FIRAuthAppDelegateProxy: implementation updated to use GULAppDelegateSwizzler [WIP]

Author: maksymmalyhin

Example/Auth/Tests/FIRAuthAppDelegateProxyTests.m

@@ -20,10 +20,16 @@
 #import <objc/runtime.h>
 
 #import "FIRAuthAppDelegateProxy.h"
+#import <GoogleUtilities/GULAppDelegateSwizzler.h>
+
 #import <OCMock/OCMock.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
+@interface GULAppDelegateSwizzler (FIRAuthAppDelegateProxyTests)
++ (void)proxyAppDelegate:(id<UIApplicationDelegate>)appDelegate;
+@end
+
 /** @class FIRAuthEmptyAppDelegate
     @brief A @c UIApplicationDelegate implementation that does nothing.
  */
@@ -208,56 +214,6 @@ - (void)testSharedInstance {
   XCTAssertEqual(proxy1, proxy2);
 }
 
-/** @fn testNilApplication
-    @brief Tests that initialization fails if the application is nil.
- */
-- (void)testNilApplication {
-  XCTAssertNil([[FIRAuthAppDelegateProxy alloc] initWithApplication:nil]);
-}
-
-/** @fn testNilDelegate
-    @brief Tests that initialization fails if the application's delegate is nil.
- */
-- (void)testNilDelegate {
-  OCMExpect([_mockApplication delegate]).andReturn(nil);
-  XCTAssertNil([[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication]);
-}
-
-/** @fn testNonconformingDelegate
-    @brief Tests that initialization fails if the application's delegate does not conform to
-        @c UIApplicationDelegate protocol.
- */
-- (void)testNonconformingDelegate {
-  OCMExpect([_mockApplication delegate]).andReturn(@"abc");
-  XCTAssertNil([[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication]);
-}
-
-/** @fn testDisabledByBundleEntry
-    @brief Tests that initialization fails if the proxy is disabled by a bundle entry.
- */
-- (void)testDisabledByBundleEntry {
-  // Swizzle NSBundle's objectForInfoDictionaryKey to return @NO for the specific key.
-  Method method = class_getInstanceMethod([NSBundle class], @selector(objectForInfoDictionaryKey:));
-  __block IMP originalImplementation;
-  IMP newImplmentation = imp_implementationWithBlock(^id(id object, NSString *key) {
-    if ([key isEqualToString:@"FirebaseAppDelegateProxyEnabled"]) {
-      return @NO;
-    }
-    typedef id (*Implementation)(id object, SEL cmd, NSString *key);
-    return ((Implementation)originalImplementation)(object, @selector(objectForInfoDictionaryKey:),
-                                                    key);
-  });
-  originalImplementation = method_setImplementation(method, newImplmentation);
-
-  // Verify that initialization fails.
-  FIRAuthEmptyAppDelegate *delegate = [[FIRAuthEmptyAppDelegate alloc] init];
-  OCMStub([_mockApplication delegate]).andReturn(delegate);
-  XCTAssertNil([[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication]);
-
-  // Unswizzle.
-  imp_removeBlock(method_setImplementation(method, originalImplementation));
-}
-
 // Deprecated methods are call intentionally in tests to verify behaviors on older iOS systems.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
@@ -268,10 +224,14 @@ - (void)testDisabledByBundleEntry {
 - (void)testEmptyDelegateOneHandler {
   FIRAuthEmptyAppDelegate *delegate = [[FIRAuthEmptyAppDelegate alloc] init];
   OCMExpect([_mockApplication delegate]).andReturn(delegate);
+
+  [GULAppDelegateSwizzler proxyAppDelegate:delegate];
+
   __weak id weakProxy;
   @autoreleasepool {
-    FIRAuthAppDelegateProxy *proxy =
-        [[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication];
+    FIRAuthAppDelegateProxy *proxy = [[FIRAuthAppDelegateProxy alloc] init];
+    [GULAppDelegateSwizzler registerAppDelegateInterceptor:proxy];
+
     XCTAssertNotNil(proxy);
 
     // Verify certain methods are swizzled while others are not.
@@ -391,10 +351,13 @@ - (void)testEmptyDelegateOneHandler {
 - (void)testLegacyDelegateTwoHandlers {
   FIRAuthLegacyAppDelegate *delegate = [[FIRAuthLegacyAppDelegate alloc] init];
   OCMExpect([_mockApplication delegate]).andReturn(delegate);
+
+  [GULAppDelegateSwizzler proxyAppDelegate:delegate];
+
   __weak id weakProxy;
   @autoreleasepool {
-    FIRAuthAppDelegateProxy *proxy =
-        [[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication];
+    FIRAuthAppDelegateProxy *proxy = [[FIRAuthAppDelegateProxy alloc] init];
+    [GULAppDelegateSwizzler registerAppDelegateInterceptor:proxy];
     XCTAssertNotNil(proxy);
 
     // Verify certain methods are swizzled while others are not.
@@ -539,10 +502,13 @@ - (void)testModernDelegateWithUnaffectedInstance {
   FIRAuthModernAppDelegate *delegate = [[FIRAuthModernAppDelegate alloc] init];
   OCMExpect([_mockApplication delegate]).andReturn(delegate);
   FIRAuthModernAppDelegate *unaffectedDelegate = [[FIRAuthModernAppDelegate alloc] init];
+
+  [GULAppDelegateSwizzler proxyAppDelegate:delegate];
+
   __weak id weakProxy;
   @autoreleasepool {
-    FIRAuthAppDelegateProxy *proxy =
-        [[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication];
+    FIRAuthAppDelegateProxy *proxy = [[FIRAuthAppDelegateProxy alloc] init];
+    [GULAppDelegateSwizzler registerAppDelegateInterceptor:proxy];
     XCTAssertNotNil(proxy);
 
     // Verify certain methods are swizzled while others are not.
@@ -703,10 +669,12 @@ - (void)testModernDelegateWithUnaffectedInstance {
 - (void)testOtherLegacyDelegateHandleOpenURL {
   FIRAuthOtherLegacyAppDelegate *delegate = [[FIRAuthOtherLegacyAppDelegate alloc] init];
   OCMExpect([_mockApplication delegate]).andReturn(delegate);
+  [GULAppDelegateSwizzler proxyAppDelegate:delegate];
+
   __weak id weakProxy;
   @autoreleasepool {
-    FIRAuthAppDelegateProxy *proxy =
-        [[FIRAuthAppDelegateProxy alloc] initWithApplication:_mockApplication];
+    FIRAuthAppDelegateProxy *proxy = [[FIRAuthAppDelegateProxy alloc] init];
+    [GULAppDelegateSwizzler registerAppDelegateInterceptor:proxy];
     XCTAssertNotNil(proxy);
 
     // Verify certain methods are swizzled while others are not.

Firebase/Auth/Source/FIRAuth.m

@@ -30,6 +30,7 @@
 #import <FirebaseCore/FIRLogger.h>
 #import <FirebaseCore/FIROptions.h>
 #import <GoogleUtilities/GULAppEnvironmentUtil.h>
+#import <GoogleUtilities/GULAppDelegateSwizzler.h>
 
 #import "AuthProviders/EmailPassword/FIREmailPasswordAuthCredential.h"
 #import "FIRAdditionalUserInfo_Internal.h"
@@ -373,8 +374,12 @@ - (nullable instancetype)initWithAPIKey:(NSString *)APIKey appName:(NSString *)a
     }
     UIApplication *application = [applicationClass sharedApplication];
 
-    // Initialize the shared FIRAuthAppDelegateProxy instance in the main thread if not already.
-    [FIRAuthAppDelegateProxy sharedInstance];
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+      [GULAppDelegateSwizzler proxyOriginalDelegate];
+      [GULAppDelegateSwizzler registerAppDelegateInterceptor:[FIRAuthAppDelegateProxy sharedInstance]];
+    });
+
     #endif
 
     // Continue with the rest of initialization in the work thread.

Firebase/Auth/Source/FIRAuthAppDelegateProxy.h

@@ -55,20 +55,7 @@ NS_ASSUME_NONNULL_BEGIN
 /** @class FIRAuthAppDelegateProxy
     @brief A manager for swizzling @c UIApplicationDelegate methods.
  */
-@interface FIRAuthAppDelegateProxy : NSObject
-
-/** @fn initWithApplication
-    @brief Initialize the instance with the given @c UIApplication.
-    @returns An initialized instance, or @c nil if a proxy cannot be established.
-    @remarks This method should only be called from tests if called outside of this class.
- */
-- (nullable instancetype)initWithApplication:(nullable UIApplication *)application
-    NS_DESIGNATED_INITIALIZER;
-
-/** @fn init
-    @brief Call @c sharedInstance to get an instance of this class.
- */
-- (instancetype)init NS_UNAVAILABLE;
+@interface FIRAuthAppDelegateProxy : NSObject <UIApplicationDelegate>
 
 /** @fn addHandler:
     @brief Adds a handler for UIApplicationDelegate methods.