore, Firestore);
 
   const dataReader = newUserDataReader(firestore);
@@ -434,9 +453,7 @@ export function deleteDoc<
   DbType extends DocumentData = AppType extends DocumentData
     ? AppType
     : DocumentData
->(
-  reference: DocumentReference<AppType, DbType>
-): Promise<void> {
+>(reference: DocumentReference<AppType, DbType>): Promise<void> {
   const firestore = cast(reference.firestore, Firestore);
   const mutations = [new DeleteMutation(reference._key, Precondition.none())];
   return executeWrite(firestore, mutations);
diff --git a/packages/firestore/src/api/snapshot.ts b/packages/firestore/src/api/snapshot.ts
index 215802bf901..efe71735df4 100644
--- a/packages/firestore/src/api/snapshot.ts
+++ b/packages/firestore/src/api/snapshot.ts
@@ -83,12 +83,18 @@ import { SnapshotListenOptions } from './reference_impl';
  * }
  * ```
  */
-export interface FirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends LiteFirestoreDataConverter<AppType, DbType> {
+export interface FirestoreDataConverter<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> extends LiteFirestoreDataConverter<AppType, DbType> {
   /**
-   * Called by the Firestore SDK to convert a custom model object of type `T`
-   * into a plain JavaScript object (suitable for writing directly to the
-   * Firestore database). To use `set()` with `merge` and `mergeFields`,
-   * `toFirestore()` must be defined with `PartialWithFieldValue<T>`.
+   * Called by the Firestore SDK to convert a custom model object of type
+   * `AppType` into a plain JavaScript object, `DbType` (suitable for writing
+   * directly to the Firestore database). To use `set()` with `merge` and
+   * mergeFields`, `toFirestore()` must be defined with
+   * `PartialWithFieldValue<T>`.
    *
    * The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as
    * {@link (deleteField:1)} to be used as property values.
@@ -96,10 +102,11 @@ export interface FirestoreDataConverter<AppType = DocumentData, DbType extends D
   toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 
   /**
-   * Called by the Firestore SDK to convert a custom model object of type `T`
-   * into a plain JavaScript object (suitable for writing directly to the
-   * Firestore database). Used with {@link (setDoc:1)}, {@link (WriteBatch.set:1)}
-   * and {@link (Transaction.set:1)} with `merge:true` or `mergeFields`.
+   * Called by the Firestore SDK to convert a custom model object of type
+   * `AppType` into a plain JavaScript object, `DbType` (suitable for writing
+   * directly to the Firestore database). Used with {@link (setDoc:1)},
+   * {@link (WriteBatch.set:1)} and {@link (Transaction.set:1)} with
+   * `merge:true` or `mergeFields`.
    *
    * The `PartialWithFieldValue<T>` type extends `Partial<T>` to allow
    * FieldValues such as {@link (arrayUnion:1)} to be used as property values.
@@ -113,7 +120,8 @@ export interface FirestoreDataConverter<AppType = DocumentData, DbType extends D
 
   /**
    * Called by the Firestore SDK to convert Firestore data into an object of
-   * type T. You can access your data by calling: `snapshot.data(options)`.
+   * type `AppType`. You can access your data by calling:
+   * `snapshot.data(options)`.
    *
    * @param snapshot - A `QueryDocumentSnapshot` containing your data and metadata.
    * @param options - The `SnapshotOptions` from the initial call to `data()`.
@@ -199,7 +207,12 @@ export type DocumentChangeType = 'added' | 'removed' | 'modified';
  * A `DocumentChange` represents a change to the documents matching a query.
  * It contains the document affected and the type of change that occurred.
  */
-export interface DocumentChange<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export interface DocumentChange<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /** The type of change ('added', 'modified', or 'removed'). */
   readonly type: DocumentChangeType;
 
@@ -231,7 +244,12 @@ export interface DocumentChange<AppType = DocumentData, DbType extends DocumentD
  * access will return 'undefined'. You can use the `exists()` method to
  * explicitly verify a document's existence.
  */
-export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends LiteDocumentSnapshot<AppType, DbType> {
+export class DocumentSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> extends LiteDocumentSnapshot<AppType, DbType> {
   private readonly _firestoreImpl: Firestore;
 
   /**
@@ -343,7 +361,12 @@ export class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentDat
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> {
+export class QueryDocumentSnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> extends DocumentSnapshot<AppType, DbType> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *
@@ -369,7 +392,12 @@ export class QueryDocumentSnapshot<AppType = DocumentData, DbType extends Docume
  * number of documents can be determined via the `empty` and `size`
  * properties.
  */
-export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> {
+export class QuerySnapshot<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+> {
   /**
    * Metadata about this snapshot, concerning its source and if it has local
    * modifications.
@@ -454,7 +482,9 @@ export class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData =
    * changes (i.e. only `DocumentSnapshot.metadata` changed) should trigger
    * snapshot events.
    */
-  docChanges(options: SnapshotListenOptions = {}): Array<DocumentChange<AppType, DbType>> {
+  docChanges(
+    options: SnapshotListenOptions = {}
+  ): Array<DocumentChange<AppType, DbType>> {
     const includeMetadataChanges = !!options.includeMetadataChanges;
 
     if (includeMetadataChanges && this._snapshot.excludesMetadataChanges) {
@@ -583,7 +613,15 @@ export function resultChangeType(type: ChangeType): DocumentChangeType {
  * @param right - A snapshot to compare.
  * @returns true if the snapshots are equal.
  */
-export function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean {
+export function snapshotEqual<
+  AppType = DocumentData,
+  DbType extends DocumentData = AppType extends DocumentData
+    ? AppType
+    : DocumentData
+>(
+  left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>,
+  right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>
+): boolean {
   if (left instanceof DocumentSnapshot && right instanceof DocumentSnapshot) {
     return (
       left._firestore === right._firestore &&
diff --git a/packages/firestore/src/api/transaction.ts b/packages/firestore/src/api/transaction.ts
index 2bb7954d0d2..cac887d1309 100644
--- a/packages/firestore/src/api/transaction.ts
+++ b/packages/firestore/src/api/transaction.ts
@@ -22,7 +22,7 @@ import {
   DEFAULT_TRANSACTION_OPTIONS,
   validateTransactionOptions
 } from '../core/transaction_options';
-import {DocumentData, DocumentReference} from '../lite-api/reference';
+import { DocumentData, DocumentReference } from '../lite-api/reference';
 import { Transaction as LiteTransaction } from '../lite-api/transaction';
 import { validateReference } from '../lite-api/write_batch';
 import { cast } from '../util/input_validation';
@@ -57,8 +57,13 @@ export class Transaction extends LiteTransaction {
    * @param documentRef - A reference to the document to be read.
    * @returns A `DocumentSnapshot` with the read data.
    */
-  get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>> {
-    const ref = validateReference<AppType, DbType>(documentRef, this._firestore);
+  get<AppType, DbType extends DocumentData>(
+    documentRef: DocumentReference<AppType, DbType>
+  ): Promise<DocumentSnapshot<AppType, DbType>> {
+    const ref = validateReference<AppType, DbType>(
+      documentRef,
+      this._firestore
+    );
     const userDataWriter = new ExpUserDataWriter(this._firestore);
     return super
       .get(documentRef)
diff --git a/packages/firestore/src/lite-api/snapshot.ts b/packages/firestore/src/lite-api/snapshot.ts
index 7e95fec8c91..9588ac0a0f0 100644
--- a/packages/firestore/src/lite-api/snapshot.ts
+++ b/packages/firestore/src/lite-api/snapshot.ts
@@ -56,7 +56,7 @@ import { AbstractUserDataWriter } from './user_data_writer';
  *   }
  * }
  *
- * const postConverter = {
+ * const postConverter: FirestoreDataConverter<Post, DocumentData> = {
  *   toFirestore(post: WithFieldValue<Post>): DocumentData {
  *     return {title: post.title, author: post.author};
  *   },

From d075807b1e7428de391bb3bb47297fa37f0048ce Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 14:27:08 -0400
Subject: [PATCH 8/9] yarn docgen devsite

---
 .../firestore_.aggregatequerysnapshot.md      |  10 +-
 .../firestore_.collectionreference.md         |  18 +-
 docs-devsite/firestore_.documentchange.md     |   6 +-
 docs-devsite/firestore_.documentdata.md       |  19 --
 docs-devsite/firestore_.documentreference.md  |  20 +-
 docs-devsite/firestore_.documentsnapshot.md   |  14 +-
 .../firestore_.firestoredataconverter.md      |  36 +--
 docs-devsite/firestore_.md                    | 220 +++++++++---------
 docs-devsite/firestore_.query.md              |  16 +-
 .../firestore_.querydocumentsnapshot.md       |   8 +-
 docs-devsite/firestore_.querysnapshot.md      |  18 +-
 docs-devsite/firestore_.transaction.md        |  32 +--
 docs-devsite/firestore_.writebatch.md         |  26 +--
 .../firestore_lite.aggregatequerysnapshot.md  |  10 +-
 .../firestore_lite.collectionreference.md     |  18 +-
 docs-devsite/firestore_lite.documentdata.md   |  19 --
 .../firestore_lite.documentreference.md       |  20 +-
 .../firestore_lite.documentsnapshot.md        |  14 +-
 .../firestore_lite.firestoredataconverter.md  |  36 +--
 docs-devsite/firestore_lite.md                | 140 +++++------
 docs-devsite/firestore_lite.query.md          |  16 +-
 .../firestore_lite.querydocumentsnapshot.md   |   8 +-
 docs-devsite/firestore_lite.querysnapshot.md  |  14 +-
 docs-devsite/firestore_lite.transaction.md    |  32 +--
 docs-devsite/firestore_lite.writebatch.md     |  26 +--
 25 files changed, 389 insertions(+), 407 deletions(-)
 delete mode 100644 docs-devsite/firestore_.documentdata.md
 delete mode 100644 docs-devsite/firestore_lite.documentdata.md

diff --git a/docs-devsite/firestore_.aggregatequerysnapshot.md b/docs-devsite/firestore_.aggregatequerysnapshot.md
index 1cf63b5db8b..0c0e77f5870 100644
--- a/docs-devsite/firestore_.aggregatequerysnapshot.md
+++ b/docs-devsite/firestore_.aggregatequerysnapshot.md
@@ -15,14 +15,14 @@ The results of executing an aggregation query.
 <b>Signature:</b>
 
 ```typescript
-export declare class AggregateQuerySnapshot<T extends AggregateSpec> 
+export declare class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [query](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshotquery) |  | [Query](./firestore_.query.md#query_class)<!-- -->&lt;unknown&gt; | The underlying query over which the aggregations recorded in this <code>AggregateQuerySnapshot</code> were performed. |
+|  [query](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshotquery) |  | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The underlying query over which the aggregations recorded in this <code>AggregateQuerySnapshot</code> were performed. |
 |  [type](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshottype) |  | (not declared) | A type string to uniquely identify instances of this class. |
 
 ## Methods
@@ -38,7 +38,7 @@ The underlying query over which the aggregations recorded in this `AggregateQuer
 <b>Signature:</b>
 
 ```typescript
-readonly query: Query<unknown>;
+readonly query: Query<AppType, DbType>;
 ```
 
 ## AggregateQuerySnapshot.type
@@ -60,11 +60,11 @@ The keys of the returned object will be the same as those of the `AggregateSpec`
 <b>Signature:</b>
 
 ```typescript
-data(): AggregateSpecData<T>;
+data(): AggregateSpecData<AggregateSpecType>;
 ```
 <b>Returns:</b>
 
-[AggregateSpecData](./firestore_.md#aggregatespecdata)<!-- -->&lt;T&gt;
+[AggregateSpecData](./firestore_.md#aggregatespecdata)<!-- -->&lt;AggregateSpecType&gt;
 
 The results of the aggregations performed over the underlying query.
 
diff --git a/docs-devsite/firestore_.collectionreference.md b/docs-devsite/firestore_.collectionreference.md
index 56c81c6b245..80c60e2fbe8 100644
--- a/docs-devsite/firestore_.collectionreference.md
+++ b/docs-devsite/firestore_.collectionreference.md
@@ -15,16 +15,16 @@ A `CollectionReference` object can be used for adding documents, getting documen
 <b>Signature:</b>
 
 ```typescript
-export declare class CollectionReference<T = DocumentData> extends Query<T> 
+export declare class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> 
 ```
-<b>Extends:</b> [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt;
+<b>Extends:</b> [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
 |  [id](./firestore_.collectionreference.md#collectionreferenceid) |  | string | The collection's identifier. |
-|  [parent](./firestore_.collectionreference.md#collectionreferenceparent) |  | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt; \| null | A reference to the containing <code>DocumentReference</code> if this is a subcollection. If this isn't a subcollection, the reference is null. |
+|  [parent](./firestore_.collectionreference.md#collectionreferenceparent) |  | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt; \| null | A reference to the containing <code>DocumentReference</code> if this is a subcollection. If this isn't a subcollection, the reference is null. |
 |  [path](./firestore_.collectionreference.md#collectionreferencepath) |  | string | A string representing the path of the referenced collection (relative to the root of the database). |
 |  [type](./firestore_.collectionreference.md#collectionreferencetype) |  | (not declared) | The type of this Firestore reference. |
 
@@ -52,7 +52,7 @@ A reference to the containing `DocumentReference` if this is a subcollection. If
 <b>Signature:</b>
 
 ```typescript
-get parent(): DocumentReference<DocumentData> | null;
+get parent(): DocumentReference<DocumentData, DocumentData> | null;
 ```
 
 ## CollectionReference.path
@@ -82,18 +82,18 @@ Applies a custom data converter to this `CollectionReference`<!-- -->, allowing
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): CollectionReference<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): CollectionReference<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;U&gt;
+[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `CollectionReference<U>` that uses the provided converter.
 
@@ -104,7 +104,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): CollectionReference<DocumentData>;
+withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -115,7 +115,7 @@ withConverter(converter: null): CollectionReference<DocumentData>;
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 A `CollectionReference<DocumentData>` that does not use a converter.
 
diff --git a/docs-devsite/firestore_.documentchange.md b/docs-devsite/firestore_.documentchange.md
index afef795956d..1c4f175983e 100644
--- a/docs-devsite/firestore_.documentchange.md
+++ b/docs-devsite/firestore_.documentchange.md
@@ -15,14 +15,14 @@ A `DocumentChange` represents a change to the documents matching a query. It con
 <b>Signature:</b>
 
 ```typescript
-export declare interface DocumentChange<T = DocumentData> 
+export declare interface DocumentChange<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Type | Description |
 |  --- | --- | --- |
-|  [doc](./firestore_.documentchange.md#documentchangedoc) | [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt; | The document affected by this change. |
+|  [doc](./firestore_.documentchange.md#documentchangedoc) | [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt; | The document affected by this change. |
 |  [newIndex](./firestore_.documentchange.md#documentchangenewindex) | number | The index of the changed document in the result set immediately after this <code>DocumentChange</code> (i.e. supposing that all prior <code>DocumentChange</code> objects and the current <code>DocumentChange</code> object have been applied). Is -1 for 'removed' events. |
 |  [oldIndex](./firestore_.documentchange.md#documentchangeoldindex) | number | The index of the changed document in the result set immediately prior to this <code>DocumentChange</code> (i.e. supposing that all prior <code>DocumentChange</code> objects have been applied). Is <code>-1</code> for 'added' events. |
 |  [type](./firestore_.documentchange.md#documentchangetype) | [DocumentChangeType](./firestore_.md#documentchangetype) | The type of change ('added', 'modified', or 'removed'). |
@@ -34,7 +34,7 @@ The document affected by this change.
 <b>Signature:</b>
 
 ```typescript
-readonly doc: QueryDocumentSnapshot<T>;
+readonly doc: QueryDocumentSnapshot<AppType, DbType>;
 ```
 
 ## DocumentChange.newIndex
diff --git a/docs-devsite/firestore_.documentdata.md b/docs-devsite/firestore_.documentdata.md
deleted file mode 100644
index 09b5eb64b48..00000000000
--- a/docs-devsite/firestore_.documentdata.md
+++ /dev/null
@@ -1,19 +0,0 @@
-Project: /docs/reference/js/_project.yaml
-Book: /docs/reference/_book.yaml
-page_type: reference
-
-{% comment %}
-DO NOT EDIT THIS FILE!
-This is generated by the JS SDK team, and any local changes will be
-overwritten. Changes should be made in the source code at
-https://github.com/firebase/firebase-js-sdk
-{% endcomment %}
-
-# DocumentData interface
-Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->) consists of fields mapped to values.
-
-<b>Signature:</b>
-
-```typescript
-export declare interface DocumentData 
-```
diff --git a/docs-devsite/firestore_.documentreference.md b/docs-devsite/firestore_.documentreference.md
index 16dff93b9c8..da8b3168ef7 100644
--- a/docs-devsite/firestore_.documentreference.md
+++ b/docs-devsite/firestore_.documentreference.md
@@ -15,17 +15,17 @@ A `DocumentReference` refers to a document location in a Firestore database and
 <b>Signature:</b>
 
 ```typescript
-export declare class DocumentReference<T = DocumentData> 
+export declare class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [converter](./firestore_.documentreference.md#documentreferenceconverter) |  | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;T&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
+|  [converter](./firestore_.documentreference.md#documentreferenceconverter) |  | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;AppType, DbType&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
 |  [firestore](./firestore_.documentreference.md#documentreferencefirestore) |  | [Firestore](./firestore_.firestore.md#firestore_class) | The [Firestore](./firestore_.firestore.md#firestore_class) instance the document is in. This is useful for performing transactions, for example. |
 |  [id](./firestore_.documentreference.md#documentreferenceid) |  | string | The document's identifier within its collection. |
-|  [parent](./firestore_.documentreference.md#documentreferenceparent) |  | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | The collection this <code>DocumentReference</code> belongs to. |
+|  [parent](./firestore_.documentreference.md#documentreferenceparent) |  | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | The collection this <code>DocumentReference</code> belongs to. |
 |  [path](./firestore_.documentreference.md#documentreferencepath) |  | string | A string representing the path of the referenced document (relative to the root of the database). |
 |  [type](./firestore_.documentreference.md#documentreferencetype) |  | (not declared) | The type of this Firestore reference. |
 
@@ -43,7 +43,7 @@ If provided, the `FirestoreDataConverter` associated with this instance.
 <b>Signature:</b>
 
 ```typescript
-readonly converter: FirestoreDataConverter<T> | null;
+readonly converter: FirestoreDataConverter<AppType, DbType> | null;
 ```
 
 ## DocumentReference.firestore
@@ -73,7 +73,7 @@ The collection this `DocumentReference` belongs to.
 <b>Signature:</b>
 
 ```typescript
-get parent(): CollectionReference<T>;
+get parent(): CollectionReference<AppType, DbType>;
 ```
 
 ## DocumentReference.path
@@ -103,18 +103,18 @@ Applies a custom data converter to this `DocumentReference`<!-- -->, allowing yo
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): DocumentReference<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;U&gt;
+[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `DocumentReference<U>` that uses the provided converter.
 
@@ -125,7 +125,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): DocumentReference<DocumentData>;
+withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -136,7 +136,7 @@ withConverter(converter: null): DocumentReference<DocumentData>;
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 A `DocumentReference<DocumentData>` that does not use a converter.
 
diff --git a/docs-devsite/firestore_.documentsnapshot.md b/docs-devsite/firestore_.documentsnapshot.md
index 3ac2ec7dcb2..582f6f8699d 100644
--- a/docs-devsite/firestore_.documentsnapshot.md
+++ b/docs-devsite/firestore_.documentsnapshot.md
@@ -17,7 +17,7 @@ For a `DocumentSnapshot` that points to a non-existing document, any data access
 <b>Signature:</b>
 
 ```typescript
-export declare class DocumentSnapshot<T = DocumentData> 
+export declare class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Constructors
@@ -32,7 +32,7 @@ export declare class DocumentSnapshot<T = DocumentData>
 |  --- | --- | --- | --- |
 |  [id](./firestore_.documentsnapshot.md#documentsnapshotid) |  | string | Property of the <code>DocumentSnapshot</code> that provides the document's ID. |
 |  [metadata](./firestore_.documentsnapshot.md#documentsnapshotmetadata) |  | [SnapshotMetadata](./firestore_.snapshotmetadata.md#snapshotmetadata_class) | Metadata about the <code>DocumentSnapshot</code>, including information about its source and local modifications. |
-|  [ref](./firestore_.documentsnapshot.md#documentsnapshotref) |  | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | The <code>DocumentReference</code> for the document included in the <code>DocumentSnapshot</code>. |
+|  [ref](./firestore_.documentsnapshot.md#documentsnapshotref) |  | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | The <code>DocumentReference</code> for the document included in the <code>DocumentSnapshot</code>. |
 
 ## Methods
 
@@ -79,7 +79,7 @@ The `DocumentReference` for the document included in the `DocumentSnapshot`<!--
 <b>Signature:</b>
 
 ```typescript
-get ref(): DocumentReference<T>;
+get ref(): DocumentReference<AppType, DbType>;
 ```
 
 ## DocumentSnapshot.data()
@@ -91,7 +91,7 @@ By default, `serverTimestamp()` values that have not yet been set to their final
 <b>Signature:</b>
 
 ```typescript
-data(options?: SnapshotOptions): T | undefined;
+data(options?: SnapshotOptions): AppType | undefined;
 ```
 
 ### Parameters
@@ -102,7 +102,7 @@ data(options?: SnapshotOptions): T | undefined;
 
 <b>Returns:</b>
 
-T \| undefined
+AppType \| undefined
 
 An `Object` containing all fields in the document or `undefined` if the document doesn't exist.
 
@@ -113,11 +113,11 @@ Returns whether or not the data exists. True if the document exists.
 <b>Signature:</b>
 
 ```typescript
-exists(): this is QueryDocumentSnapshot<T>;
+exists(): this is QueryDocumentSnapshot<AppType, DbType>;
 ```
 <b>Returns:</b>
 
-this is [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;
+this is [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## DocumentSnapshot.get()
 
diff --git a/docs-devsite/firestore_.firestoredataconverter.md b/docs-devsite/firestore_.firestoredataconverter.md
index f7d80ac4a13..0a6199ae53c 100644
--- a/docs-devsite/firestore_.firestoredataconverter.md
+++ b/docs-devsite/firestore_.firestoredataconverter.md
@@ -10,89 +10,89 @@ https://github.com/firebase/firebase-js-sdk
 {% endcomment %}
 
 # FirestoreDataConverter interface
-Converter used by `withConverter()` to transform user objects of type `T` into Firestore data.
+Converter used by `withConverter()` to transform user objects of type `AppType` into Firestore data.
 
 Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore.
 
 <b>Signature:</b>
 
 ```typescript
-export declare interface FirestoreDataConverter<T> 
+export declare interface FirestoreDataConverter<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Methods
 
 |  Method | Description |
 |  --- | --- |
-|  [fromFirestore(snapshot, options)](./firestore_.firestoredataconverter.md#firestoredataconverterfromfirestore) | Called by the Firestore SDK to convert Firestore data into an object of type T. You can access your data by calling: <code>snapshot.data(options)</code>. |
-|  [toFirestore(modelObject)](./firestore_.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>T</code> into a plain JavaScript object (suitable for writing directly to the Firestore database). To use <code>set()</code> with <code>merge</code> and <code>mergeFields</code>, <code>toFirestore()</code> must be defined with <code>PartialWithFieldValue&lt;T&gt;</code>.<!-- -->The <code>WithFieldValue&lt;T&gt;</code> type extends <code>T</code> to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values. |
-|  [toFirestore(modelObject, options)](./firestore_.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>T</code> into a plain JavaScript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_.md#setdoc)<!-- -->,  and  with <code>merge:true</code> or <code>mergeFields</code>.<!-- -->The <code>PartialWithFieldValue&lt;T&gt;</code> type extends <code>Partial&lt;T&gt;</code> to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested <code>Partial</code> by allowing nested fields to be omitted. |
+|  [fromFirestore(snapshot, options)](./firestore_.firestoredataconverter.md#firestoredataconverterfromfirestore) | Called by the Firestore SDK to convert Firestore data into an object of type <code>AppType</code>. You can access your data by calling: <code>snapshot.data(options)</code>. |
+|  [toFirestore(modelObject)](./firestore_.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>AppType</code> into a plain JavaScript object, <code>DbType</code> (suitable for writing directly to the Firestore database). To use <code>set()</code> with <code>merge</code> and mergeFields<code>, </code>toFirestore()<code> must be defined with </code>PartialWithFieldValue<T>\`<!-- -->.<!-- -->The <code>WithFieldValue&lt;T&gt;</code> type extends <code>T</code> to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values. |
+|  [toFirestore(modelObject, options)](./firestore_.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>AppType</code> into a plain JavaScript object, <code>DbType</code> (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_.md#setdoc)<!-- -->,  and  with <code>merge:true</code> or <code>mergeFields</code>.<!-- -->The <code>PartialWithFieldValue&lt;T&gt;</code> type extends <code>Partial&lt;T&gt;</code> to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested <code>Partial</code> by allowing nested fields to be omitted. |
 
 ## FirestoreDataConverter.fromFirestore()
 
-Called by the Firestore SDK to convert Firestore data into an object of type T. You can access your data by calling: `snapshot.data(options)`<!-- -->.
+Called by the Firestore SDK to convert Firestore data into an object of type `AppType`<!-- -->. You can access your data by calling: `snapshot.data(options)`<!-- -->.
 
 <b>Signature:</b>
 
 ```typescript
-fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>, options?: SnapshotOptions): T;
+fromFirestore(snapshot: QueryDocumentSnapshot<DbType, DbType>, options?: SnapshotOptions): AppType;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  snapshot | [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt; | A <code>QueryDocumentSnapshot</code> containing your data and metadata. |
+|  snapshot | [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;DbType, DbType&gt; | A <code>QueryDocumentSnapshot</code> containing your data and metadata. |
 |  options | [SnapshotOptions](./firestore_.snapshotoptions.md#snapshotoptions_interface) | The <code>SnapshotOptions</code> from the initial call to <code>data()</code>. |
 
 <b>Returns:</b>
 
-T
+AppType
 
 ## FirestoreDataConverter.toFirestore()
 
-Called by the Firestore SDK to convert a custom model object of type `T` into a plain JavaScript object (suitable for writing directly to the Firestore database). To use `set()` with `merge` and `mergeFields`<!-- -->, `toFirestore()` must be defined with `PartialWithFieldValue<T>`<!-- -->.
+Called by the Firestore SDK to convert a custom model object of type `AppType` into a plain JavaScript object, `DbType` (suitable for writing directly to the Firestore database). To use `set()` with `merge` and mergeFields`, `<!-- -->toFirestore()` must be defined with `<!-- -->PartialWithFieldValue<T>\`<!-- -->.
 
 The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values.
 
 <b>Signature:</b>
 
 ```typescript
-toFirestore(modelObject: WithFieldValue<T>): DocumentData;
+toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  modelObject | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;T&gt; |  |
+|  modelObject | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;AppType&gt; |  |
 
 <b>Returns:</b>
 
-[DocumentData](./firestore_.documentdata.md#documentdata_interface)
+[WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;DbType&gt;
 
 ## FirestoreDataConverter.toFirestore()
 
-Called by the Firestore SDK to convert a custom model object of type `T` into a plain JavaScript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_.md#setdoc)<!-- -->,  and  with `merge:true` or `mergeFields`<!-- -->.
+Called by the Firestore SDK to convert a custom model object of type `AppType` into a plain JavaScript object, `DbType` (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_.md#setdoc)<!-- -->,  and  with `merge:true` or `mergeFields`<!-- -->.
 
 The `PartialWithFieldValue<T>` type extends `Partial<T>` to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested `Partial` by allowing nested fields to be omitted.
 
 <b>Signature:</b>
 
 ```typescript
-toFirestore(modelObject: PartialWithFieldValue<T>, options: SetOptions): DocumentData;
+toFirestore(modelObject: PartialWithFieldValue<AppType>, options: SetOptions): PartialWithFieldValue<DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  modelObject | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;T&gt; |  |
+|  modelObject | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; |  |
 |  options | [SetOptions](./firestore_.md#setoptions) |  |
 
 <b>Returns:</b>
 
-[DocumentData](./firestore_.documentdata.md#documentdata_interface)
+[PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;DbType&gt;
 
 ### Example
 
@@ -106,7 +106,7 @@ class Post {
   }
 }
 
-const postConverter = {
+const postConverter: FirestoreDataConverter<Post, DocumentData> = {
   toFirestore(post: WithFieldValue<Post>): DocumentData {
     return {title: post.title, author: post.author};
   },
diff --git a/docs-devsite/firestore_.md b/docs-devsite/firestore_.md
index 3fc6c253769..277da95de94 100644
--- a/docs-devsite/firestore_.md
+++ b/docs-devsite/firestore_.md
@@ -148,8 +148,7 @@ https://github.com/firebase/firebase-js-sdk
 |  --- | --- |
 |  [AggregateSpec](./firestore_.aggregatespec.md#aggregatespec_interface) | Specifies a set of aggregations and their aliases. |
 |  [DocumentChange](./firestore_.documentchange.md#documentchange_interface) | A <code>DocumentChange</code> represents a change to the documents matching a query. It contains the document affected and the type of change that occurred. |
-|  [DocumentData](./firestore_.documentdata.md#documentdata_interface) | Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->) consists of fields mapped to values. |
-|  [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface) | Converter used by <code>withConverter()</code> to transform user objects of type <code>T</code> into Firestore data.<!-- -->Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore. |
+|  [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface) | Converter used by <code>withConverter()</code> to transform user objects of type <code>AppType</code> into Firestore data.<!-- -->Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore. |
 |  [FirestoreSettings](./firestore_.firestoresettings.md#firestoresettings_interface) | Specifies custom configurations for your Cloud Firestore instance. You must set these before invoking any other methods. |
 |  [Index](./firestore_.index.md#index_interface) | <b><i>(BETA)</i></b> The SDK definition of a Firestore index. |
 |  [IndexConfiguration](./firestore_.indexconfiguration.md#indexconfiguration_interface) | <b><i>(BETA)</i></b> A list of Firestore indexes to speed up local query execution.<!-- -->See [JSON Format](https://firebase.google.com/docs/reference/firestore/indexes/#json_format) for a description of the format of the index definition. |
@@ -185,6 +184,7 @@ https://github.com/firebase/firebase-js-sdk
 |  [AggregateSpecData](./firestore_.md#aggregatespecdata) | A type whose keys are taken from an <code>AggregateSpec</code>, and whose values are the result of the aggregation performed by the corresponding <code>AggregateField</code> from the input <code>AggregateSpec</code>. |
 |  [ChildUpdateFields](./firestore_.md#childupdatefields) | Helper for calculating the nested fields for a given type T1. This is needed to distribute union types such as <code>undefined &#124; {...}</code> (happens for optional props) or <code>{a: A} &#124; {b: B}</code>.<!-- -->In this use case, <code>V</code> is used to distribute the union types of <code>T[K]</code> on <code>Record</code>, since <code>T[K]</code> is evaluated as an expression and not distributed.<!-- -->See https://www.typescriptlang.org/docs/handbook/advanced-types.html\#distributive-conditional-types |
 |  [DocumentChangeType](./firestore_.md#documentchangetype) | The type of a <code>DocumentChange</code> may be 'added', 'removed', or 'modified'. |
+|  [DocumentData](./firestore_.md#documentdata) | Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->). Must be an object with string keys. |
 |  [FirestoreErrorCode](./firestore_.md#firestoreerrorcode) | The set of Firestore status codes. The codes are the same at the ones exposed by gRPC here: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md<!-- -->Possible values: - 'cancelled': The operation was cancelled (typically by the caller). - 'unknown': Unknown error or an error from a different error domain. - 'invalid-argument': Client specified an invalid argument. Note that this differs from 'failed-precondition'. 'invalid-argument' indicates arguments that are problematic regardless of the state of the system (e.g. an invalid field name). - 'deadline-exceeded': Deadline expired before operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. For example, a successful response from a server could have been delayed long enough for the deadline to expire. - 'not-found': Some requested document was not found. - 'already-exists': Some document that we attempted to create already exists. - 'permission-denied': The caller does not have permission to execute the specified operation. - 'resource-exhausted': Some resource has been exhausted, perhaps a per-user quota, or perhaps the entire file system is out of space. - 'failed-precondition': Operation was rejected because the system is not in a state required for the operation's execution. - 'aborted': The operation was aborted, typically due to a concurrency issue like transaction aborts, etc. - 'out-of-range': Operation was attempted past the valid range. - 'unimplemented': Operation is not implemented or not supported/enabled. - 'internal': Internal errors. Means some invariants expected by underlying system has been broken. If you see one of these errors, something is very broken. - 'unavailable': The service is currently unavailable. This is most likely a transient condition and may be corrected by retrying with a backoff. - 'data-loss': Unrecoverable data loss or corruption. - 'unauthenticated': The request does not have valid authentication credentials for the operation. |
 |  [FirestoreLocalCache](./firestore_.md#firestorelocalcache) | Union type from all supported SDK cache layer. |
 |  [MemoryGarbageCollector](./firestore_.md#memorygarbagecollector) | Union type from all support gabage collectors for memory local cache. |
@@ -282,7 +282,7 @@ Gets a `CollectionReference` instance that refers to the collection at the speci
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -295,7 +295,7 @@ export declare function collection(firestore: Firestore, path: string, ...pathSe
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -310,7 +310,7 @@ Creates and returns a new `Query` instance that includes all documents in the da
 <b>Signature:</b>
 
 ```typescript
-export declare function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData>;
+export declare function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -322,7 +322,7 @@ export declare function collectionGroup(firestore: Firestore, collectionId: stri
 
 <b>Returns:</b>
 
-[Query](./firestore_.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[Query](./firestore_.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The created `Query`<!-- -->.
 
@@ -382,7 +382,7 @@ Gets a `DocumentReference` instance that refers to the document at the specified
 <b>Signature:</b>
 
 ```typescript
-export declare function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export declare function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -395,7 +395,7 @@ export declare function doc(firestore: Firestore, path: string, ...pathSegments:
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The `DocumentReference` instance.
 
@@ -1042,15 +1042,15 @@ Two `AggregateQuerySnapshot` instances are considered "equal" if they have under
 <b>Signature:</b>
 
 ```typescript
-export declare function aggregateQuerySnapshotEqual<T extends AggregateSpec>(left: AggregateQuerySnapshot<T>, right: AggregateQuerySnapshot<T>): boolean;
+export declare function aggregateQuerySnapshotEqual<AggregateSpecType extends AggregateSpec>(left: AggregateQuerySnapshot<AggregateSpecType>, right: AggregateQuerySnapshot<AggregateSpecType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;T&gt; | The first <code>AggregateQuerySnapshot</code> to compare. |
-|  right | [AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;T&gt; | The second <code>AggregateQuerySnapshot</code> to compare. |
+|  left | [AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;AggregateSpecType&gt; | The first <code>AggregateQuerySnapshot</code> to compare. |
+|  right | [AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;AggregateSpecType&gt; | The second <code>AggregateQuerySnapshot</code> to compare. |
 
 <b>Returns:</b>
 
@@ -1065,15 +1065,15 @@ Returns true if the provided queries point to the same collection and apply the
 <b>Signature:</b>
 
 ```typescript
-export declare function queryEqual<T>(left: Query<T>, right: Query<T>): boolean;
+export declare function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | A <code>Query</code> to compare. |
-|  right | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | A <code>Query</code> to compare. |
+|  left | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | A <code>Query</code> to compare. |
+|  right | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | A <code>Query</code> to compare. |
 
 <b>Returns:</b>
 
@@ -1088,15 +1088,15 @@ Returns true if the provided references are equal.
 <b>Signature:</b>
 
 ```typescript
-export declare function refEqual<T>(left: DocumentReference<T> | CollectionReference<T>, right: DocumentReference<T> | CollectionReference<T>): boolean;
+export declare function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>, right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; \| [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to compare. |
-|  right | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; \| [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to compare. |
+|  left | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; \| [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to compare. |
+|  right | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; \| [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to compare. |
 
 <b>Returns:</b>
 
@@ -1111,15 +1111,15 @@ Returns true if the provided snapshots are equal.
 <b>Signature:</b>
 
 ```typescript
-export declare function snapshotEqual<T>(left: DocumentSnapshot<T> | QuerySnapshot<T>, right: DocumentSnapshot<T> | QuerySnapshot<T>): boolean;
+export declare function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt; \| [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt; | A snapshot to compare. |
-|  right | [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt; \| [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt; | A snapshot to compare. |
+|  left | [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt; \| [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt; | A snapshot to compare. |
+|  right | [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt; \| [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt; | A snapshot to compare. |
 
 <b>Returns:</b>
 
@@ -1230,20 +1230,20 @@ The result received from the server is presented, unaltered, without considering
 <b>Signature:</b>
 
 ```typescript
-export declare function getCountFromServer(query: Query<unknown>): Promise<AggregateQuerySnapshot<{
+export declare function getCountFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{
     count: AggregateField<number>;
-}>>;
+}, AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;unknown&gt; | The query whose result set size to calculate. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query whose result set size to calculate. |
 
 <b>Returns:</b>
 
-Promise&lt;[AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;{ count: [AggregateField](./firestore_.aggregatefield.md#aggregatefield_class)<!-- -->&lt;number&gt;; }&gt;&gt;
+Promise&lt;[AggregateQuerySnapshot](./firestore_.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;{ count: [AggregateField](./firestore_.aggregatefield.md#aggregatefield_class)<!-- -->&lt;number&gt;; }, AppType, DbType&gt;&gt;
 
 A Promise that will be resolved with the count; the count can be retrieved from `snapshot.data().count`<!-- -->, where `snapshot` is the `AggregateQuerySnapshot` to which the returned Promise resolves.
 
@@ -1256,18 +1256,18 @@ Note: `getDocs()` attempts to provide up-to-date data when possible by waiting f
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export declare function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; |  |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; |  |
 
 <b>Returns:</b>
 
-Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` that will be resolved with the results of the query.
 
@@ -1278,18 +1278,18 @@ Executes the query and returns the results as a `QuerySnapshot` from cache. Retu
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocsFromCache<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export declare function getDocsFromCache<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; |  |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; |  |
 
 <b>Returns:</b>
 
-Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` that will be resolved with the results of the query.
 
@@ -1300,18 +1300,18 @@ Executes the query and returns the results as a `QuerySnapshot` from the server.
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocsFromServer<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export declare function getDocsFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; |  |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; |  |
 
 <b>Returns:</b>
 
-Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` that will be resolved with the results of the query.
 
@@ -1324,8 +1324,8 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(query: Query<T>, observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, observer: {
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
@@ -1335,8 +1335,8 @@ export declare function onSnapshot<T>(query: Query<T>, observer: {
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The query to listen to. |
-|  observer | { next?: (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query to listen to. |
+|  observer | { next?: (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
 
 <b>Returns:</b>
 
@@ -1353,8 +1353,8 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(query: Query<T>, options: SnapshotListenOptions, observer: {
-    next?: (snapshot: QuerySnapshot<T>) => void;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, options: SnapshotListenOptions, observer: {
+    next?: (snapshot: QuerySnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
@@ -1364,9 +1364,9 @@ export declare function onSnapshot<T>(query: Query<T>, options: SnapshotListenOp
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The query to listen to. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query to listen to. |
 |  options | [SnapshotListenOptions](./firestore_.snapshotlistenoptions.md#snapshotlistenoptions_interface) | Options controlling the listen behavior. |
-|  observer | { next?: (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
+|  observer | { next?: (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
 
 <b>Returns:</b>
 
@@ -1383,15 +1383,15 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(query: Query<T>, onNext: (snapshot: QuerySnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The query to listen to. |
-|  onNext | (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called every time a new <code>QuerySnapshot</code> is available. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query to listen to. |
+|  onNext | (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called every time a new <code>QuerySnapshot</code> is available. |
 |  onError | (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void | A callback to be called if the listen fails or is cancelled. No further callbacks will occur. |
 |  onCompletion | () =&gt; void | Can be provided, but will not be called since streams are never ending. |
 
@@ -1410,16 +1410,16 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(query: Query<T>, options: SnapshotListenOptions, onNext: (snapshot: QuerySnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, options: SnapshotListenOptions, onNext: (snapshot: QuerySnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The query to listen to. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query to listen to. |
 |  options | [SnapshotListenOptions](./firestore_.snapshotlistenoptions.md#snapshotlistenoptions_interface) | Options controlling the listen behavior. |
-|  onNext | (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called every time a new <code>QuerySnapshot</code> is available. |
+|  onNext | (snapshot: [QuerySnapshot](./firestore_.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called every time a new <code>QuerySnapshot</code> is available. |
 |  onError | (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void | A callback to be called if the listen fails or is cancelled. No further callbacks will occur. |
 |  onCompletion | () =&gt; void | Can be provided, but will not be called since streams are never ending. |
 
@@ -1436,20 +1436,20 @@ Creates a new immutable instance of [Query](./firestore_.query.md#query_class) t
 <b>Signature:</b>
 
 ```typescript
-export declare function query<T>(query: Query<T>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<T>;
+export declare function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
 |  compositeFilter | [QueryCompositeFilterConstraint](./firestore_.querycompositefilterconstraint.md#querycompositefilterconstraint_class) | The [QueryCompositeFilterConstraint](./firestore_.querycompositefilterconstraint.md#querycompositefilterconstraint_class) to apply. Create [QueryCompositeFilterConstraint](./firestore_.querycompositefilterconstraint.md#querycompositefilterconstraint_class) using [and()](./firestore_.md#and) or [or()](./firestore_.md#or)<!-- -->. |
 |  queryConstraints | [QueryNonFilterConstraint](./firestore_.md#querynonfilterconstraint)<!-- -->\[\] | Additional [QueryNonFilterConstraint](./firestore_.md#querynonfilterconstraint)<!-- -->s to apply (e.g. [orderBy()](./firestore_.md#orderby)<!-- -->, [limit()](./firestore_.md#limit)<!-- -->). |
 
 <b>Returns:</b>
 
-[Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt;
+[Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Exceptions
 
@@ -1462,19 +1462,19 @@ Creates a new immutable instance of [Query](./firestore_.query.md#query_class) t
 <b>Signature:</b>
 
 ```typescript
-export declare function query<T>(query: Query<T>, ...queryConstraints: QueryConstraint[]): Query<T>;
+export declare function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, ...queryConstraints: QueryConstraint[]): Query<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
+|  query | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
 |  queryConstraints | [QueryConstraint](./firestore_.queryconstraint.md#queryconstraint_class)<!-- -->\[\] | The list of [QueryConstraint](./firestore_.queryconstraint.md#queryconstraint_class)<!-- -->s to apply. |
 
 <b>Returns:</b>
 
-[Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt;
+[Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Exceptions
 
@@ -1531,19 +1531,19 @@ Add a new document to specified `CollectionReference` with the given data, assig
 <b>Signature:</b>
 
 ```typescript
-export declare function addDoc<T>(reference: CollectionReference<T>, data: WithFieldValue<T>): Promise<DocumentReference<T>>;
+export declare function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<DocumentReference<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to the collection to add this document to. |
-|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;T&gt; | An Object containing the data for the new document. |
+|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the collection to add this document to. |
+|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An Object containing the data for the new document. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` resolved with a `DocumentReference` pointing to the newly created document after it has been written to the backend (Note that it won't resolve while you're offline).
 
@@ -1554,20 +1554,20 @@ Gets a `CollectionReference` instance that refers to a subcollection of `referen
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(reference: CollectionReference<unknown>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;unknown&gt; | A reference to a collection. |
+|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a collection. |
 |  path | string | A slash-separated path to a collection. |
 |  pathSegments | string\[\] | Additional path segments to apply relative to the first argument. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -1582,20 +1582,20 @@ Gets a `CollectionReference` instance that refers to a subcollection of `referen
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(reference: DocumentReference, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class) | A reference to a Firestore document. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a Firestore document. |
 |  path | string | A slash-separated path to a collection. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -1610,14 +1610,14 @@ Deletes the document referred to by the specified `DocumentReference`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-export declare function deleteDoc(reference: DocumentReference<unknown>): Promise<void>;
+export declare function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to delete. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to delete. |
 
 <b>Returns:</b>
 
@@ -1632,20 +1632,20 @@ Gets a `DocumentReference` instance that refers to a document within `reference`
 <b>Signature:</b>
 
 ```typescript
-export declare function doc<T>(reference: CollectionReference<T>, path?: string, ...pathSegments: string[]): DocumentReference<T>;
+export declare function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path?: string, ...pathSegments: string[]): DocumentReference<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to a collection. |
+|  reference | [CollectionReference](./firestore_.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a collection. |
 |  path | string | A slash-separated path to a document. Has to be omitted to use auto-genrated IDs. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt;
+[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt;
 
 The `DocumentReference` instance.
 
@@ -1660,20 +1660,20 @@ Gets a `DocumentReference` instance that refers to a document within `reference`
 <b>Signature:</b>
 
 ```typescript
-export declare function doc(reference: DocumentReference<unknown>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export declare function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to a Firestore document. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a Firestore document. |
 |  path | string | A slash-separated path to a document. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 The `DocumentReference` instance.
 
@@ -1690,18 +1690,18 @@ Note: `getDoc()` attempts to provide up-to-date data when possible by waiting fo
 <b>Signature:</b>
 
 ```typescript
-export declare function getDoc<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export declare function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | The reference of the document to fetch. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | The reference of the document to fetch. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A Promise resolved with a `DocumentSnapshot` containing the current document contents.
 
@@ -1712,18 +1712,18 @@ Reads the document referred to by this `DocumentReference` from cache. Returns a
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocFromCache<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export declare function getDocFromCache<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; |  |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; |  |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` resolved with a `DocumentSnapshot` containing the current document contents.
 
@@ -1734,18 +1734,18 @@ Reads the document referred to by this `DocumentReference` from the server. Retu
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocFromServer<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export declare function getDocFromServer<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; |  |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; |  |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` resolved with a `DocumentSnapshot` containing the current document contents.
 
@@ -1758,8 +1758,8 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(reference: DocumentReference<T>, observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, observer: {
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
@@ -1769,8 +1769,8 @@ export declare function onSnapshot<T>(reference: DocumentReference<T>, observer:
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to listen to. |
-|  observer | { next?: (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to listen to. |
+|  observer | { next?: (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
 
 <b>Returns:</b>
 
@@ -1787,8 +1787,8 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(reference: DocumentReference<T>, options: SnapshotListenOptions, observer: {
-    next?: (snapshot: DocumentSnapshot<T>) => void;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, options: SnapshotListenOptions, observer: {
+    next?: (snapshot: DocumentSnapshot<AppType, DbType>) => void;
     error?: (error: FirestoreError) => void;
     complete?: () => void;
 }): Unsubscribe;
@@ -1798,9 +1798,9 @@ export declare function onSnapshot<T>(reference: DocumentReference<T>, options:
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to listen to. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to listen to. |
 |  options | [SnapshotListenOptions](./firestore_.snapshotlistenoptions.md#snapshotlistenoptions_interface) | Options controlling the listen behavior. |
-|  observer | { next?: (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
+|  observer | { next?: (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void; error?: (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void; complete?: () =&gt; void; } | A single object containing <code>next</code> and <code>error</code> callbacks. |
 
 <b>Returns:</b>
 
@@ -1817,15 +1817,15 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(reference: DocumentReference<T>, onNext: (snapshot: DocumentSnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to listen to. |
-|  onNext | (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called every time a new <code>DocumentSnapshot</code> is available. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to listen to. |
+|  onNext | (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called every time a new <code>DocumentSnapshot</code> is available. |
 |  onError | (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void | A callback to be called if the listen fails or is cancelled. No further callbacks will occur. |
 |  onCompletion | () =&gt; void | Can be provided, but will not be called since streams are never ending. |
 
@@ -1844,16 +1844,16 @@ NOTE: Although an `onCompletion` callback can be provided, it will never be call
 <b>Signature:</b>
 
 ```typescript
-export declare function onSnapshot<T>(reference: DocumentReference<T>, options: SnapshotListenOptions, onNext: (snapshot: DocumentSnapshot<T>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
+export declare function onSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, options: SnapshotListenOptions, onNext: (snapshot: DocumentSnapshot<AppType, DbType>) => void, onError?: (error: FirestoreError) => void, onCompletion?: () => void): Unsubscribe;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to listen to. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to listen to. |
 |  options | [SnapshotListenOptions](./firestore_.snapshotlistenoptions.md#snapshotlistenoptions_interface) | Options controlling the listen behavior. |
-|  onNext | (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called every time a new <code>DocumentSnapshot</code> is available. |
+|  onNext | (snapshot: [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called every time a new <code>DocumentSnapshot</code> is available. |
 |  onError | (error: [FirestoreError](./firestore_.firestoreerror.md#firestoreerror_class)<!-- -->) =&gt; void | A callback to be called if the listen fails or is cancelled. No further callbacks will occur. |
 |  onCompletion | () =&gt; void | Can be provided, but will not be called since streams are never ending. |
 
@@ -1870,15 +1870,15 @@ Writes to the document referred to by this `DocumentReference`<!-- -->. If the d
 <b>Signature:</b>
 
 ```typescript
-export declare function setDoc<T>(reference: DocumentReference<T>, data: WithFieldValue<T>): Promise<void>;
+export declare function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to write. |
-|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;T&gt; | A map of the fields and values for the document. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to write. |
+|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;AppType&gt; | A map of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -1893,15 +1893,15 @@ Writes to the document referred to by the specified `DocumentReference`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-export declare function setDoc<T>(reference: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): Promise<void>;
+export declare function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to write. |
-|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | A map of the fields and values for the document. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to write. |
+|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | A map of the fields and values for the document. |
 |  options | [SetOptions](./firestore_.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -1917,15 +1917,15 @@ Updates fields in the document referred to by the specified `DocumentReference`<
 <b>Signature:</b>
 
 ```typescript
-export declare function updateDoc<T>(reference: DocumentReference<T>, data: UpdateData<T>): Promise<void>;
+export declare function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to update. |
-|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to update. |
+|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -1942,14 +1942,14 @@ Nested fields can be updated by providing dot-separated field path strings or by
 <b>Signature:</b>
 
 ```typescript
-export declare function updateDoc(reference: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
+export declare function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to update. |
+|  reference | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to update. |
 |  field | string \| [FieldPath](./firestore_.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key value pairs. |
@@ -2200,6 +2200,16 @@ The type of a `DocumentChange` may be 'added', 'removed', or 'modified'.
 export declare type DocumentChangeType = 'added' | 'removed' | 'modified';
 ```
 
+## DocumentData
+
+Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->). Must be an object with string keys.
+
+<b>Signature:</b>
+
+```typescript
+export declare type DocumentData = Record<string, any>;
+```
+
 ## FirestoreErrorCode
 
 The set of Firestore status codes. The codes are the same at the ones exposed by gRPC here: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
diff --git a/docs-devsite/firestore_.query.md b/docs-devsite/firestore_.query.md
index 1961c2cc5f3..a403abfe723 100644
--- a/docs-devsite/firestore_.query.md
+++ b/docs-devsite/firestore_.query.md
@@ -15,7 +15,7 @@ A `Query` refers to a query which you can read or listen to. You can also constr
 <b>Signature:</b>
 
 ```typescript
-export declare class Query<T = DocumentData> 
+export declare class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Constructors
@@ -28,7 +28,7 @@ export declare class Query<T = DocumentData>
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [converter](./firestore_.query.md#queryconverter) |  | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;T&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
+|  [converter](./firestore_.query.md#queryconverter) |  | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;AppType, DbType&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
 |  [firestore](./firestore_.query.md#queryfirestore) |  | [Firestore](./firestore_.firestore.md#firestore_class) | The <code>Firestore</code> instance for the Firestore database (useful for performing transactions, etc.). |
 |  [type](./firestore_.query.md#querytype) |  | 'query' \| 'collection' | The type of this Firestore reference. |
 
@@ -56,7 +56,7 @@ If provided, the `FirestoreDataConverter` associated with this instance.
 <b>Signature:</b>
 
 ```typescript
-readonly converter: FirestoreDataConverter<T> | null;
+readonly converter: FirestoreDataConverter<AppType, DbType> | null;
 ```
 
 ## Query.firestore
@@ -86,7 +86,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): Query<DocumentData>;
+withConverter(converter: null): Query<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -97,7 +97,7 @@ withConverter(converter: null): Query<DocumentData>;
 
 <b>Returns:</b>
 
-[Query](./firestore_.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_.documentdata.md#documentdata_interface)<!-- -->&gt;
+[Query](./firestore_.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_.md#documentdata)<!-- -->, [DocumentData](./firestore_.md#documentdata)<!-- -->&gt;
 
 A `Query<DocumentData>` that does not use a converter.
 
@@ -108,18 +108,18 @@ Applies a custom data converter to this query, allowing you to use your own cust
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): Query<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[Query](./firestore_.query.md#query_class)<!-- -->&lt;U&gt;
+[Query](./firestore_.query.md#query_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `Query<U>` that uses the provided converter.
 
diff --git a/docs-devsite/firestore_.querydocumentsnapshot.md b/docs-devsite/firestore_.querydocumentsnapshot.md
index 0755a11915f..66aa1d62c91 100644
--- a/docs-devsite/firestore_.querydocumentsnapshot.md
+++ b/docs-devsite/firestore_.querydocumentsnapshot.md
@@ -17,9 +17,9 @@ A `QueryDocumentSnapshot` offers the same API surface as a `DocumentSnapshot`<!-
 <b>Signature:</b>
 
 ```typescript
-export declare class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<T> 
+export declare class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> 
 ```
-<b>Extends:</b> [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;
+<b>Extends:</b> [DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Methods
 
@@ -37,7 +37,7 @@ By default, `serverTimestamp()` values that have not yet been set to their final
 
 ```typescript
 /** @override */
-data(options?: SnapshotOptions): T;
+data(options?: SnapshotOptions): AppType;
 ```
 
 ### Parameters
@@ -48,7 +48,7 @@ data(options?: SnapshotOptions): T;
 
 <b>Returns:</b>
 
-T
+AppType
 
 An `Object` containing all fields in the document.
 
diff --git a/docs-devsite/firestore_.querysnapshot.md b/docs-devsite/firestore_.querysnapshot.md
index 0abb869c003..cea7d0d8238 100644
--- a/docs-devsite/firestore_.querysnapshot.md
+++ b/docs-devsite/firestore_.querysnapshot.md
@@ -15,17 +15,17 @@ A `QuerySnapshot` contains zero or more `DocumentSnapshot` objects representing
 <b>Signature:</b>
 
 ```typescript
-export declare class QuerySnapshot<T = DocumentData> 
+export declare class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [docs](./firestore_.querysnapshot.md#querysnapshotdocs) |  | Array&lt;[QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;&gt; | An array of all the documents in the <code>QuerySnapshot</code>. |
+|  [docs](./firestore_.querysnapshot.md#querysnapshotdocs) |  | Array&lt;[QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt; | An array of all the documents in the <code>QuerySnapshot</code>. |
 |  [empty](./firestore_.querysnapshot.md#querysnapshotempty) |  | boolean | True if there are no documents in the <code>QuerySnapshot</code>. |
 |  [metadata](./firestore_.querysnapshot.md#querysnapshotmetadata) |  | [SnapshotMetadata](./firestore_.snapshotmetadata.md#snapshotmetadata_class) | Metadata about this snapshot, concerning its source and if it has local modifications. |
-|  [query](./firestore_.querysnapshot.md#querysnapshotquery) |  | [Query](./firestore_.query.md#query_class)<!-- -->&lt;T&gt; | The query on which you called <code>get</code> or <code>onSnapshot</code> in order to get this <code>QuerySnapshot</code>. |
+|  [query](./firestore_.querysnapshot.md#querysnapshotquery) |  | [Query](./firestore_.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query on which you called <code>get</code> or <code>onSnapshot</code> in order to get this <code>QuerySnapshot</code>. |
 |  [size](./firestore_.querysnapshot.md#querysnapshotsize) |  | number | The number of documents in the <code>QuerySnapshot</code>. |
 
 ## Methods
@@ -42,7 +42,7 @@ An array of all the documents in the `QuerySnapshot`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-get docs(): Array<QueryDocumentSnapshot<T>>;
+get docs(): Array<QueryDocumentSnapshot<AppType, DbType>>;
 ```
 
 ## QuerySnapshot.empty
@@ -72,7 +72,7 @@ The query on which you called `get` or `onSnapshot` in order to get this `QueryS
 <b>Signature:</b>
 
 ```typescript
-readonly query: Query<T>;
+readonly query: Query<AppType, DbType>;
 ```
 
 ## QuerySnapshot.size
@@ -92,7 +92,7 @@ Returns an array of the documents changes since the last snapshot. If this is th
 <b>Signature:</b>
 
 ```typescript
-docChanges(options?: SnapshotListenOptions): Array<DocumentChange<T>>;
+docChanges(options?: SnapshotListenOptions): Array<DocumentChange<AppType, DbType>>;
 ```
 
 ### Parameters
@@ -103,7 +103,7 @@ docChanges(options?: SnapshotListenOptions): Array<DocumentChange<T>>;
 
 <b>Returns:</b>
 
-Array&lt;[DocumentChange](./firestore_.documentchange.md#documentchange_interface)<!-- -->&lt;T&gt;&gt;
+Array&lt;[DocumentChange](./firestore_.documentchange.md#documentchange_interface)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 ## QuerySnapshot.forEach()
 
@@ -112,14 +112,14 @@ Enumerates all of the documents in the `QuerySnapshot`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-forEach(callback: (result: QueryDocumentSnapshot<T>) => void, thisArg?: unknown): void;
+forEach(callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void, thisArg?: unknown): void;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  callback | (result: [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called with a <code>QueryDocumentSnapshot</code> for each document in the snapshot. |
+|  callback | (result: [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called with a <code>QueryDocumentSnapshot</code> for each document in the snapshot. |
 |  thisArg | unknown | The <code>this</code> binding for the callback. |
 
 <b>Returns:</b>
diff --git a/docs-devsite/firestore_.transaction.md b/docs-devsite/firestore_.transaction.md
index 24f0690bea4..cefe7578996 100644
--- a/docs-devsite/firestore_.transaction.md
+++ b/docs-devsite/firestore_.transaction.md
@@ -38,14 +38,14 @@ Deletes the document referred to by the provided [DocumentReference](./firestore
 <b>Signature:</b>
 
 ```typescript
-delete(documentRef: DocumentReference<unknown>): this;
+delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be deleted. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be deleted. |
 
 <b>Returns:</b>
 
@@ -60,18 +60,18 @@ Reads the document referenced by the provided [DocumentReference](./firestore_.d
 <b>Signature:</b>
 
 ```typescript
-get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be read. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be read. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `DocumentSnapshot` with the read data.
 
@@ -82,15 +82,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): this;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -109,15 +109,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): this;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 |  options | [SetOptions](./firestore_.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -137,15 +137,15 @@ Updates fields in the document referred to by the provided [DocumentReference](.
 <b>Signature:</b>
 
 ```typescript
-update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): this;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be updated. |
-|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
+|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -166,14 +166,14 @@ Nested fields can be updated by providing dot-separated field path strings or by
 <b>Signature:</b>
 
 ```typescript
-update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be updated. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
 |  field | string \| [FieldPath](./firestore_.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key/value pairs. |
diff --git a/docs-devsite/firestore_.writebatch.md b/docs-devsite/firestore_.writebatch.md
index 878cb66810a..e8815c69641 100644
--- a/docs-devsite/firestore_.writebatch.md
+++ b/docs-devsite/firestore_.writebatch.md
@@ -55,14 +55,14 @@ Deletes the document referred to by the provided [DocumentReference](./firestore
 <b>Signature:</b>
 
 ```typescript
-delete(documentRef: DocumentReference<unknown>): WriteBatch;
+delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be deleted. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be deleted. |
 
 <b>Returns:</b>
 
@@ -77,15 +77,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): WriteBatch;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [WithFieldValue](./firestore_.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -100,15 +100,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): WriteBatch;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [PartialWithFieldValue](./firestore_.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 |  options | [SetOptions](./firestore_.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -128,15 +128,15 @@ Updates fields in the document referred to by the provided [DocumentReference](.
 <b>Signature:</b>
 
 ```typescript
-update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): WriteBatch;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be updated. |
-|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
+|  data | [UpdateData](./firestore_.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -157,14 +157,14 @@ Nested fields can be update by providing dot-separated field path strings or by
 <b>Signature:</b>
 
 ```typescript
-update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be updated. |
+|  documentRef | [DocumentReference](./firestore_.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
 |  field | string \| [FieldPath](./firestore_.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key value pairs. |
diff --git a/docs-devsite/firestore_lite.aggregatequerysnapshot.md b/docs-devsite/firestore_lite.aggregatequerysnapshot.md
index 4b5d3120ba3..cba98d517db 100644
--- a/docs-devsite/firestore_lite.aggregatequerysnapshot.md
+++ b/docs-devsite/firestore_lite.aggregatequerysnapshot.md
@@ -15,14 +15,14 @@ The results of executing an aggregation query.
 <b>Signature:</b>
 
 ```typescript
-export declare class AggregateQuerySnapshot<T extends AggregateSpec> 
+export declare class AggregateQuerySnapshot<AggregateSpecType extends AggregateSpec, AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [query](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshotquery) |  | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;unknown&gt; | The underlying query over which the aggregations recorded in this <code>AggregateQuerySnapshot</code> were performed. |
+|  [query](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshotquery) |  | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The underlying query over which the aggregations recorded in this <code>AggregateQuerySnapshot</code> were performed. |
 |  [type](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshottype) |  | (not declared) | A type string to uniquely identify instances of this class. |
 
 ## Methods
@@ -38,7 +38,7 @@ The underlying query over which the aggregations recorded in this `AggregateQuer
 <b>Signature:</b>
 
 ```typescript
-readonly query: Query<unknown>;
+readonly query: Query<AppType, DbType>;
 ```
 
 ## AggregateQuerySnapshot.type
@@ -60,11 +60,11 @@ The keys of the returned object will be the same as those of the `AggregateSpec`
 <b>Signature:</b>
 
 ```typescript
-data(): AggregateSpecData<T>;
+data(): AggregateSpecData<AggregateSpecType>;
 ```
 <b>Returns:</b>
 
-[AggregateSpecData](./firestore_lite.md#aggregatespecdata)<!-- -->&lt;T&gt;
+[AggregateSpecData](./firestore_lite.md#aggregatespecdata)<!-- -->&lt;AggregateSpecType&gt;
 
 The results of the aggregations performed over the underlying query.
 
diff --git a/docs-devsite/firestore_lite.collectionreference.md b/docs-devsite/firestore_lite.collectionreference.md
index d446560a02f..b0d70b85ad3 100644
--- a/docs-devsite/firestore_lite.collectionreference.md
+++ b/docs-devsite/firestore_lite.collectionreference.md
@@ -15,16 +15,16 @@ A `CollectionReference` object can be used for adding documents, getting documen
 <b>Signature:</b>
 
 ```typescript
-export declare class CollectionReference<T = DocumentData> extends Query<T> 
+export declare class CollectionReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends Query<AppType, DbType> 
 ```
-<b>Extends:</b> [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt;
+<b>Extends:</b> [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
 |  [id](./firestore_lite.collectionreference.md#collectionreferenceid) |  | string | The collection's identifier. |
-|  [parent](./firestore_lite.collectionreference.md#collectionreferenceparent) |  | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt; \| null | A reference to the containing <code>DocumentReference</code> if this is a subcollection. If this isn't a subcollection, the reference is null. |
+|  [parent](./firestore_lite.collectionreference.md#collectionreferenceparent) |  | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt; \| null | A reference to the containing <code>DocumentReference</code> if this is a subcollection. If this isn't a subcollection, the reference is null. |
 |  [path](./firestore_lite.collectionreference.md#collectionreferencepath) |  | string | A string representing the path of the referenced collection (relative to the root of the database). |
 |  [type](./firestore_lite.collectionreference.md#collectionreferencetype) |  | (not declared) | The type of this Firestore reference. |
 
@@ -52,7 +52,7 @@ A reference to the containing `DocumentReference` if this is a subcollection. If
 <b>Signature:</b>
 
 ```typescript
-get parent(): DocumentReference<DocumentData> | null;
+get parent(): DocumentReference<DocumentData, DocumentData> | null;
 ```
 
 ## CollectionReference.path
@@ -82,18 +82,18 @@ Applies a custom data converter to this `CollectionReference`<!-- -->, allowing
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): CollectionReference<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): CollectionReference<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;U&gt;
+[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `CollectionReference<U>` that uses the provided converter.
 
@@ -104,7 +104,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): CollectionReference<DocumentData>;
+withConverter(converter: null): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -115,7 +115,7 @@ withConverter(converter: null): CollectionReference<DocumentData>;
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 A `CollectionReference<DocumentData>` that does not use a converter.
 
diff --git a/docs-devsite/firestore_lite.documentdata.md b/docs-devsite/firestore_lite.documentdata.md
deleted file mode 100644
index 09b5eb64b48..00000000000
--- a/docs-devsite/firestore_lite.documentdata.md
+++ /dev/null
@@ -1,19 +0,0 @@
-Project: /docs/reference/js/_project.yaml
-Book: /docs/reference/_book.yaml
-page_type: reference
-
-{% comment %}
-DO NOT EDIT THIS FILE!
-This is generated by the JS SDK team, and any local changes will be
-overwritten. Changes should be made in the source code at
-https://github.com/firebase/firebase-js-sdk
-{% endcomment %}
-
-# DocumentData interface
-Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->) consists of fields mapped to values.
-
-<b>Signature:</b>
-
-```typescript
-export declare interface DocumentData 
-```
diff --git a/docs-devsite/firestore_lite.documentreference.md b/docs-devsite/firestore_lite.documentreference.md
index 0e307435949..d42ccb0a827 100644
--- a/docs-devsite/firestore_lite.documentreference.md
+++ b/docs-devsite/firestore_lite.documentreference.md
@@ -15,17 +15,17 @@ A `DocumentReference` refers to a document location in a Firestore database and
 <b>Signature:</b>
 
 ```typescript
-export declare class DocumentReference<T = DocumentData> 
+export declare class DocumentReference<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [converter](./firestore_lite.documentreference.md#documentreferenceconverter) |  | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;T&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
+|  [converter](./firestore_lite.documentreference.md#documentreferenceconverter) |  | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;AppType, DbType&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
 |  [firestore](./firestore_lite.documentreference.md#documentreferencefirestore) |  | [Firestore](./firestore_lite.firestore.md#firestore_class) | The [Firestore](./firestore_.firestore.md#firestore_class) instance the document is in. This is useful for performing transactions, for example. |
 |  [id](./firestore_lite.documentreference.md#documentreferenceid) |  | string | The document's identifier within its collection. |
-|  [parent](./firestore_lite.documentreference.md#documentreferenceparent) |  | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | The collection this <code>DocumentReference</code> belongs to. |
+|  [parent](./firestore_lite.documentreference.md#documentreferenceparent) |  | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | The collection this <code>DocumentReference</code> belongs to. |
 |  [path](./firestore_lite.documentreference.md#documentreferencepath) |  | string | A string representing the path of the referenced document (relative to the root of the database). |
 |  [type](./firestore_lite.documentreference.md#documentreferencetype) |  | (not declared) | The type of this Firestore reference. |
 
@@ -43,7 +43,7 @@ If provided, the `FirestoreDataConverter` associated with this instance.
 <b>Signature:</b>
 
 ```typescript
-readonly converter: FirestoreDataConverter<T> | null;
+readonly converter: FirestoreDataConverter<AppType, DbType> | null;
 ```
 
 ## DocumentReference.firestore
@@ -73,7 +73,7 @@ The collection this `DocumentReference` belongs to.
 <b>Signature:</b>
 
 ```typescript
-get parent(): CollectionReference<T>;
+get parent(): CollectionReference<AppType, DbType>;
 ```
 
 ## DocumentReference.path
@@ -103,18 +103,18 @@ Applies a custom data converter to this `DocumentReference`<!-- -->, allowing yo
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): DocumentReference<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): DocumentReference<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;U&gt;
+[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `DocumentReference<U>` that uses the provided converter.
 
@@ -125,7 +125,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): DocumentReference<DocumentData>;
+withConverter(converter: null): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -136,7 +136,7 @@ withConverter(converter: null): DocumentReference<DocumentData>;
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 A `DocumentReference<DocumentData>` that does not use a converter.
 
diff --git a/docs-devsite/firestore_lite.documentsnapshot.md b/docs-devsite/firestore_lite.documentsnapshot.md
index cfea1feb919..2eedf006fed 100644
--- a/docs-devsite/firestore_lite.documentsnapshot.md
+++ b/docs-devsite/firestore_lite.documentsnapshot.md
@@ -17,7 +17,7 @@ For a `DocumentSnapshot` that points to a non-existing document, any data access
 <b>Signature:</b>
 
 ```typescript
-export declare class DocumentSnapshot<T = DocumentData> 
+export declare class DocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Constructors
@@ -31,7 +31,7 @@ export declare class DocumentSnapshot<T = DocumentData>
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
 |  [id](./firestore_lite.documentsnapshot.md#documentsnapshotid) |  | string | Property of the <code>DocumentSnapshot</code> that provides the document's ID. |
-|  [ref](./firestore_lite.documentsnapshot.md#documentsnapshotref) |  | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | The <code>DocumentReference</code> for the document included in the <code>DocumentSnapshot</code>. |
+|  [ref](./firestore_lite.documentsnapshot.md#documentsnapshotref) |  | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | The <code>DocumentReference</code> for the document included in the <code>DocumentSnapshot</code>. |
 
 ## Methods
 
@@ -68,7 +68,7 @@ The `DocumentReference` for the document included in the `DocumentSnapshot`<!--
 <b>Signature:</b>
 
 ```typescript
-get ref(): DocumentReference<T>;
+get ref(): DocumentReference<AppType, DbType>;
 ```
 
 ## DocumentSnapshot.data()
@@ -78,11 +78,11 @@ Retrieves all fields in the document as an `Object`<!-- -->. Returns `undefined`
 <b>Signature:</b>
 
 ```typescript
-data(): T | undefined;
+data(): AppType | undefined;
 ```
 <b>Returns:</b>
 
-T \| undefined
+AppType \| undefined
 
 An `Object` containing all fields in the document or `undefined` if the document doesn't exist.
 
@@ -93,11 +93,11 @@ Signals whether or not the document at the snapshot's location exists.
 <b>Signature:</b>
 
 ```typescript
-exists(): this is QueryDocumentSnapshot<T>;
+exists(): this is QueryDocumentSnapshot<AppType, DbType>;
 ```
 <b>Returns:</b>
 
-this is [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;
+this is [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;
 
 true if the document exists.
 
diff --git a/docs-devsite/firestore_lite.firestoredataconverter.md b/docs-devsite/firestore_lite.firestoredataconverter.md
index 00510e0c22b..0ed1cf8cc66 100644
--- a/docs-devsite/firestore_lite.firestoredataconverter.md
+++ b/docs-devsite/firestore_lite.firestoredataconverter.md
@@ -10,88 +10,88 @@ https://github.com/firebase/firebase-js-sdk
 {% endcomment %}
 
 # FirestoreDataConverter interface
-Converter used by `withConverter()` to transform user objects of type `T` into Firestore data.
+Converter used by `withConverter()` to transform user objects of type `AppType` into Firestore data.
 
 Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore.
 
 <b>Signature:</b>
 
 ```typescript
-export declare interface FirestoreDataConverter<T> 
+export declare interface FirestoreDataConverter<AppType, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Methods
 
 |  Method | Description |
 |  --- | --- |
-|  [fromFirestore(snapshot)](./firestore_lite.firestoredataconverter.md#firestoredataconverterfromfirestore) | Called by the Firestore SDK to convert Firestore data into an object of type T. You can access your data by calling: <code>snapshot.data()</code>. |
-|  [toFirestore(modelObject)](./firestore_lite.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>T</code> into a plain Javascript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and .<!-- -->The <code>WithFieldValue&lt;T&gt;</code> type extends <code>T</code> to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values. |
-|  [toFirestore(modelObject, options)](./firestore_lite.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>T</code> into a plain Javascript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and  with <code>merge:true</code> or <code>mergeFields</code>.<!-- -->The <code>PartialWithFieldValue&lt;T&gt;</code> type extends <code>Partial&lt;T&gt;</code> to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested <code>Partial</code> by allowing nested fields to be omitted. |
+|  [fromFirestore(snapshot)](./firestore_lite.firestoredataconverter.md#firestoredataconverterfromfirestore) | Called by the Firestore SDK to convert Firestore data <code>DbType</code> into an object of type <code>AppType</code>. You can access your data by calling <code>snapshot.data()</code>. |
+|  [toFirestore(modelObject)](./firestore_lite.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>AppType</code> into a plain Javascript object, <code>DbType</code> (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and .<!-- -->The <code>WithFieldValue&lt;T&gt;</code> type extends <code>T</code> to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values. |
+|  [toFirestore(modelObject, options)](./firestore_lite.firestoredataconverter.md#firestoredataconvertertofirestore) | Called by the Firestore SDK to convert a custom model object of type <code>AppType</code> into a plain Javascript object, <code>DbType</code> (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and  with <code>merge:true</code> or <code>mergeFields</code>.<!-- -->The <code>PartialWithFieldValue&lt;T&gt;</code> type extends <code>Partial&lt;T&gt;</code> to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested <code>Partial</code> by allowing nested fields to be omitted. |
 
 ## FirestoreDataConverter.fromFirestore()
 
-Called by the Firestore SDK to convert Firestore data into an object of type T. You can access your data by calling: `snapshot.data()`<!-- -->.
+Called by the Firestore SDK to convert Firestore data `DbType` into an object of type `AppType`<!-- -->. You can access your data by calling `snapshot.data()`<!-- -->.
 
 <b>Signature:</b>
 
 ```typescript
-fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>): T;
+fromFirestore(snapshot: QueryDocumentSnapshot<DbType, DbType>): AppType;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  snapshot | [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt; | A <code>QueryDocumentSnapshot</code> containing your data and metadata. |
+|  snapshot | [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;DbType, DbType&gt; | A <code>QueryDocumentSnapshot</code> containing your data and metadata. |
 
 <b>Returns:</b>
 
-T
+AppType
 
 ## FirestoreDataConverter.toFirestore()
 
-Called by the Firestore SDK to convert a custom model object of type `T` into a plain Javascript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and .
+Called by the Firestore SDK to convert a custom model object of type `AppType` into a plain Javascript object, `DbType` (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and .
 
 The `WithFieldValue<T>` type extends `T` to also allow FieldValues such as [deleteField()](./firestore_.md#deletefield) to be used as property values.
 
 <b>Signature:</b>
 
 ```typescript
-toFirestore(modelObject: WithFieldValue<T>): DocumentData;
+toFirestore(modelObject: WithFieldValue<AppType>): WithFieldValue<DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  modelObject | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;T&gt; |  |
+|  modelObject | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;AppType&gt; |  |
 
 <b>Returns:</b>
 
-[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)
+[WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;DbType&gt;
 
 ## FirestoreDataConverter.toFirestore()
 
-Called by the Firestore SDK to convert a custom model object of type `T` into a plain Javascript object (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and  with `merge:true` or `mergeFields`<!-- -->.
+Called by the Firestore SDK to convert a custom model object of type `AppType` into a plain Javascript object, `DbType` (suitable for writing directly to the Firestore database). Used with [setDoc()](./firestore_lite.md#setdoc)<!-- -->,  and  with `merge:true` or `mergeFields`<!-- -->.
 
 The `PartialWithFieldValue<T>` type extends `Partial<T>` to allow FieldValues such as [arrayUnion()](./firestore_.md#arrayunion) to be used as property values. It also supports nested `Partial` by allowing nested fields to be omitted.
 
 <b>Signature:</b>
 
 ```typescript
-toFirestore(modelObject: PartialWithFieldValue<T>, options: SetOptions): DocumentData;
+toFirestore(modelObject: PartialWithFieldValue<AppType>, options: SetOptions): PartialWithFieldValue<DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  modelObject | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;T&gt; |  |
+|  modelObject | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; |  |
 |  options | [SetOptions](./firestore_lite.md#setoptions) |  |
 
 <b>Returns:</b>
 
-[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)
+[PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;DbType&gt;
 
 ### Example
 
@@ -105,7 +105,7 @@ class Post {
   }
 }
 
-const postConverter = {
+const postConverter: FirestoreDataConverter<Post, DocumentData> = {
   toFirestore(post: WithFieldValue<Post>): DocumentData {
     return {title: post.title, author: post.author};
   },
diff --git a/docs-devsite/firestore_lite.md b/docs-devsite/firestore_lite.md
index b0ec302e722..886ad48fbd0 100644
--- a/docs-devsite/firestore_lite.md
+++ b/docs-devsite/firestore_lite.md
@@ -114,8 +114,7 @@ https://github.com/firebase/firebase-js-sdk
 |  Interface | Description |
 |  --- | --- |
 |  [AggregateSpec](./firestore_lite.aggregatespec.md#aggregatespec_interface) | Specifies a set of aggregations and their aliases. |
-|  [DocumentData](./firestore_lite.documentdata.md#documentdata_interface) | Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->) consists of fields mapped to values. |
-|  [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface) | Converter used by <code>withConverter()</code> to transform user objects of type <code>T</code> into Firestore data.<!-- -->Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore. |
+|  [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface) | Converter used by <code>withConverter()</code> to transform user objects of type <code>AppType</code> into Firestore data.<!-- -->Using the converter allows you to specify generic type arguments when storing and retrieving objects from Firestore. |
 |  [Settings](./firestore_lite.settings.md#settings_interface) | Specifies custom configurations for your Cloud Firestore instance. You must set these before invoking any other methods. |
 |  [TransactionOptions](./firestore_lite.transactionoptions.md#transactionoptions_interface) | Options to customize transaction behavior. |
 
@@ -127,6 +126,7 @@ https://github.com/firebase/firebase-js-sdk
 |  [AggregateFieldType](./firestore_lite.md#aggregatefieldtype) | The union of all <code>AggregateField</code> types that are supported by Firestore. |
 |  [AggregateSpecData](./firestore_lite.md#aggregatespecdata) | A type whose keys are taken from an <code>AggregateSpec</code>, and whose values are the result of the aggregation performed by the corresponding <code>AggregateField</code> from the input <code>AggregateSpec</code>. |
 |  [ChildUpdateFields](./firestore_lite.md#childupdatefields) | Helper for calculating the nested fields for a given type T1. This is needed to distribute union types such as <code>undefined &#124; {...}</code> (happens for optional props) or <code>{a: A} &#124; {b: B}</code>.<!-- -->In this use case, <code>V</code> is used to distribute the union types of <code>T[K]</code> on <code>Record</code>, since <code>T[K]</code> is evaluated as an expression and not distributed.<!-- -->See https://www.typescriptlang.org/docs/handbook/advanced-types.html\#distributive-conditional-types |
+|  [DocumentData](./firestore_lite.md#documentdata) | Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->). Must be an object with string keys. |
 |  [FirestoreErrorCode](./firestore_lite.md#firestoreerrorcode) | The set of Firestore status codes. The codes are the same at the ones exposed by gRPC here: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md<!-- -->Possible values: - 'cancelled': The operation was cancelled (typically by the caller). - 'unknown': Unknown error or an error from a different error domain. - 'invalid-argument': Client specified an invalid argument. Note that this differs from 'failed-precondition'. 'invalid-argument' indicates arguments that are problematic regardless of the state of the system (e.g. an invalid field name). - 'deadline-exceeded': Deadline expired before operation could complete. For operations that change the state of the system, this error may be returned even if the operation has completed successfully. For example, a successful response from a server could have been delayed long enough for the deadline to expire. - 'not-found': Some requested document was not found. - 'already-exists': Some document that we attempted to create already exists. - 'permission-denied': The caller does not have permission to execute the specified operation. - 'resource-exhausted': Some resource has been exhausted, perhaps a per-user quota, or perhaps the entire file system is out of space. - 'failed-precondition': Operation was rejected because the system is not in a state required for the operation's execution. - 'aborted': The operation was aborted, typically due to a concurrency issue like transaction aborts, etc. - 'out-of-range': Operation was attempted past the valid range. - 'unimplemented': Operation is not implemented or not supported/enabled. - 'internal': Internal errors. Means some invariants expected by underlying system has been broken. If you see one of these errors, something is very broken. - 'unavailable': The service is currently unavailable. This is most likely a transient condition and may be corrected by retrying with a backoff. - 'data-loss': Unrecoverable data loss or corruption. - 'unauthenticated': The request does not have valid authentication credentials for the operation. |
 |  [NestedUpdateFields](./firestore_lite.md#nestedupdatefields) | For each field (e.g. 'bar'), find all nested keys (e.g. {<!-- -->'bar.baz': T1, 'bar.qux': T2<!-- -->}<!-- -->). Intersect them together to make a single map containing all possible keys that are all marked as optional |
 |  [OrderByDirection](./firestore_lite.md#orderbydirection) | The direction of a [orderBy()](./firestore_.md#orderby) clause is specified as 'desc' or 'asc' (descending or ascending). |
@@ -193,7 +193,7 @@ Gets a `CollectionReference` instance that refers to the collection at the speci
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -206,7 +206,7 @@ export declare function collection(firestore: Firestore, path: string, ...pathSe
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -221,7 +221,7 @@ Creates and returns a new `Query` instance that includes all documents in the da
 <b>Signature:</b>
 
 ```typescript
-export declare function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData>;
+export declare function collectionGroup(firestore: Firestore, collectionId: string): Query<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -233,7 +233,7 @@ export declare function collectionGroup(firestore: Firestore, collectionId: stri
 
 <b>Returns:</b>
 
-[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The created `Query`<!-- -->.
 
@@ -271,7 +271,7 @@ Gets a `DocumentReference` instance that refers to the document at the specified
 <b>Signature:</b>
 
 ```typescript
-export declare function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export declare function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -284,7 +284,7 @@ export declare function doc(firestore: Firestore, path: string, ...pathSegments:
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The `DocumentReference` instance.
 
@@ -614,15 +614,15 @@ Two `AggregateQuerySnapshot` instances are considered "equal" if they have under
 <b>Signature:</b>
 
 ```typescript
-export declare function aggregateQuerySnapshotEqual<T extends AggregateSpec>(left: AggregateQuerySnapshot<T>, right: AggregateQuerySnapshot<T>): boolean;
+export declare function aggregateQuerySnapshotEqual<AggregateSpecType extends AggregateSpec>(left: AggregateQuerySnapshot<AggregateSpecType>, right: AggregateQuerySnapshot<AggregateSpecType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;T&gt; | The first <code>AggregateQuerySnapshot</code> to compare. |
-|  right | [AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;T&gt; | The second <code>AggregateQuerySnapshot</code> to compare. |
+|  left | [AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;AggregateSpecType&gt; | The first <code>AggregateQuerySnapshot</code> to compare. |
+|  right | [AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;AggregateSpecType&gt; | The second <code>AggregateQuerySnapshot</code> to compare. |
 
 <b>Returns:</b>
 
@@ -637,15 +637,15 @@ Returns true if the provided queries point to the same collection and apply the
 <b>Signature:</b>
 
 ```typescript
-export declare function queryEqual<T>(left: Query<T>, right: Query<T>): boolean;
+export declare function queryEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: Query<AppType, DbType>, right: Query<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | A <code>Query</code> to compare. |
-|  right | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | A <code>Query</code> to compare. |
+|  left | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | A <code>Query</code> to compare. |
+|  right | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | A <code>Query</code> to compare. |
 
 <b>Returns:</b>
 
@@ -660,15 +660,15 @@ Returns true if the provided references are equal.
 <b>Signature:</b>
 
 ```typescript
-export declare function refEqual<T>(left: DocumentReference<T> | CollectionReference<T>, right: DocumentReference<T> | CollectionReference<T>): boolean;
+export declare function refEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>, right: DocumentReference<AppType, DbType> | CollectionReference<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; \| [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to compare. |
-|  right | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; \| [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to compare. |
+|  left | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; \| [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to compare. |
+|  right | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; \| [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to compare. |
 
 <b>Returns:</b>
 
@@ -683,15 +683,15 @@ Returns true if the provided snapshots are equal.
 <b>Signature:</b>
 
 ```typescript
-export declare function snapshotEqual<T>(left: DocumentSnapshot<T> | QuerySnapshot<T>, right: DocumentSnapshot<T> | QuerySnapshot<T>): boolean;
+export declare function snapshotEqual<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(left: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>, right: DocumentSnapshot<AppType, DbType> | QuerySnapshot<AppType, DbType>): boolean;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  left | [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt; \| [QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt; | A snapshot to compare. |
-|  right | [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt; \| [QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt; | A snapshot to compare. |
+|  left | [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt; \| [QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt; | A snapshot to compare. |
+|  right | [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt; \| [QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt; | A snapshot to compare. |
 
 <b>Returns:</b>
 
@@ -800,20 +800,20 @@ Using this function to count the documents is efficient because only the final c
 <b>Signature:</b>
 
 ```typescript
-export declare function getCount(query: Query<unknown>): Promise<AggregateQuerySnapshot<{
+export declare function getCount<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<AggregateQuerySnapshot<{
     count: AggregateField<number>;
-}>>;
+}, AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;unknown&gt; | The query whose result set size to calculate. |
+|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query whose result set size to calculate. |
 
 <b>Returns:</b>
 
-Promise&lt;[AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;{ count: [AggregateField](./firestore_lite.aggregatefield.md#aggregatefield_class)<!-- -->&lt;number&gt;; }&gt;&gt;
+Promise&lt;[AggregateQuerySnapshot](./firestore_lite.aggregatequerysnapshot.md#aggregatequerysnapshot_class)<!-- -->&lt;{ count: [AggregateField](./firestore_lite.aggregatefield.md#aggregatefield_class)<!-- -->&lt;number&gt;; }, AppType, DbType&gt;&gt;
 
 A Promise that will be resolved with the count; the count can be retrieved from `snapshot.data().count`<!-- -->, where `snapshot` is the `AggregateQuerySnapshot` to which the returned Promise resolves.
 
@@ -826,18 +826,18 @@ All queries are executed directly by the server, even if the the query was previ
 <b>Signature:</b>
 
 ```typescript
-export declare function getDocs<T>(query: Query<T>): Promise<QuerySnapshot<T>>;
+export declare function getDocs<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>): Promise<QuerySnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | The <code>Query</code> to execute. |
+|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The <code>Query</code> to execute. |
 
 <b>Returns:</b>
 
-Promise&lt;[QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[QuerySnapshot](./firestore_lite.querysnapshot.md#querysnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A Promise that will be resolved with the results of the query.
 
@@ -848,20 +848,20 @@ Creates a new immutable instance of [Query](./firestore_.query.md#query_class) t
 <b>Signature:</b>
 
 ```typescript
-export declare function query<T>(query: Query<T>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<T>;
+export declare function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, compositeFilter: QueryCompositeFilterConstraint, ...queryConstraints: QueryNonFilterConstraint[]): Query<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
+|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
 |  compositeFilter | [QueryCompositeFilterConstraint](./firestore_lite.querycompositefilterconstraint.md#querycompositefilterconstraint_class) | The [QueryCompositeFilterConstraint](./firestore_.querycompositefilterconstraint.md#querycompositefilterconstraint_class) to apply. Create [QueryCompositeFilterConstraint](./firestore_.querycompositefilterconstraint.md#querycompositefilterconstraint_class) using [and()](./firestore_.md#and) or [or()](./firestore_.md#or)<!-- -->. |
 |  queryConstraints | [QueryNonFilterConstraint](./firestore_lite.md#querynonfilterconstraint)<!-- -->\[\] | Additional [QueryNonFilterConstraint](./firestore_.md#querynonfilterconstraint)<!-- -->s to apply (e.g. [orderBy()](./firestore_.md#orderby)<!-- -->, [limit()](./firestore_.md#limit)<!-- -->). |
 
 <b>Returns:</b>
 
-[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt;
+[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Exceptions
 
@@ -874,19 +874,19 @@ Creates a new immutable instance of [Query](./firestore_.query.md#query_class) t
 <b>Signature:</b>
 
 ```typescript
-export declare function query<T>(query: Query<T>, ...queryConstraints: QueryConstraint[]): Query<T>;
+export declare function query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(query: Query<AppType, DbType>, ...queryConstraints: QueryConstraint[]): Query<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
+|  query | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The [Query](./firestore_.query.md#query_class) instance to use as a base for the new constraints. |
 |  queryConstraints | [QueryConstraint](./firestore_lite.queryconstraint.md#queryconstraint_class)<!-- -->\[\] | The list of [QueryConstraint](./firestore_.queryconstraint.md#queryconstraint_class)<!-- -->s to apply. |
 
 <b>Returns:</b>
 
-[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt;
+[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Exceptions
 
@@ -945,19 +945,19 @@ The result of this write will only be reflected in document reads that occur aft
 <b>Signature:</b>
 
 ```typescript
-export declare function addDoc<T>(reference: CollectionReference<T>, data: WithFieldValue<T>): Promise<DocumentReference<T>>;
+export declare function addDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<DocumentReference<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to the collection to add this document to. |
-|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;T&gt; | An Object containing the data for the new document. |
+|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the collection to add this document to. |
+|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An Object containing the data for the new document. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `Promise` resolved with a `DocumentReference` pointing to the newly created document after it has been written to the backend.
 
@@ -972,20 +972,20 @@ Gets a `CollectionReference` instance that refers to a subcollection of `referen
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(reference: CollectionReference<unknown>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;unknown&gt; | A reference to a collection. |
+|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a collection. |
 |  path | string | A slash-separated path to a collection. |
 |  pathSegments | string\[\] | Additional path segments to apply relative to the first argument. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -1000,20 +1000,20 @@ Gets a `CollectionReference` instance that refers to a subcollection of `referen
 <b>Signature:</b>
 
 ```typescript
-export declare function collection(reference: DocumentReference, path: string, ...pathSegments: string[]): CollectionReference<DocumentData>;
+export declare function collection<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class) | A reference to a Firestore document. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a Firestore document. |
 |  path | string | A slash-separated path to a collection. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The `CollectionReference` instance.
 
@@ -1030,14 +1030,14 @@ The deletion will only be reflected in document reads that occur after the retur
 <b>Signature:</b>
 
 ```typescript
-export declare function deleteDoc(reference: DocumentReference<unknown>): Promise<void>;
+export declare function deleteDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to delete. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to delete. |
 
 <b>Returns:</b>
 
@@ -1052,20 +1052,20 @@ Gets a `DocumentReference` instance that refers to a document within `reference`
 <b>Signature:</b>
 
 ```typescript
-export declare function doc<T>(reference: CollectionReference<T>, path?: string, ...pathSegments: string[]): DocumentReference<T>;
+export declare function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: CollectionReference<AppType, DbType>, path?: string, ...pathSegments: string[]): DocumentReference<AppType, DbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;T&gt; | A reference to a collection. |
+|  reference | [CollectionReference](./firestore_lite.collectionreference.md#collectionreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a collection. |
 |  path | string | A slash-separated path to a document. Has to be omitted to use auto-genrated IDs. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt;
+[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt;
 
 The `DocumentReference` instance.
 
@@ -1080,20 +1080,20 @@ Gets a `DocumentReference` instance that refers to a document within `reference`
 <b>Signature:</b>
 
 ```typescript
-export declare function doc(reference: DocumentReference<unknown>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData>;
+export declare function doc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to a Firestore document. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to a Firestore document. |
 |  path | string | A slash-separated path to a document. |
 |  pathSegments | string\[\] | Additional path segments that will be applied relative to the first argument. |
 
 <b>Returns:</b>
 
-[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 The `DocumentReference` instance.
 
@@ -1110,18 +1110,18 @@ All documents are directly fetched from the server, even if the document was pre
 <b>Signature:</b>
 
 ```typescript
-export declare function getDoc<T>(reference: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+export declare function getDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | The reference of the document to fetch. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | The reference of the document to fetch. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A Promise resolved with a `DocumentSnapshot` containing the current document contents.
 
@@ -1134,15 +1134,15 @@ The result of this write will only be reflected in document reads that occur aft
 <b>Signature:</b>
 
 ```typescript
-export declare function setDoc<T>(reference: DocumentReference<T>, data: WithFieldValue<T>): Promise<void>;
+export declare function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to write. |
-|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;T&gt; | A map of the fields and values for the document. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to write. |
+|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;AppType&gt; | A map of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -1163,15 +1163,15 @@ The result of this write will only be reflected in document reads that occur aft
 <b>Signature:</b>
 
 ```typescript
-export declare function setDoc<T>(reference: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): Promise<void>;
+export declare function setDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to write. |
-|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | A map of the fields and values for the document. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to write. |
+|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | A map of the fields and values for the document. |
 |  options | [SetOptions](./firestore_lite.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -1193,15 +1193,15 @@ The result of this update will only be reflected in document reads that occur af
 <b>Signature:</b>
 
 ```typescript
-export declare function updateDoc<T>(reference: DocumentReference<T>, data: UpdateData<T>): Promise<void>;
+export declare function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to update. |
-|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to update. |
+|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -1224,14 +1224,14 @@ The result of this update will only be reflected in document reads that occur af
 <b>Signature:</b>
 
 ```typescript
-export declare function updateDoc(reference: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
+export declare function updateDoc<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData>(reference: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): Promise<void>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to update. |
+|  reference | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to update. |
 |  field | string \| [FieldPath](./firestore_lite.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key value pairs. |
@@ -1382,6 +1382,16 @@ See https://www.typescriptlang.org/docs/handbook/advanced-types.html\#distributi
 export declare type ChildUpdateFields<K extends string, V> = V extends Record<string, unknown> ? AddPrefixToKeys<K, UpdateData<V>> : never;
 ```
 
+## DocumentData
+
+Document data (for use with [setDoc()](./firestore_lite.md#setdoc)<!-- -->). Must be an object with string keys.
+
+<b>Signature:</b>
+
+```typescript
+export declare type DocumentData = Record<string, any>;
+```
+
 ## FirestoreErrorCode
 
 The set of Firestore status codes. The codes are the same at the ones exposed by gRPC here: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
diff --git a/docs-devsite/firestore_lite.query.md b/docs-devsite/firestore_lite.query.md
index f2eac7560dc..3db1ca9e91f 100644
--- a/docs-devsite/firestore_lite.query.md
+++ b/docs-devsite/firestore_lite.query.md
@@ -15,7 +15,7 @@ A `Query` refers to a query which you can read or listen to. You can also constr
 <b>Signature:</b>
 
 ```typescript
-export declare class Query<T = DocumentData> 
+export declare class Query<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Constructors
@@ -28,7 +28,7 @@ export declare class Query<T = DocumentData>
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [converter](./firestore_lite.query.md#queryconverter) |  | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;T&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
+|  [converter](./firestore_lite.query.md#queryconverter) |  | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;AppType, DbType&gt; \| null | If provided, the <code>FirestoreDataConverter</code> associated with this instance. |
 |  [firestore](./firestore_lite.query.md#queryfirestore) |  | [Firestore](./firestore_lite.firestore.md#firestore_class) | The <code>Firestore</code> instance for the Firestore database (useful for performing transactions, etc.). |
 |  [type](./firestore_lite.query.md#querytype) |  | 'query' \| 'collection' | The type of this Firestore reference. |
 
@@ -56,7 +56,7 @@ If provided, the `FirestoreDataConverter` associated with this instance.
 <b>Signature:</b>
 
 ```typescript
-readonly converter: FirestoreDataConverter<T> | null;
+readonly converter: FirestoreDataConverter<AppType, DbType> | null;
 ```
 
 ## Query.firestore
@@ -86,7 +86,7 @@ Removes the current converter.
 <b>Signature:</b>
 
 ```typescript
-withConverter(converter: null): Query<DocumentData>;
+withConverter(converter: null): Query<DocumentData, DocumentData>;
 ```
 
 ### Parameters
@@ -97,7 +97,7 @@ withConverter(converter: null): Query<DocumentData>;
 
 <b>Returns:</b>
 
-[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_lite.documentdata.md#documentdata_interface)<!-- -->&gt;
+[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;[DocumentData](./firestore_lite.md#documentdata)<!-- -->, [DocumentData](./firestore_lite.md#documentdata)<!-- -->&gt;
 
 A `Query<DocumentData>` that does not use a converter.
 
@@ -108,18 +108,18 @@ Applies a custom data converter to this query, allowing you to use your own cust
 <b>Signature:</b>
 
 ```typescript
-withConverter<U>(converter: FirestoreDataConverter<U>): Query<U>;
+withConverter<NewAppType = DocumentData, NewDbType extends DocumentData = NewAppType extends DocumentData ? NewAppType : DocumentData>(converter: FirestoreDataConverter<NewAppType, NewDbType>): Query<NewAppType, NewDbType>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;U&gt; | Converts objects to and from Firestore. |
+|  converter | [FirestoreDataConverter](./firestore_lite.firestoredataconverter.md#firestoredataconverter_interface)<!-- -->&lt;NewAppType, NewDbType&gt; | Converts objects to and from Firestore. |
 
 <b>Returns:</b>
 
-[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;U&gt;
+[Query](./firestore_lite.query.md#query_class)<!-- -->&lt;NewAppType, NewDbType&gt;
 
 A `Query<U>` that uses the provided converter.
 
diff --git a/docs-devsite/firestore_lite.querydocumentsnapshot.md b/docs-devsite/firestore_lite.querydocumentsnapshot.md
index 356d7ecaeed..15ab55264a9 100644
--- a/docs-devsite/firestore_lite.querydocumentsnapshot.md
+++ b/docs-devsite/firestore_lite.querydocumentsnapshot.md
@@ -17,9 +17,9 @@ A `QueryDocumentSnapshot` offers the same API surface as a `DocumentSnapshot`<!-
 <b>Signature:</b>
 
 ```typescript
-export declare class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<T> 
+export declare class QueryDocumentSnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> extends DocumentSnapshot<AppType, DbType> 
 ```
-<b>Extends:</b> [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;
+<b>Extends:</b> [DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;
 
 ## Methods
 
@@ -35,11 +35,11 @@ Retrieves all fields in the document as an `Object`<!-- -->.
 
 ```typescript
 /** @override */
-data(): T;
+data(): AppType;
 ```
 <b>Returns:</b>
 
-T
+AppType
 
 An `Object` containing all fields in the document.
 
diff --git a/docs-devsite/firestore_lite.querysnapshot.md b/docs-devsite/firestore_lite.querysnapshot.md
index 8e805af948d..d144bd133c1 100644
--- a/docs-devsite/firestore_lite.querysnapshot.md
+++ b/docs-devsite/firestore_lite.querysnapshot.md
@@ -15,16 +15,16 @@ A `QuerySnapshot` contains zero or more `DocumentSnapshot` objects representing
 <b>Signature:</b>
 
 ```typescript
-export declare class QuerySnapshot<T = DocumentData> 
+export declare class QuerySnapshot<AppType = DocumentData, DbType extends DocumentData = AppType extends DocumentData ? AppType : DocumentData> 
 ```
 
 ## Properties
 
 |  Property | Modifiers | Type | Description |
 |  --- | --- | --- | --- |
-|  [docs](./firestore_lite.querysnapshot.md#querysnapshotdocs) |  | Array&lt;[QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;&gt; | An array of all the documents in the <code>QuerySnapshot</code>. |
+|  [docs](./firestore_lite.querysnapshot.md#querysnapshotdocs) |  | Array&lt;[QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt; | An array of all the documents in the <code>QuerySnapshot</code>. |
 |  [empty](./firestore_lite.querysnapshot.md#querysnapshotempty) |  | boolean | True if there are no documents in the <code>QuerySnapshot</code>. |
-|  [query](./firestore_lite.querysnapshot.md#querysnapshotquery) |  | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;T&gt; | The query on which you called [getDocs()](./firestore_.md#getdocs) in order to get this <code>QuerySnapshot</code>. |
+|  [query](./firestore_lite.querysnapshot.md#querysnapshotquery) |  | [Query](./firestore_lite.query.md#query_class)<!-- -->&lt;AppType, DbType&gt; | The query on which you called [getDocs()](./firestore_.md#getdocs) in order to get this <code>QuerySnapshot</code>. |
 |  [size](./firestore_lite.querysnapshot.md#querysnapshotsize) |  | number | The number of documents in the <code>QuerySnapshot</code>. |
 
 ## Methods
@@ -40,7 +40,7 @@ An array of all the documents in the `QuerySnapshot`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-get docs(): Array<QueryDocumentSnapshot<T>>;
+get docs(): Array<QueryDocumentSnapshot<AppType, DbType>>;
 ```
 
 ## QuerySnapshot.empty
@@ -60,7 +60,7 @@ The query on which you called [getDocs()](./firestore_.md#getdocs) in order to g
 <b>Signature:</b>
 
 ```typescript
-readonly query: Query<T>;
+readonly query: Query<AppType, DbType>;
 ```
 
 ## QuerySnapshot.size
@@ -80,14 +80,14 @@ Enumerates all of the documents in the `QuerySnapshot`<!-- -->.
 <b>Signature:</b>
 
 ```typescript
-forEach(callback: (result: QueryDocumentSnapshot<T>) => void, thisArg?: unknown): void;
+forEach(callback: (result: QueryDocumentSnapshot<AppType, DbType>) => void, thisArg?: unknown): void;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  callback | (result: [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;T&gt;) =&gt; void | A callback to be called with a <code>QueryDocumentSnapshot</code> for each document in the snapshot. |
+|  callback | (result: [QueryDocumentSnapshot](./firestore_lite.querydocumentsnapshot.md#querydocumentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;) =&gt; void | A callback to be called with a <code>QueryDocumentSnapshot</code> for each document in the snapshot. |
 |  thisArg | unknown | The <code>this</code> binding for the callback. |
 
 <b>Returns:</b>
diff --git a/docs-devsite/firestore_lite.transaction.md b/docs-devsite/firestore_lite.transaction.md
index c643f08d66e..f730c171a42 100644
--- a/docs-devsite/firestore_lite.transaction.md
+++ b/docs-devsite/firestore_lite.transaction.md
@@ -38,14 +38,14 @@ Deletes the document referred to by the provided [DocumentReference](./firestore
 <b>Signature:</b>
 
 ```typescript
-delete(documentRef: DocumentReference<unknown>): this;
+delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be deleted. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be deleted. |
 
 <b>Returns:</b>
 
@@ -60,18 +60,18 @@ Reads the document referenced by the provided [DocumentReference](./firestore_.d
 <b>Signature:</b>
 
 ```typescript
-get<T>(documentRef: DocumentReference<T>): Promise<DocumentSnapshot<T>>;
+get<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): Promise<DocumentSnapshot<AppType, DbType>>;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be read. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be read. |
 
 <b>Returns:</b>
 
-Promise&lt;[DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;T&gt;&gt;
+Promise&lt;[DocumentSnapshot](./firestore_lite.documentsnapshot.md#documentsnapshot_class)<!-- -->&lt;AppType, DbType&gt;&gt;
 
 A `DocumentSnapshot` with the read data.
 
@@ -82,15 +82,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): this;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -109,15 +109,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): this;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 |  options | [SetOptions](./firestore_lite.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -137,15 +137,15 @@ Updates fields in the document referred to by the provided [DocumentReference](.
 <b>Signature:</b>
 
 ```typescript
-update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): this;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be updated. |
-|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
+|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -166,14 +166,14 @@ Nested fields can be updated by providing dot-separated field path strings or by
 <b>Signature:</b>
 
 ```typescript
-update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): this;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be updated. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
 |  field | string \| [FieldPath](./firestore_lite.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key/value pairs. |
diff --git a/docs-devsite/firestore_lite.writebatch.md b/docs-devsite/firestore_lite.writebatch.md
index 141a99e8585..3c1896f8424 100644
--- a/docs-devsite/firestore_lite.writebatch.md
+++ b/docs-devsite/firestore_lite.writebatch.md
@@ -55,14 +55,14 @@ Deletes the document referred to by the provided [DocumentReference](./firestore
 <b>Signature:</b>
 
 ```typescript
-delete(documentRef: DocumentReference<unknown>): WriteBatch;
+delete<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be deleted. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be deleted. |
 
 <b>Returns:</b>
 
@@ -77,15 +77,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: WithFieldValue<T>): WriteBatch;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: WithFieldValue<AppType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [WithFieldValue](./firestore_lite.md#withfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 
 <b>Returns:</b>
 
@@ -100,15 +100,15 @@ Writes to the document referred to by the provided [DocumentReference](./firesto
 <b>Signature:</b>
 
 ```typescript
-set<T>(documentRef: DocumentReference<T>, data: PartialWithFieldValue<T>, options: SetOptions): WriteBatch;
+set<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: PartialWithFieldValue<AppType>, options: SetOptions): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be set. |
-|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;T&gt; | An object of the fields and values for the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be set. |
+|  data | [PartialWithFieldValue](./firestore_lite.md#partialwithfieldvalue)<!-- -->&lt;AppType&gt; | An object of the fields and values for the document. |
 |  options | [SetOptions](./firestore_lite.md#setoptions) | An object to configure the set behavior. |
 
 <b>Returns:</b>
@@ -128,15 +128,15 @@ Updates fields in the document referred to by the provided [DocumentReference](.
 <b>Signature:</b>
 
 ```typescript
-update<T>(documentRef: DocumentReference<T>, data: UpdateData<T>): WriteBatch;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, data: UpdateData<DbType>): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;T&gt; | A reference to the document to be updated. |
-|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;T&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
+|  data | [UpdateData](./firestore_lite.md#updatedata)<!-- -->&lt;DbType&gt; | An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document. |
 
 <b>Returns:</b>
 
@@ -157,14 +157,14 @@ Nested fields can be update by providing dot-separated field path strings or by
 <b>Signature:</b>
 
 ```typescript
-update(documentRef: DocumentReference<unknown>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
+update<AppType, DbType extends DocumentData>(documentRef: DocumentReference<AppType, DbType>, field: string | FieldPath, value: unknown, ...moreFieldsAndValues: unknown[]): WriteBatch;
 ```
 
 ### Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;unknown&gt; | A reference to the document to be updated. |
+|  documentRef | [DocumentReference](./firestore_lite.documentreference.md#documentreference_class)<!-- -->&lt;AppType, DbType&gt; | A reference to the document to be updated. |
 |  field | string \| [FieldPath](./firestore_lite.fieldpath.md#fieldpath_class) | The first field to update. |
 |  value | unknown | The first value. |
 |  moreFieldsAndValues | unknown\[\] | Additional key value pairs. |

From b01cf18ee26961a41d9edc873332dbdc7d9c66bb Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Mon, 24 Apr 2023 14:28:01 -0400
Subject: [PATCH 9/9] yarn changeset

---
 .changeset/two-moles-sell.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 .changeset/two-moles-sell.md

diff --git a/.changeset/two-moles-sell.md b/.changeset/two-moles-sell.md
new file mode 100644
index 00000000000..52aea728d44
--- /dev/null
+++ b/.changeset/two-moles-sell.md
@@ -0,0 +1,6 @@
+---
+'@firebase/firestore': major
+'firebase': major
+---
+
+Fix typing issues with UpdateData in updateDoc(), Transaction.update(), and WriteBatch.update()