feat(auth): Enable resumable SignIn

packages/auth/src/providers/cognito/utils/signInStore.ts

@@ -1,6 +1,8 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+import { ConsoleLogger, syncSessionStorage } from '@aws-amplify/core';
+
 import { CognitoAuthSignInDetails } from '../types';
 
 import { ChallengeName } from './clients/CognitoIdentityProvider/types';
@@ -27,6 +29,18 @@ type Store<State, Action> = (reducer: Reducer<State, Action>) => {
 
 type Reducer<State, Action> = (state: State, action: Action) => State;
 
+const logger = new ConsoleLogger('Auth signInStore');
+
+// Minutes until stored session invalidates
+const EXPIRATION_MINUTES = 3;
+const MS_TO_EXPIRY = 1000 * 60 * EXPIRATION_MINUTES;
+const signInStateKeys: Record<string, string> = {
+	username: 'CognitoSignInState.username',
+	challengeName: 'CognitoSignInState.challengeName',
+	signInSession: 'CognitoSignInState.signInSession',
+	expiry: 'CognitoSignInState.expiry',
+};
+
 const signInReducer: Reducer<SignInState, SignInAction> = (state, action) => {
 	switch (action.type) {
 		case 'SET_SIGN_IN_SESSION':
@@ -49,22 +63,70 @@ const signInReducer: Reducer<SignInState, SignInAction> = (state, action) => {
 				username: action.value,
 			};
 		case 'SET_INITIAL_STATE':
-			return defaultState();
+			return setInitialState();
 		default:
 			return state;
 	}
 };
 
-function defaultState(): SignInState {
+const isExpired = (expiryDate: string): boolean => {
+	const expiryTimestamp = Number(expiryDate);
+	const currentTimestamp = Date.now();
+
+	return expiryTimestamp <= currentTimestamp;
+};
+
+const clearPersistedSignInState = (keys: Record<string, string>) => {
+	for (const key in keys) {
+		syncSessionStorage.removeItem(key);
+	}
+};
+
+// Clear saved sign in states from both memory and Synced Session Storage
+export function cleanActiveSignInState(): void {
+	signInStore.dispatch({ type: 'SET_INITIAL_STATE' });
+	clearSignInStateKeysFromSessionStorage();
+}
+
+// Clear stored values for sign in state keys in Synced Session Storage
+export function clearSignInStateKeysFromSessionStorage(): void {
+	clearPersistedSignInState(signInStateKeys);
+}
+
+const getDefaultState = (): SignInState => ({
+	username: undefined,
+	challengeName: undefined,
+	signInSession: undefined,
+});
+
+// Hydrate signInStore from Synced Session Storage
+const setInitialState = (): SignInState => {
+	const expiry = syncSessionStorage.getItem(signInStateKeys.expiry) as string;
+	if (isExpired(expiry)) {
+		logger.warn('Sign-in session expired');
+		clearPersistedSignInState(signInStateKeys);
+
+		return getDefaultState();
+	}
+
+	const username =
+		syncSessionStorage.getItem(signInStateKeys.username) ?? undefined;
+
+	const challengeName = (syncSessionStorage.getItem(
+		signInStateKeys.challengeName,
+	) ?? undefined) as ChallengeName;
+	const signInSession =
+		syncSessionStorage.getItem(signInStateKeys.signInSession) ?? undefined;
+
 	return {
-		username: undefined,
-		challengeName: undefined,
-		signInSession: undefined,
+		username,
+		challengeName,
+		signInSession,
 	};
-}
+};
 
 const createStore: Store<SignInState, SignInAction> = reducer => {
-	let currentState = reducer(defaultState(), { type: 'SET_INITIAL_STATE' });
+	let currentState = reducer(getDefaultState(), { type: 'SET_INITIAL_STATE' });
 
 	return {
 		getState: () => currentState,
@@ -81,8 +143,21 @@ export function setActiveSignInState(state: SignInState): void {
 		type: 'SET_SIGN_IN_STATE',
 		value: state,
 	});
-}
 
-export function cleanActiveSignInState(): void {
-	signInStore.dispatch({ type: 'SET_INITIAL_STATE' });
+	// Save the local state into Synced Session Storage
+	persistSignInState(syncSessionStorage, state);
 }
+
+const persistSignInState = (
+	storage = syncSessionStorage,
+	{
+		challengeName = '' as ChallengeName,
+		signInSession = '',
+		username = '',
+	}: SignInState,
+) => {
+	storage.setItem(signInStateKeys.username, username);
+	storage.setItem(signInStateKeys.challengeName, challengeName);
+	storage.setItem(signInStateKeys.signInSession, signInSession);
+	storage.setItem(signInStateKeys.expiry, String(Date.now() + MS_TO_EXPIRY));
+};

packages/aws-amplify/src/utils/index.ts

@@ -14,6 +14,7 @@ export {
 	CookieStorage,
 	defaultStorage,
 	sessionStorage,
+	syncSessionStorage,
 	sharedInMemoryStorage,
 	KeyValueStorageInterface,
 } from '@aws-amplify/core';

packages/core/src/index.ts

@@ -59,6 +59,7 @@ export {
 	CookieStorage,
 	defaultStorage,
 	sessionStorage,
+	syncSessionStorage,
 	sharedInMemoryStorage,
 } from './storage';
 export { KeyValueStorageInterface } from './types';

packages/core/src/storage/SyncKeyValueStorage.ts

@@ -0,0 +1,58 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import { PlatformNotSupportedError } from '../errors';
+import { SyncSessionStorageInterface } from '../types';
+
+/**
+ * @internal
+ */
+export class SyncKeyValueStorage implements SyncSessionStorageInterface {
+	storage?: Storage;
+
+	constructor(storage?: Storage) {
+		this.storage = storage;
+	}
+
+	/**
+	 * This is used to set a specific item in storage
+	 * @param {string} key - the key for the item
+	 * @param {object} value - the value
+	 * @returns {string} value that was set
+	 */
+	setItem(key: string, value: string) {
+		if (!this.storage) throw new PlatformNotSupportedError();
+		this.storage.setItem(key, value);
+	}
+
+	/**
+	 * This is used to get a specific key from storage
+	 * @param {string} key - the key for the item
+	 * This is used to clear the storage
+	 * @returns {string} the data item
+	 */
+	getItem(key: string) {
+		if (!this.storage) throw new PlatformNotSupportedError();
+
+		return this.storage.getItem(key);
+	}
+
+	/**
+	 * This is used to remove an item from storage
+	 * @param {string} key - the key being set
+	 * @returns {string} value - value that was deleted
+	 */
+	removeItem(key: string) {
+		if (!this.storage) throw new PlatformNotSupportedError();
+		this.storage.removeItem(key);
+	}
+
+	/**
+	 * This is used to clear the storage
+	 * @returns {string} nothing
+	 */
+	clear() {
+		if (!this.storage) throw new PlatformNotSupportedError();
+		this.storage.clear();
+	}
+}

packages/core/src/storage/SyncSessionStorage.ts

@@ -0,0 +1,14 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import { SyncKeyValueStorage } from './SyncKeyValueStorage';
+import { getSessionStorageWithFallback } from './utils';
+
+/**
+ * @internal
+ */
+export class SyncSessionStorage extends SyncKeyValueStorage {
+	constructor() {
+		super(getSessionStorageWithFallback());
+	}
+}

packages/core/src/storage/index.ts

@@ -5,9 +5,11 @@ import { DefaultStorage } from './DefaultStorage';
 import { InMemoryStorage } from './InMemoryStorage';
 import { KeyValueStorage } from './KeyValueStorage';
 import { SessionStorage } from './SessionStorage';
+import { SyncSessionStorage } from './SyncSessionStorage';
 
 export { CookieStorage } from './CookieStorage';
 
 export const defaultStorage = new DefaultStorage();
 export const sessionStorage = new SessionStorage();
+export const syncSessionStorage = new SyncSessionStorage();
 export const sharedInMemoryStorage = new KeyValueStorage(new InMemoryStorage());

packages/core/src/types/storage.ts

@@ -21,3 +21,10 @@ export interface CookieStorageData {
 	secure?: boolean;
 	sameSite?: SameSite;
 }
+
+export interface SyncSessionStorageInterface {
+	setItem(key: string, value: string): void;
+	getItem(key: string): string | null;
+	removeItem(key: string): void;
+	clear(): void;
+}