Handle UISceneDelegate changes in Auth

Firebase/Auth/Source/Auth/FIRAuth.m

@@ -231,7 +231,11 @@ + (FIRActionCodeOperation)actionCodeOperationForRequestType:(NSString *)requestT
 #pragma mark - FIRAuth
 
 #if TARGET_OS_IOS
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
+@interface FIRAuth () <UIApplicationDelegate, UISceneDelegate, FIRLibrary, FIRComponentLifecycleMaintainer>
+#else
 @interface FIRAuth () <UIApplicationDelegate, FIRLibrary, FIRComponentLifecycleMaintainer>
+#endif
 #else
 @interface FIRAuth () <FIRLibrary, FIRComponentLifecycleMaintainer>
 #endif
@@ -1387,7 +1391,17 @@ - (BOOL)canHandleURL:(NSURL *)URL {
   });
   return result;
 }
-#endif
+
+#pragma mark - UISceneDelegate
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
+- (void)scene:(UIScene *)scene openURLContexts:(NSSet<UIOpenURLContext *> *)URLContexts API_AVAILABLE(ios(13.0)) {
+  for (UIOpenURLContext *urlContext in URLContexts) {
+    NSURL *url = [urlContext URL];
+    [self canHandleURL:url];
+  }
+}
+#endif  // __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
+#endif  // TARGET_OS_IOS
 
 #pragma mark - Internal Methods
 

GoogleUtilities/AppDelegateSwizzler/GULAppDelegateSwizzler.m

@@ -31,6 +31,11 @@ typedef BOOL (*GULRealOpenURLSourceApplicationAnnotationIMP)(
 typedef BOOL (*GULRealOpenURLOptionsIMP)(
     id, SEL, GULApplication *, NSURL *, NSDictionary<NSString *, id> *);
 
+#if UISCENE_SUPPORTED
+API_AVAILABLE(ios(13.0), tvos(13.0))
+typedef void (*GULOpenURLContextsIMP)(id, SEL, UIScene *, NSSet<UIOpenURLContext *> *);
+#endif  // UISCENE_SUPPORTED
+
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wstrict-prototypes"
 typedef void (*GULRealHandleEventsForBackgroundURLSessionIMP)(
@@ -289,6 +294,20 @@ + (void)proxyOriginalDelegate {
     id<GULApplicationDelegate> originalDelegate =
         [GULAppDelegateSwizzler sharedApplication].delegate;
     [GULAppDelegateSwizzler proxyAppDelegate:originalDelegate];
+
+#if UISCENE_SUPPORTED
+    if (@available(iOS 13.0, tvOS 13.0, *)) {
+      if (![GULAppDelegateSwizzler isAppDelegateProxyEnabled]) {
+        return;
+      } else {
+        [[NSNotificationCenter defaultCenter]
+            addObserver:self
+               selector:@selector(handleSceneWillConnectToNotification:)
+                   name:UISceneWillConnectNotification
+                 object:nil];
+      }
+    }
+#endif  // UISCENE_SUPPORTED
   });
 }
 
@@ -682,6 +701,15 @@ + (void)notifyInterceptorsWithMethodSelector:(SEL)methodSelector
   }];
 }
 
+#if UISCENE_SUPPORTED
++ (void)handleSceneWillConnectToNotification:(NSNotification *)notification {
+  if (@available(iOS 13.0, tvOS 13.0, *)) {
+    UIScene *scene = (UIScene *)notification.object;
+    [GULAppDelegateSwizzler proxySceneDelegate:scene];
+  }
+}
+#endif  // UISCENE_SUPPORTED
+
 // The methods below are donor methods which are added to the dynamic subclass of the App Delegate.
 // They are called within the scope of the real App Delegate so |self| does not refer to the
 // GULAppDelegateSwizzler instance but the real App Delegate instance.
@@ -761,6 +789,40 @@ - (BOOL)application:(GULApplication *)application
 
 #endif  // TARGET_OS_IOS
 
+#pragma mark - [Donor Methods] UISceneDelegate URL handler
+
+#if UISCENE_SUPPORTED
+- (void)scene:(UIScene *)scene
+    openURLContexts:(NSSet<UIOpenURLContext *> *)URLContexts API_AVAILABLE(ios(13.0), tvos(13.0)) {
+  if (@available(iOS 13.0, tvOS 13.0, *)) {
+    SEL methodSelector = @selector(scene:openURLContexts:);
+    // Call the real implementation if the real App Delegate has any.
+    NSValue *openURLContextsIMPPointer =
+        [GULAppDelegateSwizzler originalImplementationForSelector:methodSelector object:self];
+    GULOpenURLContextsIMP openURLContextsIMP = [openURLContextsIMPPointer pointerValue];
+
+    // This is needed for the library to be warning free on iOS versions < 9.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability"
+    [GULAppDelegateSwizzler
+        notifyInterceptorsWithMethodSelector:methodSelector
+                                    callback:^(id<GULApplicationDelegate> interceptor) {
+                                      if ([interceptor
+                                              conformsToProtocol:@protocol(UISceneDelegate)]) {
+                                        id<UISceneDelegate> sceneInterceptor =
+                                            (id<UISceneDelegate>)interceptor;
+                                        [sceneInterceptor scene:scene openURLContexts:URLContexts];
+                                      }
+                                    }];
+#pragma clang diagnostic pop
+
+    if (openURLContextsIMP) {
+      openURLContextsIMP(self, methodSelector, scene, URLContexts);
+    }
+  }
+}
+#endif  // UISCENE_SUPPORTED
+
 #pragma mark - [Donor Methods] Network overridden handler methods
 
 #if TARGET_OS_IOS || TARGET_OS_TV
@@ -1002,6 +1064,89 @@ + (void)proxyAppDelegate:(id<GULApplicationDelegate>)appDelegate {
   }
 }
 
+#if UISCENE_SUPPORTED
++ (void)proxySceneDelegate:(UIScene *)scene {
+  Class realClass = [scene.delegate class];
+
+  // Skip proxying if the class has a prefix of kGULAppDelegatePrefix, which means it has been
+  // proxied before.
+  if ([NSStringFromClass(realClass) hasPrefix:kGULAppDelegatePrefix]) {
+    return;
+  }
+
+  NSString *classNameWithPrefix =
+      [kGULAppDelegatePrefix stringByAppendingString:NSStringFromClass(realClass)];
+  NSString *newClassName =
+      [NSString stringWithFormat:@"%@-%@", classNameWithPrefix, [NSUUID UUID].UUIDString];
+
+  if (NSClassFromString(newClassName)) {
+    GULLogError(kGULLoggerSwizzler, NO,
+                [NSString stringWithFormat:@"I-SWZ%06ld",
+                                           (long)kGULSwizzlerMessageCodeAppDelegateSwizzling005],
+                @"Cannot create a proxy for App Delegate. Subclass already exists. Original Class: "
+                @"%@, subclass: %@",
+                NSStringFromClass(realClass), newClassName);
+    return;
+  }
+
+  // Register the new class as subclass of the real one. Do not allocate more than the real class
+  // size.
+  Class sceneDelegateSubClass = objc_allocateClassPair(realClass, newClassName.UTF8String, 0);
+  if (sceneDelegateSubClass == Nil) {
+    GULLogError(kGULLoggerSwizzler, NO,
+                [NSString stringWithFormat:@"I-SWZ%06ld",
+                                           (long)kGULSwizzlerMessageCodeAppDelegateSwizzling006],
+                @"Cannot create a proxy for App Delegate. Subclass already exists. Original Class: "
+                @"%@, subclass: Nil",
+                NSStringFromClass(realClass));
+    return;
+  }
+
+  NSMutableDictionary<NSString *, NSValue *> *realImplementationsBySelector =
+      [[NSMutableDictionary alloc] init];
+
+  // For scene:openURLContexts:
+  SEL openURLContextsSEL = @selector(scene:openURLContexts:);
+  [self proxyDestinationSelector:openURLContextsSEL
+      implementationsFromSourceSelector:openURLContextsSEL
+                              fromClass:[GULAppDelegateSwizzler class]
+                                toClass:sceneDelegateSubClass
+                              realClass:realClass
+       storeDestinationImplementationTo:realImplementationsBySelector];
+
+  // Store original implementations to a fake property of the original delegate.
+  objc_setAssociatedObject(scene.delegate, &kGULRealIMPBySelectorKey,
+                           [realImplementationsBySelector copy], OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+  objc_setAssociatedObject(scene.delegate, &kGULRealClassKey, realClass,
+                           OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+
+  // The subclass size has to be exactly the same size with the original class size. The subclass
+  // cannot have more ivars/properties than its superclass since it will cause an offset in memory
+  // that can lead to overwriting the isa of an object in the next frame.
+  if (class_getInstanceSize(realClass) != class_getInstanceSize(sceneDelegateSubClass)) {
+    GULLogError(kGULLoggerSwizzler, NO,
+                [NSString stringWithFormat:@"I-SWZ%06ld",
+                                           (long)kGULSwizzlerMessageCodeAppDelegateSwizzling007],
+                @"Cannot create subclass of App Delegate, because the created subclass is not the "
+                @"same size. %@",
+                NSStringFromClass(realClass));
+    NSAssert(NO, @"Classes must be the same size to swizzle isa");
+    return;
+  }
+
+  // Make the newly created class to be the subclass of the real App Delegate class.
+  objc_registerClassPair(sceneDelegateSubClass);
+  if (object_setClass(scene.delegate, sceneDelegateSubClass)) {
+    GULLogDebug(kGULLoggerSwizzler, NO,
+                [NSString stringWithFormat:@"I-SWZ%06ld",
+                                           (long)kGULSwizzlerMessageCodeAppDelegateSwizzling008],
+                @"Successfully created App Delegate Proxy automatically. To disable the "
+                @"proxy, set the flag %@ to NO (Boolean) in the Info.plist",
+                [GULAppDelegateSwizzler correctAppDelegateProxyKey]);
+  }
+}
+#endif  // UISCENE_SUPPORTED
+
 #pragma mark - Methods to print correct debug logs
 
 + (NSString *)correctAppDelegateProxyKey {

GoogleUtilities/AppDelegateSwizzler/Internal/GULAppDelegateSwizzler_Private.h

@@ -18,6 +18,10 @@
 #import <GoogleUtilities/GULAppDelegateSwizzler.h>
 #import <GoogleUtilities/GULMutableDictionary.h>
 
+#if ((TARGET_OS_IOS || TARGET_OS_TV) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= 130000))
+#define UISCENE_SUPPORTED 1
+#endif
+
 @class GULApplication;
 
 NS_ASSUME_NONNULL_BEGIN
@@ -50,6 +54,17 @@ NS_ASSUME_NONNULL_BEGIN
  */
 + (id<GULApplicationDelegate>)originalDelegate;
 
+#if UISCENE_SUPPORTED
+
+/** ISA Swizzles the given appDelegate as the original app delegate would be.
+ *
+ *  @param scene The scene whose delegate needs to be isa swizzled. This should conform to the
+ *      scene delegate protocol.
+ */
++ (void)proxySceneDelegate:(UIScene *)scene API_AVAILABLE(ios(13.0), tvos(13.0));
+
+#endif  // UISCENE_SUPPORTED
+
 @end
 
 NS_ASSUME_NONNULL_END

GoogleUtilities/Example/Tests/Swizzler/GULAppDelegateSwizzlerTest.m

@@ -280,6 +280,17 @@ - (BOOL)application:(GULApplication *)application
 
 @end
 
+#pragma mark - Scene Delegate
+
+#if ((TARGET_OS_IOS || TARGET_OS_TV) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= 130000))
+API_AVAILABLE(ios(13.0), tvos(13.0))
+@interface GULTestSceneDelegate : NSObject <UISceneDelegate>
+@end
+
+@implementation GULTestSceneDelegate
+@end
+#endif
+
 @interface GULAppDelegateSwizzlerTest : XCTestCase
 @property(nonatomic, strong) id mockSharedApplication;
 @end
@@ -1301,4 +1312,60 @@ - (void)testAppDelegateIsProxiedIncludingAPNSMethodsWhenEnabled {
   XCTAssertNotEqualObjects([originalAppDelegate class], originalAppDelegateClass);
 }
 
+#pragma mark - Test UISceneDelegate proxy
+
+#if ((TARGET_OS_IOS || TARGET_OS_TV) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= 130000))
+
+- (void)testProxySceneDelegate {
+  if (@available(iOS 13, tvOS 13, *)) {
+    GULTestSceneDelegate *realSceneDelegate = [[GULTestSceneDelegate alloc] init];
+    id mockSharedScene = OCMClassMock([UIScene class]);
+    OCMStub([mockSharedScene delegate]).andReturn(realSceneDelegate);
+    size_t sizeBefore = class_getInstanceSize([GULTestSceneDelegate class]);
+
+    Class realSceneDelegateClassBefore = [realSceneDelegate class];
+
+    [GULAppDelegateSwizzler proxySceneDelegate:mockSharedScene];
+
+    XCTAssertTrue([realSceneDelegate isKindOfClass:[GULTestSceneDelegate class]]);
+
+    NSString *newClassName = NSStringFromClass([realSceneDelegate class]);
+    XCTAssertTrue([newClassName hasPrefix:@"GUL_"]);
+    // It is no longer GULTestSceneDelegate class instance.
+    XCTAssertFalse([realSceneDelegate isMemberOfClass:[GULTestSceneDelegate class]]);
+
+    size_t sizeAfter = class_getInstanceSize([realSceneDelegate class]);
+
+    // Class size must stay the same.
+    XCTAssertEqual(sizeBefore, sizeAfter);
+
+    // After being proxied, it should be able to respond to the required method selector.
+    XCTAssertTrue([realSceneDelegate respondsToSelector:@selector(scene:openURLContexts:)]);
+
+    // Make sure that the class has changed.
+    XCTAssertNotEqualObjects([realSceneDelegate class], realSceneDelegateClassBefore);
+  }
+}
+
+- (void)testProxyProxiedSceneDelegate {
+  if (@available(iOS 13, tvOS 13, *)) {
+    GULTestSceneDelegate *realSceneDelegate = [[GULTestSceneDelegate alloc] init];
+    id mockSharedScene = OCMClassMock([UIScene class]);
+    OCMStub([mockSharedScene delegate]).andReturn(realSceneDelegate);
+
+    // Proxy the scene delegate for the 1st time.
+    [GULAppDelegateSwizzler proxySceneDelegate:mockSharedScene];
+
+    Class realSceneDelegateClassBefore = [realSceneDelegate class];
+
+    // Proxy the scene delegate for the 2nd time.
+    [GULAppDelegateSwizzler proxySceneDelegate:mockSharedScene];
+
+    // Make sure that the class isn't changed.
+    XCTAssertEqualObjects([realSceneDelegate class], realSceneDelegateClassBefore);
+  }
+}
+
+#endif
+
 @end