feat(firebase_auth, emulator): implement useEmulutor

Works in unit testing and when configured for e2e testing,
except for the expected test failures on disabled users, OOB and SMS
codes as the test suite needs a port to work against an empty auth
emulator vs the pre-configured data in the cloud

Prior art doing the auth tests is noted, but needs a port to javascript

Author: mikehardy

packages/firebase_auth/firebase_auth/android/src/main/java/io/flutter/plugins/firebase/auth/Constants.java

@@ -77,4 +77,6 @@ public class Constants {
   public static final String HANDLE_CODE_IN_APP = "handleCodeInApp";
   public static final String ACTION_CODE_SETTINGS = "actionCodeSettings";
   public static final String AUTO_RETRIEVED_SMS_CODE_FOR_TESTING = "autoRetrievedSmsCodeForTesting";
+  public static final String HOST = "host";
+  public static final String PORT = "port";
 }

packages/firebase_auth/firebase_auth/android/src/main/java/io/flutter/plugins/firebase/auth/FlutterFirebaseAuthPlugin.java

@@ -764,6 +764,18 @@ private Task<Void> signOut(Map<String, Object> arguments) {
         });
   }
 
+  private Task<Void> useEmulator(Map<String, Object> arguments) {
+    return Tasks.call(
+        cachedThreadPool,
+        () -> {
+          FirebaseAuth firebaseAuth = getAuth(arguments);
+          String host = (String) arguments.get(Constants.HOST);
+          int port = (int) arguments.get(Constants.PORT);
+          firebaseAuth.useEmulator(host, port);
+          return null;
+        });
+  }
+
   private Task<Map<String, Object>> verifyPasswordResetCode(Map<String, Object> arguments) {
     return Tasks.call(
         cachedThreadPool,
@@ -1196,6 +1208,9 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
       case "Auth#signOut":
         methodCallTask = signOut(call.arguments());
         break;
+      case "Auth#useEmulator":
+        methodCallTask = useEmulator(call.arguments());
+        break;
       case "Auth#verifyPasswordResetCode":
         methodCallTask = verifyPasswordResetCode(call.arguments());
         break;

packages/firebase_auth/firebase_auth/example/android/app/src/main/AndroidManifest.xml

@@ -9,6 +9,7 @@
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
     <application
+        android:usesCleartextTraffic="true"
         android:name="io.flutter.app.FlutterApplication"
         android:label="firebaseauthexample"
         android:icon="@mipmap/ic_launcher">

packages/firebase_auth/firebase_auth/example/ios/Runner/Info.plist

@@ -41,6 +41,11 @@
 	<string>$(FLUTTER_BUILD_NUMBER)</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
+	<key>NSAppTransportSecurity</key>
+	<dict>
+		<key>NSAllowsArbitraryLoads</key>
+		<true/>
+	</dict>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
 	<key>UIMainStoryboardFile</key>

packages/firebase_auth/firebase_auth/example/lib/main.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+//import 'package:firebase_auth/firebase_auth.dart'; // Only needed if you configure the Auth Emulator below
 import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_signin_button/button_builder.dart';
@@ -12,6 +13,8 @@ import './signin_page.dart';
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await Firebase.initializeApp();
+  // Uncomment this to use the auth emulator for testing
+  // await FirebaseAuth.instance.useEmulator('http://localhost:9099');
   runApp(AuthExampleApp());
 }
 

packages/firebase_auth/firebase_auth/example/test_driver/firebase_auth_e2e.dart

@@ -5,6 +5,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:drive/drive.dart' as drive;
+//import 'package:firebase_auth/firebase_auth.dart'; // only needed if you use the Auth Emulator
 import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -17,6 +18,13 @@ bool USE_EMULATOR = false;
 void testsMain() {
   setUpAll(() async {
     await Firebase.initializeApp();
+
+    // Configure the Auth test suite to use the Auth Emulator
+    // This may not be enabled until the test suite is ported to:
+    //  - have ability to create disabled users
+    //  - have ability to fetch OOB and SMS verification codes
+    // JS implementation to port to dart here: https://github.com/invertase/react-native-firebase/pull/4552/commits/4c688413cb6516ecfdbd4ea325103d0d8d8d84a8#diff-44ccd5fb03b0d9e447820032866f2494c5a400a52873f0f65518d06aedafe302
+    // await FirebaseAuth.instance.useEmulator('http://localhost:9099');
   });
 
   runInstanceTests();

packages/firebase_auth/firebase_auth/example/web/index.html

@@ -22,6 +22,9 @@
     };
     // Initialize Firebase
     firebase.initializeApp(firebaseConfig);
+
+    // Configure web auth for emulator
+    //firebase.auth().useEmulator('http://localhost:9099');
   </script>
   <script src="main.dart.js" type="application/javascript"></script>
 </body>

packages/firebase_auth/firebase_auth/ios/Classes/FLTFirebaseAuthPlugin.m

@@ -212,6 +212,8 @@ - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)flutter
     [self signInWithEmailLink:call.arguments withMethodCallResult:methodCallResult];
   } else if ([@"Auth#signOut" isEqualToString:call.method]) {
     [self signOut:call.arguments withMethodCallResult:methodCallResult];
+  } else if ([@"Auth#useEmulator" isEqualToString:call.method]) {
+    [self useEmulator:call.arguments withMethodCallResult:methodCallResult];
   } else if ([@"Auth#verifyPasswordResetCode" isEqualToString:call.method]) {
     [self verifyPasswordResetCode:call.arguments withMethodCallResult:methodCallResult];
   } else if ([@"Auth#verifyPhoneNumber" isEqualToString:call.method]) {
@@ -550,6 +552,12 @@ - (void)signOut:(id)arguments withMethodCallResult:(FLTFirebaseMethodCallResult
   }
 }
 
+- (void)useEmulator:(id)arguments withMethodCallResult:(FLTFirebaseMethodCallResult *)result {
+  FIRAuth *auth = [self getFIRAuthFromArguments:arguments];
+  [auth useEmulatorWithHost:arguments[@"host"] port:[arguments[@"port"] integerValue]];
+  result.success(nil);
+}
+
 - (void)verifyPasswordResetCode:(id)arguments
            withMethodCallResult:(FLTFirebaseMethodCallResult *)result {
   FIRAuth *auth = [self getFIRAuthFromArguments:arguments];

packages/firebase_auth/firebase_auth/lib/firebase_auth.dart

@@ -9,6 +9,7 @@ import 'dart:async';
 import 'package:firebase_core_platform_interface/firebase_core_platform_interface.dart';
 import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
 import 'package:firebase_core/firebase_core.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:meta/meta.dart';
 

packages/firebase_auth/firebase_auth/lib/src/firebase_auth.dart

@@ -83,6 +83,42 @@ class FirebaseAuth extends FirebasePluginPlatform {
     return null;
   }
 
+  /// Changes this instance to point to an Auth emulator running locally.
+  ///
+  /// Set the [origin] of the local emulator, such as "http://localhost:9099"
+  ///
+  /// Note: Must be called immediately, prior to accessing auth methods.
+  /// Do not use with production credentials as emulator traffic is not encrypted.
+  /// Returns host and port parsed from origin string, for confirmation/testing
+  Future<Map<String, dynamic>> useEmulator(String origin) async {
+    assert(origin != null);
+    assert(origin.isNotEmpty);
+
+    // Android considers localhost as 10.0.2.2 - automatically handle this for users.
+    if (defaultTargetPlatform == TargetPlatform.android) {
+      if (origin.startsWith('http://localhost')) {
+        origin = origin.replaceFirst('http://localhost', 'http://10.0.2.2');
+      } else if (origin.startsWith('http://127.0.0.1')) {
+        origin = origin.replaceFirst('http://127.0.0.1', 'http://10.0.2.2');
+      }
+    }
+
+    // Native calls take the host and port split out
+    final hostPortRegex = RegExp(r'^http:\/\/([\w\d.]+):(\d+)$');
+    if (!hostPortRegex.hasMatch(origin)) {
+      throw ArgumentError(
+          'firebase.auth().useEmulator() unable to parse host and port from url');
+    }
+    final match = hostPortRegex.firstMatch(origin);
+    final host = match.group(1);
+    final port = int.parse(match.group(2));
+
+    await _delegate.useEmulator(host, port);
+
+    // Return is used to test origin -> host/port parse
+    return {'host': host, 'port': port};
+  }
+
   /// Applies a verification code sent to the user by email or other out-of-band
   /// mechanism.
   ///

packages/firebase_auth/firebase_auth/test/firebase_auth_test.dart

@@ -168,6 +168,15 @@ void main() {
       await auth.signInAnonymously();
     });
 
+    group('emulator', () {
+      test('useEmulator()', () async {
+        Map<String, dynamic> result =
+            await auth.useEmulator('http://foo.com:31337');
+        expect(result['host'], equals('foo.com'));
+        expect(result['port'], equals(31337));
+      });
+    });
+
     group('currentUser', () {
       test('get currentUser', () {
         User user = auth.currentUser;

packages/firebase_auth/firebase_auth_platform_interface/lib/src/method_channel/method_channel_firebase_auth.dart

@@ -255,6 +255,19 @@ class MethodChannelFirebaseAuth extends FirebaseAuthPlatform {
     return this;
   }
 
+  @override
+  Future<void> useEmulator(String host, int port) async {
+    try {
+      await channel.invokeMethod<void>('Auth#useEmulator', <String, dynamic>{
+        'appName': app.name,
+        'host': host,
+        'port': port,
+      });
+    } catch (e) {
+      throw convertPlatformException(e);
+    }
+  }
+
   @override
   Future<void> applyActionCode(String code) async {
     try {

packages/firebase_auth/firebase_auth_platform_interface/lib/src/platform_interface/platform_interface_firebase_auth.dart

@@ -115,6 +115,17 @@ abstract class FirebaseAuthPlatform extends PlatformInterface {
     throw UnimplementedError("sendAuthChangesEvent() is not implemented");
   }
 
+  /// Changes this instance to point to an Auth emulator running locally.
+  ///
+  /// Set the [host] and [port] of the local emulator, such as "http://localhost"
+  /// with port 9099
+  ///
+  /// Note: Must be called immediately, prior to accessing auth methods.
+  /// Do not use with production credentials as emulator traffic is not encrypted.
+  Future<void> useEmulator(String host, int port) {
+    throw UnimplementedError("useEmulator() is not implemented");
+  }
+
   /// Applies a verification code sent to the user by email or other out-of-band
   /// mechanism.
   ///

packages/firebase_auth/firebase_auth_platform_interface/test/method_channel_tests/method_channel_firebase_auth_test.dart

@@ -831,6 +831,23 @@ void main() {
       });
     });
 
+    group('useEmulator()', () {
+      test('calls useEmulator correctly', () async {
+        await auth.useEmulator('example.com', 31337);
+        // check native method was called
+        expect(log, <Matcher>[
+          isMethodCall(
+            'Auth#useEmulator',
+            arguments: <String, dynamic>{
+              'appName': defaultFirebaseAppName,
+              'host': 'example.com',
+              'port': 31337,
+            },
+          ),
+        ]);
+      });
+    });
+
     group('verifyPasswordResetCode()', () {
       const String testCode = 'testCode';
       test('returns a successful result', () async {

packages/firebase_auth/firebase_auth_platform_interface/test/platform_interface_tests/platform_interface_auth_test.dart

@@ -401,6 +401,16 @@ void main() {
       fail('Should have thrown an [UnimplementedError]');
     });
 
+    test('throws if .useEmulator', () {
+      try {
+        firebaseAuthPlatform.useEmulator('http://localhost', 9099);
+      } on UnimplementedError catch (e) {
+        expect(e.message, equals('useEmulator() is not implemented'));
+        return;
+      }
+      fail('Should have thrown an [UnimplementedError]');
+    });
+
     test('throws if verifyPasswordResetCode()', () async {
       try {
         await firebaseAuthPlatform.verifyPasswordResetCode('test');

packages/firebase_auth/firebase_auth_web/lib/firebase_auth_web.dart

@@ -332,6 +332,18 @@ class FirebaseAuthWeb extends FirebaseAuthPlatform {
     }
   }
 
+  @override
+  Future<void> useEmulator(String host, int port) async {
+    try {
+      // The generic platform interface is with host and port split to
+      // centralize logic between android/ios native, but web takes the
+      // origin as a single string
+      await _webAuth.useEmulator('http://' + host + ':' + port.toString());
+    } catch (e) {
+      throw getFirebaseAuthException(e);
+    }
+  }
+
   @override
   Future<String> verifyPasswordResetCode(String code) async {
     try {

packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart

@@ -591,6 +591,15 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   /// Signs out the current user.
   Future signOut() => handleThenable(jsObject.signOut());
 
+  /// Configures the Auth instance to work with a local emulator
+  ///
+  /// Call with [origin] like 'http://localhost:9099'
+  ///
+  /// Note: must be called before using auth methods, do not use
+  /// with production credentials as local connections are unencrypted
+  Future useEmulator(String origin) =>
+      handleThenable(jsObject.useEmulator(origin));
+
   /// Sets the current language to the default device/browser preference.
   void useDeviceLanguage() => jsObject.useDeviceLanguage();
 

packages/firebase_auth/firebase_auth_web/lib/src/interop/auth_interop.dart

@@ -56,6 +56,7 @@ abstract class AuthJsImpl {
       AuthProviderJsImpl provider);
   external PromiseJsImpl<void> signInWithRedirect(AuthProviderJsImpl provider);
   external PromiseJsImpl<void> signOut();
+  external PromiseJsImpl<void> useEmulator(String origin);
   external void useDeviceLanguage();
   external PromiseJsImpl<String> verifyPasswordResetCode(String code);
 }