[google_sign_in] Add macOS support (#4962)

Adds macOS support to `google_sign_in_ios` by moving the existing source to `darwin/`, adjusting it somewhat to be macOS-compatible, and enabling `sharedDarwinSource` in the podspec.

Unlike previous cases of code sharing, this doesn't rename the package to be something more generic, since when we do that the name is based on the underlying SDK, and the SDK is still mostly called "Google Sign-In for iOS", so I don't think there's a better name to give it at the moment.

Most of flutter/flutter#46157
(Once this lands, there will be a follow-up PR to update the app-facing package to endorse it and list it in the README.)

.ci/scripts/update_pods.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+set -e
+
+# Ensure that the pods repos are up to date, since analyze will not check for
+# the latest versions of pods, so can use stale Flutter or FlutterMacOS pods
+# for analysis otherwise.
+pod repo update --verbose

.ci/targets/macos_check_podspecs.yaml

@@ -2,6 +2,9 @@ tasks:
   - name: prepare tool
     script: .ci/scripts/prepare_tool.sh
     infra_step: true # Note infra steps failing prevents "always" from running.
+  - name: update pods repo
+    script: .ci/scripts/update_pods.sh
+    infra_step: true # Note infra steps failing prevents "always" from running.
   - name: validate iOS and macOS podspecs
     script: script/tool_runner.sh
     args: ["podspec-check"]

packages/google_sign_in/google_sign_in_ios/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 5.7.0
 
-* Updates minimum supported SDK version to Flutter 3.10/Dart 3.0.
+* Adds support for macOS.
+* Updates minimum supported SDK version to Flutter 3.16/Dart 3.2.
 
 ## 5.6.5
 

packages/google_sign_in/google_sign_in_ios/README.md

@@ -1,6 +1,6 @@
 # google\_sign\_in\_ios
 
-The iOS implementation of [`google_sign_in`][1].
+The iOS and macOS implementation of [`google_sign_in`][1].
 
 ## Usage
 
@@ -11,6 +11,21 @@ so you do not need to add it to your `pubspec.yaml`.
 However, if you `import` this package to use any of its APIs directly, you
 should add it to your `pubspec.yaml` as usual.
 
+### macOS setup
+
+The GoogleSignIn SDK requires keychain sharing to be enabled, by [adding the
+following entitlements](https://docs.flutter.dev/platform-integration/macos/building#entitlements-and-the-app-sandbox):
+
+```xml
+    <key>keychain-access-groups</key>
+    <array>
+        <string>$(AppIdentifierPrefix)com.google.GIDSignIn</string>
+    </array>
+```
+
+Without this step, the plugin will throw a `keychain error` `PlatformException`
+when trying to sign in.
+
 [1]: https://pub.dev/packages/google_sign_in
 [2]: https://flutter.dev/docs/development/packages-and-plugins/developing-packages#endorsed-federated-plugin
 

packages/google_sign_in/google_sign_in_ios/ios/Classes/FLTGoogleSignInPlugin.h → packages/google_sign_in/google_sign_in_ios/darwin/Classes/FLTGoogleSignInPlugin.h

@@ -2,10 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#if TARGET_OS_OSX
+#import <FlutterMacOS/FlutterMacOS.h>
+#else
 #import <Flutter/Flutter.h>
+#endif
 
 #import "messages.g.h"
 
 @interface FLTGoogleSignInPlugin : NSObject <FlutterPlugin, FSIGoogleSignInApi>
-
+- (instancetype)init NS_UNAVAILABLE;
 @end

packages/google_sign_in/google_sign_in_ios/ios/Classes/FLTGoogleSignInPlugin.m → packages/google_sign_in/google_sign_in_ios/darwin/Classes/FLTGoogleSignInPlugin.m

@@ -50,32 +50,37 @@ @interface FLTGoogleSignInPlugin ()
 // The contents of GoogleService-Info.plist, if it exists.
 @property(strong, nullable) NSDictionary<NSString *, id> *googleServiceProperties;
 
-// Redeclared as not a designated initializer.
-- (instancetype)init;
+// The plugin registrar, for querying views.
+@property(strong, nonnull) id<FlutterPluginRegistrar> registrar;
 
 @end
 
 @implementation FLTGoogleSignInPlugin
 
 + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
-  FLTGoogleSignInPlugin *instance = [[FLTGoogleSignInPlugin alloc] init];
+  FLTGoogleSignInPlugin *instance = [[FLTGoogleSignInPlugin alloc] initWithRegistrar:registrar];
   [registrar addApplicationDelegate:instance];
   FSIGoogleSignInApiSetup(registrar.messenger, instance);
 }
 
-- (instancetype)init {
-  return [self initWithSignIn:GIDSignIn.sharedInstance];
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
+  return [self initWithSignIn:GIDSignIn.sharedInstance registrar:registrar];
 }
 
-- (instancetype)initWithSignIn:(GIDSignIn *)signIn {
-  return [self initWithSignIn:signIn withGoogleServiceProperties:loadGoogleServiceInfo()];
+- (instancetype)initWithSignIn:(GIDSignIn *)signIn
+                     registrar:(NSObject<FlutterPluginRegistrar> *)registrar {
+  return [self initWithSignIn:signIn
+                    registrar:registrar
+      googleServiceProperties:loadGoogleServiceInfo()];
 }
 
 - (instancetype)initWithSignIn:(GIDSignIn *)signIn
-    withGoogleServiceProperties:(nullable NSDictionary<NSString *, id> *)googleServiceProperties {
+                     registrar:(NSObject<FlutterPluginRegistrar> *)registrar
+       googleServiceProperties:(nullable NSDictionary<NSString *, id> *)googleServiceProperties {
   self = [super init];
   if (self) {
     _signIn = signIn;
+    _registrar = registrar;
     _googleServiceProperties = googleServiceProperties;
 
     // On the iOS simulator, we get "Broken pipe" errors after sign-in for some
@@ -88,9 +93,19 @@ - (instancetype)initWithSignIn:(GIDSignIn *)signIn
 
 #pragma mark - <FlutterPlugin> protocol
 
+#if TARGET_OS_IOS
 - (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary *)options {
   return [self.signIn handleURL:url];
 }
+#else
+- (BOOL)handleOpenURLs:(NSArray<NSURL *> *)urls {
+  BOOL handled = NO;
+  for (NSURL *url in urls) {
+    handled = handled || [self.signIn handleURL:url];
+  }
+  return handled;
+}
+#endif
 
 #pragma mark - FSIGoogleSignInApi
 
@@ -134,23 +149,21 @@ - (void)signInWithCompletion:(nonnull void (^)(FSIUserData *_Nullable,
       self.signIn.configuration = self.configuration;
     }
 
-    [self.signIn signInWithPresentingViewController:[self topViewController]
-                                               hint:nil
-                                   additionalScopes:self.requestedScopes.allObjects
-                                         completion:^(GIDSignInResult *_Nullable signInResult,
-                                                      NSError *_Nullable error) {
-                                           GIDGoogleUser *user;
-                                           NSString *serverAuthCode;
-                                           if (signInResult) {
-                                             user = signInResult.user;
-                                             serverAuthCode = signInResult.serverAuthCode;
-                                           }
-
-                                           [self didSignInForUser:user
-                                               withServerAuthCode:serverAuthCode
-                                                       completion:completion
-                                                            error:error];
-                                         }];
+    [self signInWithHint:nil
+        additionalScopes:self.requestedScopes.allObjects
+              completion:^(GIDSignInResult *_Nullable signInResult, NSError *_Nullable error) {
+                GIDGoogleUser *user;
+                NSString *serverAuthCode;
+                if (signInResult) {
+                  user = signInResult.user;
+                  serverAuthCode = signInResult.serverAuthCode;
+                }
+
+                [self didSignInForUser:user
+                    withServerAuthCode:serverAuthCode
+                            completion:completion
+                                 error:error];
+              }];
   } @catch (NSException *e) {
     completion(nil, [FlutterError errorWithCode:@"google_sign_in" message:e.reason details:e.name]);
     [e raise];
@@ -196,51 +209,67 @@ - (void)requestScopes:(nonnull NSArray<NSString *> *)scopes
                                           message:@"No account to grant scopes."
                                           details:nil]);
     }
-    [currentUser addScopes:requestedScopes.allObjects
-        presentingViewController:[self topViewController]
-                      completion:^(GIDSignInResult *_Nullable signInResult,
-                                   NSError *_Nullable addedScopeError) {
-                        BOOL granted = NO;
-                        FlutterError *error = nil;
-
-                        if ([addedScopeError.domain isEqualToString:kGIDSignInErrorDomain] &&
-                            addedScopeError.code == kGIDSignInErrorCodeMismatchWithCurrentUser) {
-                          error =
-                              [FlutterError errorWithCode:@"mismatch_user"
-                                                  message:@"There is an operation on a previous "
-                                                          @"user. Try signing in again."
-                                                  details:nil];
-                        } else if ([addedScopeError.domain isEqualToString:kGIDSignInErrorDomain] &&
-                                   addedScopeError.code ==
-                                       kGIDSignInErrorCodeScopesAlreadyGranted) {
-                          // Scopes already granted, report success.
-                          granted = YES;
-                        } else if (signInResult.user) {
-                          NSSet<NSString *> *grantedScopes =
-                              [NSSet setWithArray:signInResult.user.grantedScopes];
-                          granted = [requestedScopes isSubsetOfSet:grantedScopes];
-                        }
-                        completion(error == nil ? @(granted) : nil, error);
-                      }];
+    [self addScopes:requestedScopes.allObjects
+         completion:^(GIDSignInResult *_Nullable signInResult, NSError *_Nullable addedScopeError) {
+           BOOL granted = NO;
+           FlutterError *error = nil;
+
+           if ([addedScopeError.domain isEqualToString:kGIDSignInErrorDomain] &&
+               addedScopeError.code == kGIDSignInErrorCodeMismatchWithCurrentUser) {
+             error = [FlutterError errorWithCode:@"mismatch_user"
+                                         message:@"There is an operation on a previous "
+                                                 @"user. Try signing in again."
+                                         details:nil];
+           } else if ([addedScopeError.domain isEqualToString:kGIDSignInErrorDomain] &&
+                      addedScopeError.code == kGIDSignInErrorCodeScopesAlreadyGranted) {
+             // Scopes already granted, report success.
+             granted = YES;
+           } else if (signInResult.user) {
+             NSSet<NSString *> *grantedScopes =
+                 [NSSet setWithArray:signInResult.user.grantedScopes];
+             granted = [requestedScopes isSubsetOfSet:grantedScopes];
+           }
+           completion(error == nil ? @(granted) : nil, error);
+         }];
   } @catch (NSException *e) {
     completion(nil, [FlutterError errorWithCode:@"request_scopes" message:e.reason details:e.name]);
   }
 }
 
-#pragma mark - <GIDSignInUIDelegate> protocol
+#pragma mark - private methods
 
-- (void)signIn:(GIDSignIn *)signIn presentViewController:(UIViewController *)viewController {
-  UIViewController *rootViewController =
-      [UIApplication sharedApplication].delegate.window.rootViewController;
-  [rootViewController presentViewController:viewController animated:YES completion:nil];
+// Wraps the iOS and macOS sign in display methods.
+- (void)signInWithHint:(nullable NSString *)hint
+      additionalScopes:(nullable NSArray<NSString *> *)additionalScopes
+            completion:(nullable void (^)(GIDSignInResult *_Nullable signInResult,
+                                          NSError *_Nullable error))completion {
+#if TARGET_OS_OSX
+  [self.signIn signInWithPresentingWindow:self.registrar.view.window
+                                     hint:hint
+                         additionalScopes:additionalScopes
+                               completion:completion];
+#else
+  [self.signIn signInWithPresentingViewController:[self topViewController]
+                                             hint:hint
+                                 additionalScopes:additionalScopes
+                                       completion:completion];
+#endif
 }
 
-- (void)signIn:(GIDSignIn *)signIn dismissViewController:(UIViewController *)viewController {
-  [viewController dismissViewControllerAnimated:YES completion:nil];
+// Wraps the iOS and macOS scope addition methods.
+- (void)addScopes:(NSArray<NSString *> *)scopes
+       completion:(nullable void (^)(GIDSignInResult *_Nullable signInResult,
+                                     NSError *_Nullable error))completion {
+  GIDGoogleUser *currentUser = self.signIn.currentUser;
+#if TARGET_OS_OSX
+  [currentUser addScopes:scopes presentingWindow:self.registrar.view.window completion:completion];
+#else
+  [currentUser addScopes:scopes
+      presentingViewController:[self topViewController]
+                    completion:completion];
+#endif
 }
 
-#pragma mark - private methods
-
 /// @return @c nil if GoogleService-Info.plist not found and clientId is not provided.
 - (GIDConfiguration *)configurationWithClientIdArgument:(id)clientIDArg
                                  serverClientIdArgument:(id)serverClientIDArg
@@ -299,6 +328,8 @@ - (void)didSignInForUser:(GIDGoogleUser *)user
   }
 }
 
+#if TARGET_OS_IOS
+
 - (UIViewController *)topViewController {
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
@@ -337,4 +368,6 @@ - (UIViewController *)topViewControllerFromViewController:(UIViewController *)vi
   return viewController;
 }
 
+#endif
+
 @end

packages/google_sign_in/google_sign_in_ios/ios/Classes/FLTGoogleSignInPlugin_Test.h → packages/google_sign_in/google_sign_in_ios/darwin/Classes/FLTGoogleSignInPlugin_Test.h

@@ -29,12 +29,17 @@ NS_ASSUME_NONNULL_BEGIN
 // sign in, sign out, and requesting additional scopes.
 @property(strong, readonly) GIDSignIn *signIn;
 
+/// Inject @c FlutterPluginRegistrar for testing.
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar;
+
 /// Inject @c GIDSignIn for testing.
-- (instancetype)initWithSignIn:(GIDSignIn *)signIn;
+- (instancetype)initWithSignIn:(GIDSignIn *)signIn
+                     registrar:(NSObject<FlutterPluginRegistrar> *)registrar;
 
 /// Inject @c GIDSignIn and @c googleServiceProperties for testing.
 - (instancetype)initWithSignIn:(GIDSignIn *)signIn
-    withGoogleServiceProperties:(nullable NSDictionary<NSString *, id> *)googleServiceProperties
+                     registrar:(NSObject<FlutterPluginRegistrar> *)registrar
+       googleServiceProperties:(nullable NSDictionary<NSString *, id> *)googleServiceProperties
     NS_DESIGNATED_INITIALIZER;
 
 @end