Fix container instantiation timing, IID startup.

Example/Messaging/Tests/FIRInstanceIDWithFCMTest.m

@@ -58,11 +58,10 @@ - (void)tearDown {
 }
 
 - (void)testFCMAutoInitEnabled {
-  NSString *const kFIRMessagingTestsAutoInit = @"com.messaging.test_autoInit";
-  NSUserDefaults *defaults = [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingTestsAutoInit];
+  // Use the standardUserDefaults since that's what IID expects and depends on.
+  NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
   FIRMessaging *messaging = [FIRMessagingTestUtilities messagingForTestsWithUserDefaults:defaults];
   id classMock = OCMClassMock([FIRMessaging class]);
-  OCMStub([classMock messaging]).andReturn(messaging);
   OCMStub([_mockFirebaseApp isDataCollectionDefaultEnabled]).andReturn(YES);
   messaging.autoInitEnabled = YES;
   XCTAssertTrue(

Example/Messaging/Tests/FIRMessagingTest.m

@@ -22,6 +22,7 @@
 #import <FirebaseInstanceID/FirebaseInstanceID.h>
 #import <FirebaseAnalyticsInterop/FIRAnalyticsInterop.h>
 #import <FirebaseMessaging/FIRMessaging.h>
+#import <GoogleUtilities/GULUserDefaults.h>
 
 #import "Example/Messaging/Tests/FIRMessagingTestUtilities.h"
 #import "Firebase/Messaging/FIRMessaging_Private.h"
@@ -37,6 +38,9 @@ @interface FIRMessaging ()
 @property(nonatomic, readwrite, strong) NSData *apnsTokenData;
 @property(nonatomic, readwrite, strong) FIRInstanceID *instanceID;
 
+// Expose autoInitEnabled static method for IID.
++ (BOOL)isAutoInitEnabledWithUserDefaults:(NSUserDefaults *)userDefaults;
+
 // Direct Channel Methods
 - (void)updateAutomaticClientConnection;
 - (BOOL)shouldBeConnectedAutomatically;
@@ -129,6 +133,26 @@ - (void)testAutoInitEnableGlobalDefaultFalse {
   [bundleMock stopMocking];
 }
 
+- (void)testAutoInitEnabledMatchesStaticMethod {
+  // Flag is set to YES in user defaults.
+  NSUserDefaults *defaults = self.messaging.messagingUserDefaults;
+  [defaults setObject:@YES forKey:kFIRMessagingUserDefaultsKeyAutoInitEnabled];
+
+  XCTAssertTrue(self.messaging.isAutoInitEnabled);
+  XCTAssertEqual(self.messaging.isAutoInitEnabled,
+                 [FIRMessaging isAutoInitEnabledWithUserDefaults:defaults]);
+}
+
+- (void)testAutoInitDisabledMatchesStaticMethod {
+  // Flag is set to NO in user defaults.
+  NSUserDefaults *defaults = self.messaging.messagingUserDefaults;
+  [defaults setObject:@NO forKey:kFIRMessagingUserDefaultsKeyAutoInitEnabled];
+
+  XCTAssertFalse(self.messaging.isAutoInitEnabled);
+  XCTAssertEqual(self.messaging.isAutoInitEnabled,
+                 [FIRMessaging isAutoInitEnabledWithUserDefaults:defaults]);
+}
+
 #pragma mark - Direct Channel Establishment Testing
 
 #if TARGET_OS_IOS || TARGET_OS_TV

Firebase/Core/FIRApp.m

@@ -191,6 +191,10 @@ + (void)configureWithName:(NSString *)name options:(FIROptions *)options {
     }
 
     [FIRApp addAppToAppDictionary:app];
+
+    // The FIRApp instance is ready to go, `sDefaultApp` is assigned, other SDKs are now ready to be
+    // instantiated.
+    [app.container instantiateEagerComponents];
     [FIRApp sendNotificationsToSDKs:app];
   }
 }

Firebase/Core/FIRComponentContainer.m

@@ -32,6 +32,9 @@ @interface FIRComponentContainer ()
 /// Cached instances of components that requested to be cached.
 @property(nonatomic, strong) NSMutableDictionary<NSString *, id> *cachedInstances;
 
+/// Protocols of components that have requested to be eagerly instantiated.
+@property(nonatomic, strong, nullable) NSMutableArray<Protocol *> *eagerProtocolsToInstantiate;
+
 @end
 
 @implementation FIRComponentContainer
@@ -74,6 +77,9 @@ - (instancetype)initWithApp:(FIRApp *)app registrants:(NSMutableSet<Class> *)all
 }
 
 - (void)populateComponentsFromRegisteredClasses:(NSSet<Class> *)classes forApp:(FIRApp *)app {
+  // Keep track of any components that need to eagerly instantiate after all components are added.
+  self.eagerProtocolsToInstantiate = [[NSMutableArray alloc] init];
+
   // Loop through the verified component registrants and populate the components array.
   for (Class<FIRLibrary> klass in classes) {
     // Loop through all the components being registered and store them as appropriate.
@@ -92,24 +98,39 @@ - (void)populateComponentsFromRegisteredClasses:(NSSet<Class> *)classes forApp:(
       // Store the creation block for later usage.
       self.components[protocolName] = component.creationBlock;
 
-      // Instantiate the instance if it has requested to be instantiated.
+      // Queue any protocols that should be eagerly instantiated. Don't instantiate them yet
+      // because they could depend on other components that haven't been added to the components
+      // array yet.
       BOOL shouldInstantiateEager =
           (component.instantiationTiming == FIRInstantiationTimingAlwaysEager);
       BOOL shouldInstantiateDefaultEager =
           (component.instantiationTiming == FIRInstantiationTimingEagerInDefaultApp &&
            [app isDefaultApp]);
       if (shouldInstantiateEager || shouldInstantiateDefaultEager) {
-        @synchronized(self) {
-          [self instantiateInstanceForProtocol:component.protocol
-                                     withBlock:component.creationBlock];
-        }
+        [self.eagerProtocolsToInstantiate addObject:component.protocol];
       }
     }
   }
 }
 
 #pragma mark - Instance Creation
 
+- (void)instantiateEagerComponents {
+  // After all components are registered, instantiate the ones that are requesting eager
+  // instantiation.
+  @synchronized(self) {
+    for (Protocol *protocol in self.eagerProtocolsToInstantiate) {
+      // Get an instance for the protocol, which will instantiate it since it couldn't have been
+      // cached yet. Ignore the instance coming back since we don't need it.
+      __unused id unusedInstance = [self instanceForProtocol:protocol];
+    }
+
+    // All eager instantiation is complete, empty and clear the stored property now.
+    [self.eagerProtocolsToInstantiate removeAllObjects];
+    self.eagerProtocolsToInstantiate = nil;
+  }
+}
+
 /// Instantiate an instance of a class that conforms to the specified protocol.
 /// This will:
 ///   - Call the block to create an instance if possible,

Firebase/Core/Private/FIRComponentContainerInternal.h

@@ -31,6 +31,9 @@ NS_ASSUME_NONNULL_BEGIN
 /// protocol wasn't registered, or if the instance couldn't instantiate for the provided app.
 - (nullable id)instanceForProtocol:(Protocol *)protocol NS_SWIFT_NAME(instance(for:));
 
+/// Instantiates all the components that have registered as "eager" after initialization.
+- (void)instantiateEagerComponents;
+
 /// Remove all of the cached instances stored and allow them to clean up after themselves.
 - (void)removeAllCachedInstances;
 

Firebase/InstanceID/FIRInstanceID.m

@@ -22,6 +22,7 @@
 #import <FirebaseCore/FIRLibrary.h>
 #import <FirebaseCore/FIROptions.h>
 #import <GoogleUtilities/GULAppEnvironmentUtil.h>
+#import <GoogleUtilities/GULUserDefaults.h>
 #import "FIRInstanceID+Private.h"
 #import "FIRInstanceIDAuthService.h"
 #import "FIRInstanceIDCheckinPreferences.h"
@@ -67,8 +68,8 @@
 static NSString *const kAPSEnvironmentDevelopmentValue = @"development";
 /// FIRMessaging selector that returns the current FIRMessaging auto init
 /// enabled flag.
-static NSString *const kFIRInstanceIDFCMSelectorAutoInitEnabled = @"isAutoInitEnabled";
-static NSString *const kFIRInstanceIDFCMSelectorInstance = @"messaging";
+static NSString *const kFIRInstanceIDFCMSelectorAutoInitEnabled =
+    @"isAutoInitEnabledWithUserDefaults:";
 
 static NSString *const kFIRInstanceIDAPNSTokenType = @"APNSTokenType";
 static NSString *const kFIRIIDAppReadyToConfigureSDKNotification =
@@ -77,8 +78,6 @@
 static NSString *const kFIRIIDErrorDomain = @"com.firebase.instanceid";
 static NSString *const kFIRIIDServiceInstanceID = @"InstanceID";
 
-static NSInteger const kFIRIIDErrorCodeInstanceIDFailed = -121;
-
 typedef void (^FIRInstanceIDKeyPairHandler)(FIRInstanceIDKeyPair *keyPair, NSError *error);
 
 /**
@@ -639,41 +638,41 @@ + (void)load {
 + (nonnull NSArray<FIRComponent *> *)componentsToRegister {
   FIRComponentCreationBlock creationBlock =
       ^id _Nullable(FIRComponentContainer *container, BOOL *isCacheable) {
+    // InstanceID only works with the default app.
+    if (!container.app.isDefaultApp) {
+      // Only configure for the default FIRApp.
+      FIRInstanceIDLoggerDebug(kFIRInstanceIDMessageCodeFIRApp002,
+                               @"Firebase Instance ID only works with the default app.");
+      return nil;
+    }
+
     // Ensure it's cached so it returns the same instance every time instanceID is called.
     *isCacheable = YES;
     FIRInstanceID *instanceID = [[FIRInstanceID alloc] initPrivately];
     [instanceID start];
+    [instanceID configureInstanceIDWithOptions:container.app.options];
     return instanceID;
   };
   FIRComponent *instanceIDProvider =
       [FIRComponent componentWithProtocol:@protocol(FIRInstanceIDInstanceProvider)
-                      instantiationTiming:FIRInstantiationTimingLazy
+                      instantiationTiming:FIRInstantiationTimingEagerInDefaultApp
                              dependencies:@[]
                             creationBlock:creationBlock];
   return @[ instanceIDProvider ];
 }
 
-+ (void)configureWithApp:(FIRApp *)app {
-  if (!app.isDefaultApp) {
-    // Only configure for the default FIRApp.
-    FIRInstanceIDLoggerDebug(kFIRInstanceIDMessageCodeFIRApp002,
-                             @"Firebase Instance ID only works with the default app.");
-    return;
-  }
-  [[FIRInstanceID instanceID] configureInstanceIDWithOptions:app.options app:app];
-}
-
-- (void)configureInstanceIDWithOptions:(FIROptions *)options app:(FIRApp *)firApp {
+- (void)configureInstanceIDWithOptions:(FIROptions *)options {
   NSString *GCMSenderID = options.GCMSenderID;
   if (!GCMSenderID.length) {
     FIRInstanceIDLoggerError(kFIRInstanceIDMessageCodeFIRApp000,
                              @"Firebase not set up correctly, nil or empty senderID.");
-    [FIRInstanceID exitWithReason:@"GCM_SENDER_ID must not be nil or empty." forFirebaseApp:firApp];
-    return;
+    [NSException raise:kFIRIIDErrorDomain
+                format:@"Could not configure Firebase InstanceID. GCMSenderID must not be nil or "
+                       @"empty."];
   }
 
   self.fcmSenderID = GCMSenderID;
-  self.firebaseAppID = firApp.options.googleAppID;
+  self.firebaseAppID = options.googleAppID;
 
   // FCM generates a FCM token during app start for sending push notification to device.
   // This is not needed for app extension.
@@ -682,26 +681,6 @@ - (void)configureInstanceIDWithOptions:(FIROptions *)options app:(FIRApp *)firAp
   }
 }
 
-+ (NSError *)configureErrorWithReason:(nonnull NSString *)reason {
-  NSString *description =
-      [NSString stringWithFormat:@"Configuration failed for service %@.", kFIRIIDServiceInstanceID];
-  if (!reason.length) {
-    reason = @"Unknown reason";
-  }
-
-  NSDictionary *userInfo =
-      @{NSLocalizedDescriptionKey : description, NSLocalizedFailureReasonErrorKey : reason};
-
-  return [NSError errorWithDomain:kFIRIIDErrorDomain
-                             code:kFIRIIDErrorCodeInstanceIDFailed
-                         userInfo:userInfo];
-}
-
-+ (void)exitWithReason:(nonnull NSString *)reason forFirebaseApp:(FIRApp *)firebaseApp {
-  [NSException raise:kFIRIIDErrorDomain
-              format:@"Could not configure Firebase InstanceID. %@", reason];
-}
-
 // This is used to start any operations when we receive FirebaseSDK setup notification
 // from FIRCore.
 - (void)didCompleteConfigure {
@@ -738,29 +717,20 @@ - (BOOL)isFCMAutoInitEnabled {
     return NO;
   }
 
-  // Messaging doesn't have the singleton method, auto init should be enabled since FCM exists.
-  SEL instanceSelector = NSSelectorFromString(kFIRInstanceIDFCMSelectorInstance);
-  if (![messagingClass respondsToSelector:instanceSelector]) {
-    return YES;
-  }
-
-  // Get FIRMessaging shared instance.
-  IMP messagingInstanceIMP = [messagingClass methodForSelector:instanceSelector];
-  id (*getMessagingInstance)(id, SEL) = (void *)messagingInstanceIMP;
-  id messagingInstance = getMessagingInstance(messagingClass, instanceSelector);
-
-  // Messaging doesn't have the property, auto init should be enabled since FCM exists.
+  // Messaging doesn't have the class method, auto init should be enabled since FCM exists.
   SEL autoInitSelector = NSSelectorFromString(kFIRInstanceIDFCMSelectorAutoInitEnabled);
-  if (![messagingInstance respondsToSelector:autoInitSelector]) {
+  if (![messagingClass respondsToSelector:autoInitSelector]) {
     return YES;
   }
 
-  // Get autoInitEnabled method.
-  IMP isAutoInitEnabledIMP = [messagingInstance methodForSelector:autoInitSelector];
-  BOOL (*isAutoInitEnabled)(id, SEL) = (BOOL(*)(id, SEL))isAutoInitEnabledIMP;
+  // Get the autoInitEnabled class method.
+  IMP isAutoInitEnabledIMP = [messagingClass methodForSelector:autoInitSelector];
+  BOOL (*isAutoInitEnabled)
+  (Class, SEL, GULUserDefaults *) = (BOOL(*)(id, SEL, GULUserDefaults *))isAutoInitEnabledIMP;
 
   // Check FCM's isAutoInitEnabled property.
-  return isAutoInitEnabled(messagingInstance, autoInitSelector);
+  return isAutoInitEnabled(messagingClass, autoInitSelector,
+                           [GULUserDefaults standardUserDefaults]);
 }
 
 // Actually makes InstanceID instantiate both the IID and Token-related subsystems.

Firebase/Messaging/FIRMessaging.m

@@ -541,9 +541,20 @@ - (void)setAPNSToken:(NSData *)apnsToken type:(FIRMessagingAPNSTokenType)type {
 #pragma mark - FCM
 
 - (BOOL)isAutoInitEnabled {
+  // Defer to the class method since we're just reading from regular userDefaults and we need to
+  // read this from IID without instantiating the Messaging singleton.
+  return [[self class] isAutoInitEnabledWithUserDefaults:_messagingUserDefaults];
+}
+
+/// Checks if Messaging auto-init is enabled in the user defaults instance passed in. This is
+/// exposed as a class property for IID to fetch the property without instantiating an instance of
+/// Messaging. Since Messaging can only be used with the default FIRApp, we can have one point of
+/// entry without context of which FIRApp instance is being used.
+/// ** THIS METHOD IS DEPENDED ON INTERNALLY BY IID. PLEASE DO NOT CHANGE THE SIGNATURE. **
++ (BOOL)isAutoInitEnabledWithUserDefaults:(GULUserDefaults *)userDefaults {
   // Check storage
   id isAutoInitEnabledObject =
-      [_messagingUserDefaults objectForKey:kFIRMessagingUserDefaultsKeyAutoInitEnabled];
+      [userDefaults objectForKey:kFIRMessagingUserDefaultsKeyAutoInitEnabled];
   if (isAutoInitEnabledObject) {
     return [isAutoInitEnabledObject boolValue];
   }