[google_sign_in] Implement Dart-based configuration and serverClientId (#6034)

Author: blaugold

packages/google_sign_in/google_sign_in_android/CHANGELOG.md

@@ -1,3 +1,12 @@
+## 6.0.0
+
+* Deprecates `clientId` and adds support for `serverClientId` instead.
+  Historically `clientId` was interpreted as `serverClientId`, but only on Android. On
+  other platforms it was interpreted as the OAuth `clientId` of the app. For backwards-compatibility
+  `clientId` will still be used as a server client ID if `serverClientId` is not provided.
+* **BREAKING CHANGES**:
+  * Adds `serverClientId` parameter to `IDelegate.init` (Java).
+
 ## 5.2.8
 
 * Suppresses `deprecation` warnings (for using Android V1 embedding).
@@ -13,4 +22,4 @@
 
 ## 5.2.5
 
-* Splits from `video_player` as a federated implementation.
+* Splits from `google_sign_in` as a federated implementation.

packages/google_sign_in/google_sign_in_android/android/src/main/java/io/flutter/plugins/googlesignin/GoogleSignInPlugin.java

@@ -8,6 +8,7 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.util.Log;
 import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.gms.auth.GoogleAuthUtil;
@@ -138,7 +139,9 @@ public void onMethodCall(MethodCall call, Result result) {
         List<String> requestedScopes = call.argument("scopes");
         String hostedDomain = call.argument("hostedDomain");
         String clientId = call.argument("clientId");
-        delegate.init(result, signInOption, requestedScopes, hostedDomain, clientId);
+        String serverClientId = call.argument("serverClientId");
+        delegate.init(
+            result, signInOption, requestedScopes, hostedDomain, clientId, serverClientId);
         break;
 
       case METHOD_SIGN_IN_SILENTLY:
@@ -194,7 +197,8 @@ public void init(
         String signInOption,
         List<String> requestedScopes,
         String hostedDomain,
-        String clientId);
+        String clientId,
+        String serverClientId);
 
     /**
      * Returns the account information for the user who is signed in to this app. If no user is
@@ -321,7 +325,8 @@ public void init(
         String signInOption,
         List<String> requestedScopes,
         String hostedDomain,
-        String clientId) {
+        String clientId,
+        String serverClientId) {
       try {
         GoogleSignInOptions.Builder optionsBuilder;
 
@@ -338,20 +343,38 @@ public void init(
             throw new IllegalStateException("Unknown signInOption");
         }
 
-        // Only requests a clientId if google-services.json was present and parsed
-        // by the google-services Gradle script.
-        // TODO(jackson): Perhaps we should provide a mechanism to override this
-        // behavior.
-        int clientIdIdentifier =
-            context
-                .getResources()
-                .getIdentifier("default_web_client_id", "string", context.getPackageName());
+        // The clientId parameter is not supported on Android.
+        // Android apps are identified by their package name and the SHA-1 of their signing key.
+        // https://developers.google.com/android/guides/client-auth
+        // https://developers.google.com/identity/sign-in/android/start#configure-a-google-api-project
         if (!Strings.isNullOrEmpty(clientId)) {
-          optionsBuilder.requestIdToken(clientId);
-          optionsBuilder.requestServerAuthCode(clientId);
-        } else if (clientIdIdentifier != 0) {
-          optionsBuilder.requestIdToken(context.getString(clientIdIdentifier));
-          optionsBuilder.requestServerAuthCode(context.getString(clientIdIdentifier));
+          if (Strings.isNullOrEmpty(serverClientId)) {
+            Log.w(
+                "google_sing_in",
+                "clientId is not supported on Android and is interpreted as serverClientId."
+                    + "Use serverClientId instead to suppress this warning.");
+            serverClientId = clientId;
+          } else {
+            Log.w("google_sing_in", "clientId is not supported on Android and is ignored.");
+          }
+        }
+
+        if (Strings.isNullOrEmpty(serverClientId)) {
+          // Only requests a clientId if google-services.json was present and parsed
+          // by the google-services Gradle script.
+          // TODO(jackson): Perhaps we should provide a mechanism to override this
+          // behavior.
+          int webClientIdIdentifier =
+              context
+                  .getResources()
+                  .getIdentifier("default_web_client_id", "string", context.getPackageName());
+          if (webClientIdIdentifier != 0) {
+            serverClientId = context.getString(webClientIdIdentifier);
+          }
+        }
+        if (!Strings.isNullOrEmpty(serverClientId)) {
+          optionsBuilder.requestIdToken(serverClientId);
+          optionsBuilder.requestServerAuthCode(serverClientId);
         }
         for (String scope : requestedScopes) {
           optionsBuilder.requestScopes(new Scope(scope));
@@ -361,7 +384,7 @@ public void init(
         }
 
         this.requestedScopes = requestedScopes;
-        signInClient = GoogleSignIn.getClient(context, optionsBuilder.build());
+        signInClient = googleSignInWrapper.getClient(context, optionsBuilder.build());
         result.success(null);
       } catch (Exception e) {
         result.error(ERROR_REASON_EXCEPTION, e.getMessage(), null);

packages/google_sign_in/google_sign_in_android/android/src/main/java/io/flutter/plugins/googlesignin/GoogleSignInWrapper.java

@@ -8,6 +8,8 @@
 import android.content.Context;
 import com.google.android.gms.auth.api.signin.GoogleSignIn;
 import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
+import com.google.android.gms.auth.api.signin.GoogleSignInClient;
+import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
 import com.google.android.gms.common.api.Scope;
 
 /**
@@ -21,6 +23,10 @@
  */
 public class GoogleSignInWrapper {
 
+  GoogleSignInClient getClient(Context context, GoogleSignInOptions options) {
+    return GoogleSignIn.getClient(context, options);
+  }
+
   GoogleSignInAccount getLastSignedInAccount(Context context) {
     return GoogleSignIn.getLastSignedInAccount(context);
   }

packages/google_sign_in/google_sign_in_android/android/src/test/java/io/flutter/plugins/googlesignin/GoogleSignInTest.java

@@ -4,6 +4,7 @@
 
 package io.flutter.plugins.googlesignin;
 
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -12,7 +13,10 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.content.res.Resources;
 import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
+import com.google.android.gms.auth.api.signin.GoogleSignInClient;
+import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
 import com.google.android.gms.common.api.Scope;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodCall;
@@ -21,6 +25,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
@@ -30,12 +35,14 @@
 
 public class GoogleSignInTest {
   @Mock Context mockContext;
+  @Mock Resources mockResources;
   @Mock Activity mockActivity;
   @Mock PluginRegistry.Registrar mockRegistrar;
   @Mock BinaryMessenger mockMessenger;
   @Spy MethodChannel.Result result;
   @Mock GoogleSignInWrapper mockGoogleSignIn;
   @Mock GoogleSignInAccount account;
+  @Mock GoogleSignInClient mockClient;
   private GoogleSignInPlugin plugin;
 
   @Before
@@ -44,6 +51,7 @@ public void setUp() {
     when(mockRegistrar.messenger()).thenReturn(mockMessenger);
     when(mockRegistrar.context()).thenReturn(mockContext);
     when(mockRegistrar.activity()).thenReturn(mockActivity);
+    when(mockContext.getResources()).thenReturn(mockResources);
     plugin = new GoogleSignInPlugin();
     plugin.initInstance(mockRegistrar.messenger(), mockRegistrar.context(), mockGoogleSignIn);
     plugin.setUpRegistrar(mockRegistrar);
@@ -195,4 +203,68 @@ public void signInThrowsWithoutActivity() {
 
     plugin.onMethodCall(new MethodCall("signIn", null), null);
   }
+
+  @Test
+  public void init_LoadsServerClientIdFromResources() {
+    final String packageName = "fakePackageName";
+    final String serverClientId = "fakeServerClientId";
+    final int resourceId = 1;
+    MethodCall methodCall = buildInitMethodCall(null, null);
+    when(mockContext.getPackageName()).thenReturn(packageName);
+    when(mockResources.getIdentifier("default_web_client_id", "string", packageName))
+        .thenReturn(resourceId);
+    when(mockContext.getString(resourceId)).thenReturn(serverClientId);
+    initAndAssertServerClientId(methodCall, serverClientId);
+  }
+
+  @Test
+  public void init_InterpretsClientIdAsServerClientId() {
+    final String clientId = "fakeClientId";
+    MethodCall methodCall = buildInitMethodCall(clientId, null);
+    initAndAssertServerClientId(methodCall, clientId);
+  }
+
+  @Test
+  public void init_ForwardsServerClientId() {
+    final String serverClientId = "fakeServerClientId";
+    MethodCall methodCall = buildInitMethodCall(null, serverClientId);
+    initAndAssertServerClientId(methodCall, serverClientId);
+  }
+
+  @Test
+  public void init_IgnoresClientIdIfServerClientIdIsProvided() {
+    final String clientId = "fakeClientId";
+    final String serverClientId = "fakeServerClientId";
+    MethodCall methodCall = buildInitMethodCall(clientId, serverClientId);
+    initAndAssertServerClientId(methodCall, serverClientId);
+  }
+
+  public void initAndAssertServerClientId(MethodCall methodCall, String serverClientId) {
+    ArgumentCaptor<GoogleSignInOptions> optionsCaptor =
+        ArgumentCaptor.forClass(GoogleSignInOptions.class);
+    when(mockGoogleSignIn.getClient(any(Context.class), optionsCaptor.capture()))
+        .thenReturn(mockClient);
+    plugin.onMethodCall(methodCall, result);
+    verify(result).success(null);
+    Assert.assertEquals(serverClientId, optionsCaptor.getValue().getServerClientId());
+  }
+
+  private static MethodCall buildInitMethodCall(String clientId, String serverClientId) {
+    return buildInitMethodCall(
+        "SignInOption.standard", Collections.<String>emptyList(), clientId, serverClientId);
+  }
+
+  private static MethodCall buildInitMethodCall(
+      String signInOption, List<String> scopes, String clientId, String serverClientId) {
+    HashMap<String, Object> arguments = new HashMap<>();
+    arguments.put("signInOption", signInOption);
+    arguments.put("scopes", scopes);
+    if (clientId != null) {
+      arguments.put("clientId", clientId);
+    }
+    if (serverClientId != null) {
+      arguments.put("serverClientId", serverClientId);
+    }
+    return new MethodCall("init", arguments);
+  }
 }

packages/google_sign_in/google_sign_in_android/example/lib/main.dart

@@ -41,14 +41,16 @@ class SignInDemoState extends State<SignInDemo> {
   }
 
   Future<void> _ensureInitialized() {
-    return _initialization ??= GoogleSignInPlatform.instance.init(
+    return _initialization ??=
+        GoogleSignInPlatform.instance.initWithParams(const SignInInitParameters(
       scopes: <String>[
         'email',
         'https://www.googleapis.com/auth/contacts.readonly',
       ],
-    )..catchError((dynamic _) {
-        _initialization = null;
-      });
+    ))
+          ..catchError((dynamic _) {
+            _initialization = null;
+          });
   }
 
   void _setUser(GoogleSignInUserData? user) {

packages/google_sign_in/google_sign_in_android/example/pubspec.yaml

@@ -16,7 +16,7 @@ dependencies:
     # The example app is bundled with the plugin so we use a path dependency on
     # the parent directory to use the current plugin's version.
     path: ../
-  google_sign_in_platform_interface: ^2.1.0
+  google_sign_in_platform_interface: ^2.2.0
   http: ^0.13.0
 
 dev_dependencies:

packages/google_sign_in/google_sign_in_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: google_sign_in_android
 description: Android implementation of the google_sign_in plugin.
 repository: https://github.com/flutter/plugins/tree/main/packages/google_sign_in/google_sign_in_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
-version: 5.2.8
+version: 6.0.0
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
@@ -20,7 +20,7 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
-  google_sign_in_platform_interface: ^2.1.0
+  google_sign_in_platform_interface: ^2.2.0
 
 dev_dependencies:
   flutter_driver:

packages/google_sign_in/google_sign_in_ios/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 5.4.0
+
+* Adds support for `serverClientId` configuration option.
+* Makes `Google-Services.info` file optional.
+
 ## 5.3.1
 
 * Suppresses warnings for pre-iOS-13 codepaths.
@@ -17,4 +22,4 @@
 
 ## 5.2.5
 
-* Splits from `video_player` as a federated implementation.
+* Splits from `google_sign_in` as a federated implementation.

packages/google_sign_in/google_sign_in_ios/example/ios/RunnerTests/GoogleSignInTests.m

@@ -96,6 +96,25 @@ - (void)testDisconnectIgnoresError {
 
 #pragma mark - Init
 
+- (void)testInitNoClientIdError {
+  // Init plugin without GoogleService-Info.plist.
+  self.plugin = [[FLTGoogleSignInPlugin alloc] initWithSignIn:self.mockSignIn
+                                  withGoogleServiceProperties:nil];
+
+  // init call does not provide a clientId.
+  FlutterMethodCall *initMethodCall = [FlutterMethodCall methodCallWithMethodName:@"init"
+                                                                        arguments:@{}];
+
+  XCTestExpectation *initExpectation =
+      [self expectationWithDescription:@"expect result returns true"];
+  [self.plugin handleMethodCall:initMethodCall
+                         result:^(FlutterError *result) {
+                           XCTAssertEqualObjects(result.code, @"missing-config");
+                           [initExpectation fulfill];
+                         }];
+  [self waitForExpectationsWithTimeout:5.0 handler:nil];
+}
+
 - (void)testInitGoogleServiceInfoPlist {
   FlutterMethodCall *initMethodCall =
       [FlutterMethodCall methodCallWithMethodName:@"init"
@@ -133,6 +152,10 @@ - (void)testInitGoogleServiceInfoPlist {
 }
 
 - (void)testInitDynamicClientIdNullDomain {
+  // Init plugin without GoogleService-Info.plist.
+  self.plugin = [[FLTGoogleSignInPlugin alloc] initWithSignIn:self.mockSignIn
+                                  withGoogleServiceProperties:nil];
+
   FlutterMethodCall *initMethodCall = [FlutterMethodCall
       methodCallWithMethodName:@"init"
                      arguments:@{@"hostedDomain" : [NSNull null], @"clientId" : @"mockClientId"}];
@@ -163,6 +186,40 @@ - (void)testInitDynamicClientIdNullDomain {
                       callback:OCMOCK_ANY]);
 }
 
+- (void)testInitDynamicServerClientIdNullDomain {
+  FlutterMethodCall *initMethodCall =
+      [FlutterMethodCall methodCallWithMethodName:@"init"
+                                        arguments:@{
+                                          @"hostedDomain" : [NSNull null],
+                                          @"serverClientId" : @"mockServerClientId"
+                                        }];
+
+  XCTestExpectation *initExpectation =
+      [self expectationWithDescription:@"expect result returns true"];
+  [self.plugin handleMethodCall:initMethodCall
+                         result:^(id result) {
+                           XCTAssertNil(result);
+                           [initExpectation fulfill];
+                         }];
+  [self waitForExpectationsWithTimeout:5.0 handler:nil];
+
+  // Initialization values used in the next sign in request.
+  FlutterMethodCall *signInMethodCall = [FlutterMethodCall methodCallWithMethodName:@"signIn"
+                                                                          arguments:nil];
+  [self.plugin handleMethodCall:signInMethodCall
+                         result:^(id r){
+                         }];
+  OCMVerify([self.mockSignIn
+       signInWithConfiguration:[OCMArg checkWithBlock:^BOOL(GIDConfiguration *configuration) {
+         return configuration.hostedDomain == nil &&
+                [configuration.serverClientID isEqualToString:@"mockServerClientId"];
+       }]
+      presentingViewController:[OCMArg isKindOfClass:[FlutterViewController class]]
+                          hint:nil
+              additionalScopes:OCMOCK_ANY
+                      callback:OCMOCK_ANY]);
+}
+
 #pragma mark - Is signed in
 
 - (void)testIsNotSignedIn {