From 351f08f453e59d94a680bb6712911ab6da41c38f Mon Sep 17 00:00:00 2001
From: Gabriel Nordeborn <gabbe.nord@gmail.com>
Date: Thu, 2 May 2024 21:32:05 +0200
Subject: [PATCH] change expectOne to raise if not exactly one item is
 encountered

---
 CHANGELOG.md                                  |   1 +
 packages/cli/src/generator.ts                 |   8 +-
 .../example/src/books/BookService__sql.res    |  32 ++---
 packages/example/src/books/books__sql.res     | 112 +++++++++---------
 .../example/src/comments/comments__sql.res    |  32 ++---
 .../src/notifications/notifications__sql.res  |  24 ++--
 6 files changed, 105 insertions(+), 104 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b0fc1fa..5a11e3b6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 - BREAKING CHANGE: `Null.t` is no longer emitted, all `null` values are autoconverted to `option`. This gives a much more idiomatic ReScript experience.
 - Emit actually runnable query in module comment for each query, instead of the original non-valid SQL query.
 - Relax requirement on providing query via `@name` comment.
+- Change `expectOne` to panic if not finding a single item.
 
 # 2.4.0
 
diff --git a/packages/cli/src/generator.ts b/packages/cli/src/generator.ts
index d77342c4..3553bdf1 100644
--- a/packages/cli/src/generator.ts
+++ b/packages/cli/src/generator.ts
@@ -397,13 +397,13 @@ module ${
     typeDec.query.name
   }Params) => promise<option<${typeDec.query.name}Result>>
   
-  /** Returns exactly 1 result. Returns \`Error\` (with an optionally provided \`errorMessage\`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises \`Exn.t\` (with an optionally provided \`errorMessage\`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     ${typeDec.query.name}Params,
     ~errorMessage: string=?
-  ) => promise<result<${typeDec.query.name}Result, string>>
+  ) => promise<${typeDec.query.name}Result>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -430,8 +430,8 @@ module ${
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
diff --git a/packages/example/src/books/BookService__sql.res b/packages/example/src/books/BookService__sql.res
index 41d92d5b..cd5ab0d3 100644
--- a/packages/example/src/books/BookService__sql.res
+++ b/packages/example/src/books/BookService__sql.res
@@ -57,13 +57,13 @@ module FindBookById: {
   @gentype
   let one: (PgTyped.Pg.Client.t, findBookByIdParams) => promise<option<findBookByIdResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     findBookByIdParams,
     ~errorMessage: string=?
-  ) => promise<result<findBookByIdResult, string>>
+  ) => promise<findBookByIdResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -84,8 +84,8 @@ module FindBookById: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -144,13 +144,13 @@ module Query1: {
   @gentype
   let one: (PgTyped.Pg.Client.t, query1Params) => promise<option<query1Result>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     query1Params,
     ~errorMessage: string=?
-  ) => promise<result<query1Result, string>>
+  ) => promise<query1Result>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -171,8 +171,8 @@ module Query1: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -227,13 +227,13 @@ module Query2: {
   @gentype
   let one: (PgTyped.Pg.Client.t, query2Params) => promise<option<query2Result>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     query2Params,
     ~errorMessage: string=?
-  ) => promise<result<query2Result, string>>
+  ) => promise<query2Result>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -254,8 +254,8 @@ module Query2: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -310,13 +310,13 @@ module Query3: {
   @gentype
   let one: (PgTyped.Pg.Client.t, query3Params) => promise<option<query3Result>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     query3Params,
     ~errorMessage: string=?
-  ) => promise<result<query3Result, string>>
+  ) => promise<query3Result>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -337,8 +337,8 @@ module Query3: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
diff --git a/packages/example/src/books/books__sql.res b/packages/example/src/books/books__sql.res
index f76cd487..85036f17 100644
--- a/packages/example/src/books/books__sql.res
+++ b/packages/example/src/books/books__sql.res
@@ -63,13 +63,13 @@ module FindBookById: {
   @gentype
   let one: (PgTyped.Pg.Client.t, findBookByIdParams) => promise<option<findBookByIdResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     findBookByIdParams,
     ~errorMessage: string=?
-  ) => promise<result<findBookByIdResult, string>>
+  ) => promise<findBookByIdResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -90,8 +90,8 @@ module FindBookById: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -148,13 +148,13 @@ module FindBookByCategory: {
   @gentype
   let one: (PgTyped.Pg.Client.t, findBookByCategoryParams) => promise<option<findBookByCategoryResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     findBookByCategoryParams,
     ~errorMessage: string=?
-  ) => promise<result<findBookByCategoryResult, string>>
+  ) => promise<findBookByCategoryResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -175,8 +175,8 @@ module FindBookByCategory: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -231,13 +231,13 @@ module FindBookNameOrRank: {
   @gentype
   let one: (PgTyped.Pg.Client.t, findBookNameOrRankParams) => promise<option<findBookNameOrRankResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     findBookNameOrRankParams,
     ~errorMessage: string=?
-  ) => promise<result<findBookNameOrRankResult, string>>
+  ) => promise<findBookNameOrRankResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -258,8 +258,8 @@ module FindBookNameOrRank: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -314,13 +314,13 @@ module FindBookUnicode: {
   @gentype
   let one: (PgTyped.Pg.Client.t, findBookUnicodeParams) => promise<option<findBookUnicodeResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     findBookUnicodeParams,
     ~errorMessage: string=?
-  ) => promise<result<findBookUnicodeResult, string>>
+  ) => promise<findBookUnicodeResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -341,8 +341,8 @@ module FindBookUnicode: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -401,13 +401,13 @@ module InsertBooks: {
   @gentype
   let one: (PgTyped.Pg.Client.t, insertBooksParams) => promise<option<insertBooksResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     insertBooksParams,
     ~errorMessage: string=?
-  ) => promise<result<insertBooksResult, string>>
+  ) => promise<insertBooksResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -428,8 +428,8 @@ module InsertBooks: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -484,13 +484,13 @@ module InsertBook: {
   @gentype
   let one: (PgTyped.Pg.Client.t, insertBookParams) => promise<option<insertBookResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     insertBookParams,
     ~errorMessage: string=?
-  ) => promise<result<insertBookResult, string>>
+  ) => promise<insertBookResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -511,8 +511,8 @@ module InsertBook: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -570,13 +570,13 @@ module UpdateBooksCustom: {
   @gentype
   let one: (PgTyped.Pg.Client.t, updateBooksCustomParams) => promise<option<updateBooksCustomResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     updateBooksCustomParams,
     ~errorMessage: string=?
-  ) => promise<result<updateBooksCustomResult, string>>
+  ) => promise<updateBooksCustomResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -597,8 +597,8 @@ module UpdateBooksCustom: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -654,13 +654,13 @@ module UpdateBooks: {
   @gentype
   let one: (PgTyped.Pg.Client.t, updateBooksParams) => promise<option<updateBooksResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     updateBooksParams,
     ~errorMessage: string=?
-  ) => promise<result<updateBooksResult, string>>
+  ) => promise<updateBooksResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -681,8 +681,8 @@ module UpdateBooks: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -737,13 +737,13 @@ module UpdateBooksRankNotNull: {
   @gentype
   let one: (PgTyped.Pg.Client.t, updateBooksRankNotNullParams) => promise<option<updateBooksRankNotNullResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     updateBooksRankNotNullParams,
     ~errorMessage: string=?
-  ) => promise<result<updateBooksRankNotNullResult, string>>
+  ) => promise<updateBooksRankNotNullResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -764,8 +764,8 @@ module UpdateBooksRankNotNull: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -824,13 +824,13 @@ module GetBooksByAuthorName: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getBooksByAuthorNameParams) => promise<option<getBooksByAuthorNameResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getBooksByAuthorNameParams,
     ~errorMessage: string=?
-  ) => promise<result<getBooksByAuthorNameResult, string>>
+  ) => promise<getBooksByAuthorNameResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -851,8 +851,8 @@ module GetBooksByAuthorName: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -904,13 +904,13 @@ module AggregateEmailsAndTest: {
   @gentype
   let one: (PgTyped.Pg.Client.t, aggregateEmailsAndTestParams) => promise<option<aggregateEmailsAndTestResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     aggregateEmailsAndTestParams,
     ~errorMessage: string=?
-  ) => promise<result<aggregateEmailsAndTestResult, string>>
+  ) => promise<aggregateEmailsAndTestResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -931,8 +931,8 @@ module AggregateEmailsAndTest: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -982,13 +982,13 @@ module GetBooks: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getBooksParams) => promise<option<getBooksResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getBooksParams,
     ~errorMessage: string=?
-  ) => promise<result<getBooksResult, string>>
+  ) => promise<getBooksResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -1009,8 +1009,8 @@ module GetBooks: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -1059,13 +1059,13 @@ module CountBooks: {
   @gentype
   let one: (PgTyped.Pg.Client.t, countBooksParams) => promise<option<countBooksResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     countBooksParams,
     ~errorMessage: string=?
-  ) => promise<result<countBooksResult, string>>
+  ) => promise<countBooksResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -1086,8 +1086,8 @@ module CountBooks: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -1137,13 +1137,13 @@ module GetBookCountries: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getBookCountriesParams) => promise<option<getBookCountriesResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getBookCountriesParams,
     ~errorMessage: string=?
-  ) => promise<result<getBookCountriesResult, string>>
+  ) => promise<getBookCountriesResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -1164,8 +1164,8 @@ module GetBookCountries: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
diff --git a/packages/example/src/comments/comments__sql.res b/packages/example/src/comments/comments__sql.res
index d3141bc1..9543d4c9 100644
--- a/packages/example/src/comments/comments__sql.res
+++ b/packages/example/src/comments/comments__sql.res
@@ -42,13 +42,13 @@ module GetAllComments: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getAllCommentsParams) => promise<option<getAllCommentsResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getAllCommentsParams,
     ~errorMessage: string=?
-  ) => promise<result<getAllCommentsResult, string>>
+  ) => promise<getAllCommentsResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -69,8 +69,8 @@ module GetAllComments: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -124,13 +124,13 @@ module GetAllCommentsByIds: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getAllCommentsByIdsParams) => promise<option<getAllCommentsByIdsResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getAllCommentsByIdsParams,
     ~errorMessage: string=?
-  ) => promise<result<getAllCommentsByIdsResult, string>>
+  ) => promise<getAllCommentsByIdsResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -151,8 +151,8 @@ module GetAllCommentsByIds: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -213,13 +213,13 @@ module InsertComment: {
   @gentype
   let one: (PgTyped.Pg.Client.t, insertCommentParams) => promise<option<insertCommentResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     insertCommentParams,
     ~errorMessage: string=?
-  ) => promise<result<insertCommentResult, string>>
+  ) => promise<insertCommentResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -240,8 +240,8 @@ module InsertComment: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -290,13 +290,13 @@ module SelectExistsTest: {
   @gentype
   let one: (PgTyped.Pg.Client.t, selectExistsTestParams) => promise<option<selectExistsTestResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     selectExistsTestParams,
     ~errorMessage: string=?
-  ) => promise<result<selectExistsTestResult, string>>
+  ) => promise<selectExistsTestResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -317,8 +317,8 @@ module SelectExistsTest: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
diff --git a/packages/example/src/notifications/notifications__sql.res b/packages/example/src/notifications/notifications__sql.res
index ad6666a5..09f480e8 100644
--- a/packages/example/src/notifications/notifications__sql.res
+++ b/packages/example/src/notifications/notifications__sql.res
@@ -49,13 +49,13 @@ module SendNotifications: {
   @gentype
   let one: (PgTyped.Pg.Client.t, sendNotificationsParams) => promise<option<sendNotificationsResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     sendNotificationsParams,
     ~errorMessage: string=?
-  ) => promise<result<sendNotificationsResult, string>>
+  ) => promise<sendNotificationsResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -76,8 +76,8 @@ module SendNotifications: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -136,13 +136,13 @@ module GetNotifications: {
   @gentype
   let one: (PgTyped.Pg.Client.t, getNotificationsParams) => promise<option<getNotificationsResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     getNotificationsParams,
     ~errorMessage: string=?
-  ) => promise<result<getNotificationsResult, string>>
+  ) => promise<getNotificationsResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -163,8 +163,8 @@ module GetNotifications: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype
@@ -220,13 +220,13 @@ module ThresholdFrogs: {
   @gentype
   let one: (PgTyped.Pg.Client.t, thresholdFrogsParams) => promise<option<thresholdFrogsResult>>
   
-  /** Returns exactly 1 result. Returns `Error` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
+  /** Returns exactly 1 result. Raises `Exn.t` (with an optionally provided `errorMessage`) if more or less than exactly 1 result is returned. */
   @gentype
   let expectOne: (
     PgTyped.Pg.Client.t,
     thresholdFrogsParams,
     ~errorMessage: string=?
-  ) => promise<result<thresholdFrogsResult, string>>
+  ) => promise<thresholdFrogsResult>
 
   /** Executes the query, but ignores whatever is returned by it. */
   @gentype
@@ -247,8 +247,8 @@ module ThresholdFrogs: {
 
   @gentype
   let expectOne = async (client, params, ~errorMessage=?) => switch await query(params, ~client) {
-  | [item] => Ok(item)
-  | _ => Error(errorMessage->Option.getOr("More or less than one item was returned"))
+  | [item] => item
+  | _ => panic(errorMessage->Option.getOr("More or less than one item was returned"))
   }
 
   @gentype