Prevent Messaging and IID singleton usage during tests.

Example/Firebase.xcodeproj/project.pbxproj

@@ -617,6 +617,7 @@
 		EDD53E2A211B08A300376BFF /* FIRComponentTestUtilities.m in Sources */ = {isa = PBXBuildFile; fileRef = EDD53E28211B08A300376BFF /* FIRComponentTestUtilities.m */; };
 		EDD53E2B211B08A300376BFF /* FIRComponentTestUtilities.m in Sources */ = {isa = PBXBuildFile; fileRef = EDD53E28211B08A300376BFF /* FIRComponentTestUtilities.m */; };
 		EDD53E2C211B08A300376BFF /* FIRComponentTestUtilities.m in Sources */ = {isa = PBXBuildFile; fileRef = EDD53E28211B08A300376BFF /* FIRComponentTestUtilities.m */; };
+		EDF5242C21EA37AA00BB24C6 /* FIRMessagingTestUtilities.m in Sources */ = {isa = PBXBuildFile; fileRef = EDF5242B21EA364600BB24C6 /* FIRMessagingTestUtilities.m */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -1345,6 +1346,8 @@
 		EDD53E24211A442D00376BFF /* FIRAuthInteropFake.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = FIRAuthInteropFake.m; path = Shared/FIRAuthInteropFake.m; sourceTree = "<group>"; };
 		EDD53E28211B08A300376BFF /* FIRComponentTestUtilities.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = FIRComponentTestUtilities.m; path = Shared/FIRComponentTestUtilities.m; sourceTree = "<group>"; };
 		EDD53E29211B08A300376BFF /* FIRComponentTestUtilities.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = FIRComponentTestUtilities.h; path = Shared/FIRComponentTestUtilities.h; sourceTree = "<group>"; };
+		EDF5242A21EA364600BB24C6 /* FIRMessagingTestUtilities.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FIRMessagingTestUtilities.h; sourceTree = "<group>"; };
+		EDF5242B21EA364600BB24C6 /* FIRMessagingTestUtilities.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FIRMessagingTestUtilities.m; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -2340,6 +2343,8 @@
 				DE9315D71E8738B70083EDBF /* FIRMessagingTestNotificationUtilities.m */,
 				DE37C63A2163D5F30025D03E /* FIRMessagingAnalyticsTest.m */,
 				DE9315D81E8738B70083EDBF /* Info.plist */,
+				EDF5242A21EA364600BB24C6 /* FIRMessagingTestUtilities.h */,
+				EDF5242B21EA364600BB24C6 /* FIRMessagingTestUtilities.m */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
@@ -4419,6 +4424,7 @@
 				DE9315F91E8738E60083EDBF /* FIRMessagingFakeConnection.m in Sources */,
 				DE9316021E8738E60083EDBF /* FIRMessagingServiceTest.m in Sources */,
 				DE9315FE1E8738E60083EDBF /* FIRMessagingRegistrarTest.m in Sources */,
+				EDF5242C21EA37AA00BB24C6 /* FIRMessagingTestUtilities.m in Sources */,
 				DE9316031E8738E60083EDBF /* FIRMessagingSyncMessageManagerTest.m in Sources */,
 				DE9315FF1E8738E60083EDBF /* FIRMessagingRemoteNotificationsProxyTest.m in Sources */,
 				DEF61BFD216E8B1100A738D4 /* FIRMessagingReceiverTest.m in Sources */,

Example/Messaging/Tests/FIRMessagingLinkHandlingTest.m

@@ -21,10 +21,12 @@
 #import "FIRMessaging.h"
 #import "FIRMessagingConstants.h"
 #import "FIRMessagingTestNotificationUtilities.h"
+#import "FIRMessagingTestUtilities.h"
+
+NSString *const kFIRMessagingTestsLinkHandlingSuiteName = @"com.messaging.test_linkhandling";
 
 @interface FIRMessaging ()
 
-+ (FIRMessaging *)messagingForTests;
 - (NSURL *)linkURLFromMessage:(NSDictionary *)message;
 
 @end
@@ -39,10 +41,13 @@ @implementation FIRMessagingLinkHandlingTest
 
 - (void)setUp {
   [super setUp];
-  _messaging = [FIRMessaging messagingForTests];
+
+  NSUserDefaults *defaults = [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingTestsLinkHandlingSuiteName];
+  _messaging = [FIRMessagingTestUtilities messagingForTestsWithUserDefaults:defaults];
 }
 
 - (void)tearDown {
+  [self.messaging.messagingUserDefaults removePersistentDomainForName:kFIRMessagingTestsLinkHandlingSuiteName];
   _messaging = nil;
   [super tearDown];
 }

Example/Messaging/Tests/FIRMessagingReceiverTest.m

@@ -22,10 +22,9 @@
 
 #import "FIRMessaging.h"
 #import "FIRMessaging_Private.h"
+#import "FIRMessagingTestUtilities.h"
 
-@interface FIRMessaging ()
-+ (FIRMessaging *)messagingForTests;
-@end
+NSString *const kFIRMessagingTestsReceiverSuiteName = @"com.messaging.test_receiverTest";
 
 @interface FIRMessagingReceiverTest : XCTestCase
 @property(nonatomic, readonly, strong) FIRMessaging *messaging;
@@ -36,9 +35,15 @@ @implementation FIRMessagingReceiverTest
 - (void)setUp {
   [super setUp];
 
-  _messaging = [FIRMessaging messagingForTests];
-  [[NSUserDefaults standardUserDefaults]
-      removePersistentDomainForName:[NSBundle mainBundle].bundleIdentifier];
+  NSUserDefaults *defaults = [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingTestsReceiverSuiteName];
+  _messaging = [FIRMessagingTestUtilities messagingForTestsWithUserDefaults:defaults];
+}
+
+- (void)tearDown {
+  [self.messaging.messagingUserDefaults removePersistentDomainForName:kFIRMessagingTestsReceiverSuiteName];
+  _messaging = nil;
+
+  [super tearDown];
 }
 
 - (void)testUseMessagingDelegate {

Example/Messaging/Tests/FIRMessagingServiceTest.m

@@ -22,6 +22,7 @@
 #import "FIRMessaging.h"
 #import "FIRMessagingClient.h"
 #import "FIRMessagingPubSub.h"
+#import "FIRMessagingTestUtilities.h"
 #import "FIRMessagingTopicsCommon.h"
 #import "InternalHeaders/FIRMessagingInternalUtilities.h"
 #import "NSError+FIRMessaging.h"
@@ -31,8 +32,9 @@
     @"yUTTzK6dhIvLqzqqCSabaa4TQVM0pGTmF6r7tmMHPe6VYiGMHuCwJFgj5v97xl78sUNMLwuPPhoci8z_"
     @"QGlCrTbxCFGzEUfvA3fGpGgIVQU2W6";
 
+NSString *const kFIRMessagingTestsServiceSuiteName = @"com.messaging.test_serviceTest";
+
 @interface FIRMessaging () <FIRMessagingClientDelegate>
-+ (FIRMessaging *)messagingForTests;
 @property(nonatomic, readwrite, strong) FIRMessagingClient *client;
 @property(nonatomic, readwrite, strong) FIRMessagingPubSub *pubsub;
 @property(nonatomic, readwrite, strong) NSString *defaultFcmToken;
@@ -55,14 +57,17 @@ @interface FIRMessagingServiceTest : XCTestCase {
 @implementation FIRMessagingServiceTest
 
 - (void)setUp {
-  _messaging = [FIRMessaging messagingForTests];
+  NSUserDefaults *defaults = [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingTestsServiceSuiteName];
+  _messaging = [FIRMessagingTestUtilities messagingForTestsWithUserDefaults:defaults];
   _messaging.defaultFcmToken = kFakeToken;
   _mockPubSub = OCMPartialMock(_messaging.pubsub);
   [_mockPubSub setClient:nil];
   [super setUp];
 }
 
 - (void)tearDown {
+  [_messaging.messagingUserDefaults removePersistentDomainForName:kFIRMessagingTestsServiceSuiteName];
+  _messaging = nil;
   [_mockPubSub stopMocking];
   [super tearDown];
 }

Example/Messaging/Tests/FIRMessagingTest.m

@@ -20,25 +20,22 @@
 
 #import <FirebaseCore/FIRAppInternal.h>
 #import <FirebaseInstanceID/FirebaseInstanceID.h>
+#import <FirebaseAnalyticsInterop/FIRAnalyticsInterop.h>
 
 #import "FIRMessaging.h"
 #import "FIRMessaging_Private.h"
+#import "FIRMessagingTestUtilities.h"
 
 extern NSString *const kFIRMessagingFCMTokenFetchAPNSOption;
 
-@interface FIRInstanceID (ExposedForTest)
-
-+ (FIRInstanceID *)instanceIDForTests;
-
-@end
+/// The NSUserDefaults domain for testing.
+NSString *const kFIRMessagingDefaultsTestDomain = @"com.messaging.tests";
 
 @interface FIRMessaging ()
-+ (FIRMessaging *)messagingForTests;
 
 @property(nonatomic, readwrite, strong) NSString *defaultFcmToken;
 @property(nonatomic, readwrite, strong) NSData *apnsTokenData;
 @property(nonatomic, readwrite, strong) FIRInstanceID *instanceID;
-@property(nonatomic, readwrite, strong) NSUserDefaults *messagingUserDefaults;
 
 // Direct Channel Methods
 - (void)updateAutomaticClientConnection;
@@ -59,8 +56,12 @@ @implementation FIRMessagingTest
 
 - (void)setUp {
   [super setUp];
-  _messaging = [FIRMessaging messagingForTests];
-  _messaging.instanceID = [FIRInstanceID instanceIDForTests];
+
+  // Create the messaging instance with all the necessary dependencies.
+  NSUserDefaults *defaults =
+      [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingDefaultsTestDomain];
+  _messaging = [FIRMessagingTestUtilities messagingForTestsWithUserDefaults:defaults];
+
   _mockFirebaseApp = OCMClassMock([FIRApp class]);
    OCMStub([_mockFirebaseApp defaultApp]).andReturn(_mockFirebaseApp);
   _mockInstanceID = OCMPartialMock(self.messaging.instanceID);
@@ -69,12 +70,14 @@ - (void)setUp {
 }
 
 - (void)tearDown {
+  [self.messaging.messagingUserDefaults removePersistentDomainForName:kFIRMessagingDefaultsTestDomain];
   self.messaging.shouldEstablishDirectChannel = NO;
   self.messaging.defaultFcmToken = nil;
   self.messaging.apnsTokenData = nil;
   [_mockMessaging stopMocking];
   [_mockInstanceID stopMocking];
   [_mockFirebaseApp stopMocking];
+  _messaging = nil;
   [super tearDown];
 }
 

Example/Messaging/Tests/FIRMessagingTestUtilities.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "FIRMessaging.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FIRMessaging (TestUtilities)
+// Surface the user defaults instance to clean up after tests.
+@property(nonatomic, strong) NSUserDefaults *messagingUserDefaults;
+@end
+
+@interface FIRMessagingTestUtilities : NSObject
+
+/**
+ Creates an instance of FIRMessaging to use with tests, and will instantiate a new instance of
+ InstanceID.
+
+ Note: This does not create a FIRApp instance and call `configureWithApp:`. If required, it's up to
+       each test to do so.
+
+ @param userDefaults The user defaults to be used for Messaging.
+ @return An instance of FIRMessaging with everything initialized.
+ */
++ (FIRMessaging *)messagingForTestsWithUserDefaults:(NSUserDefaults *)userDefaults;
+
+@end
+
+NS_ASSUME_NONNULL_END

Example/Messaging/Tests/FIRMessagingTestUtilities.m

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FIRMessagingTestUtilities.h"
+
+#import <FirebaseAnalyticsInterop/FIRAnalyticsInterop.h>
+#import <FirebaseInstanceID/FirebaseInstanceID.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FIRInstanceID (ExposedForTest)
+
+/// Private initializer to avoid singleton usage.
+- (FIRInstanceID *)initPrivately;
+
+/// Starts fetching and configuration of InstanceID. This is necessary after the `initPrivately`
+/// call.
+- (void)start;
+
+@end
+
+@interface FIRMessaging (ExposedForTest)
+
+/// Surface internal initializer to avoid singleton usage during tests.
+- (instancetype)initWithAnalytics:(nullable id<FIRAnalyticsInterop>)analytics
+                   withInstanceID:(FIRInstanceID *)instanceID
+                 withUserDefaults:(NSUserDefaults *)defaults;
+
+/// Kicks off required calls for some messaging tests.
+- (void)start;
+
+@end
+
+@implementation FIRMessagingTestUtilities
+
++ (FIRMessaging *)messagingForTestsWithUserDefaults:(NSUserDefaults *)userDefaults {
+  // Create the messaging instance with all the necessary dependencies.
+  FIRInstanceID *instanceID = [[FIRInstanceID alloc] initPrivately];
+  [instanceID start];
+
+  // Create the messaging instance and call `start`.
+  FIRMessaging *messaging = [[FIRMessaging alloc] initWithAnalytics:nil
+                                                     withInstanceID:instanceID
+                                                   withUserDefaults:userDefaults];
+  [messaging start];
+  return messaging;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END

Firebase/Messaging/FIRMessaging.m

@@ -162,32 +162,19 @@ @interface FIRMessaging () <FIRMessagingInstanceProvider, FIRLibrary>
 
 @implementation FIRMessaging
 
-// File static to support InstanceID tests that call [FIRMessaging messaging] after
-// [FIRMessaging messagingForTests].
-static FIRMessaging *sMessaging;
-
 + (FIRMessaging *)messaging {
-  if (sMessaging != nil) {
-    return sMessaging;
-  }
   FIRApp *defaultApp = [FIRApp defaultApp];  // Missing configure will be logged here.
-  id<FIRMessagingInstanceProvider> messaging =
+  id<FIRMessagingInstanceProvider> instance =
       FIR_COMPONENT(FIRMessagingInstanceProvider, defaultApp.container);
 
+  // We know the instance coming from the container is a FIRMessaging instance, cast it and move on.
+  FIRMessaging *messaging = (FIRMessaging *)instance;
+
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{
-    [(FIRMessaging *)messaging start];
+    [messaging start];
   });
-  sMessaging = (FIRMessaging *)messaging;
-  return sMessaging;
-}
-
-+ (FIRMessaging *)messagingForTests {
-  sMessaging = [[FIRMessaging alloc] initWithAnalytics:nil
-                                        withInstanceID:[FIRInstanceID instanceID]
-                                      withUserDefaults:[NSUserDefaults standardUserDefaults]];
-  [sMessaging start];
-  return sMessaging;
+  return messaging;
 }
 
 - (instancetype)initWithAnalytics:(nullable id<FIRAnalyticsInterop>)analytics
@@ -322,7 +309,7 @@ - (void)setupNotificationListeners {
 }
 
 - (void)setupReceiver {
-  self.receiver = [[FIRMessagingReceiver alloc] init];
+  self.receiver = [[FIRMessagingReceiver alloc] initWithUserDefaults:self.messagingUserDefaults];
   self.receiver.delegate = self;
 }
 

Firebase/Messaging/FIRMessagingReceiver.h

@@ -17,18 +17,28 @@
 #import "FIRMessagingDataMessageManager.h"
 #import "FIRMessaging.h"
 
+NS_ASSUME_NONNULL_BEGIN
+
 @class FIRMessagingReceiver;
 @protocol FIRMessagingReceiverDelegate <NSObject>
 
-- (void)receiver:(nonnull FIRMessagingReceiver *)receiver
-      receivedRemoteMessage:(nonnull FIRMessagingRemoteMessage *)remoteMessage;
+- (void)receiver:(FIRMessagingReceiver *)receiver
+      receivedRemoteMessage:(FIRMessagingRemoteMessage *)remoteMessage;
 
 @end
 
 @interface FIRMessagingReceiver : NSObject <FIRMessagingDataMessageManagerDelegate>
 
+/// Default initializer for creating the messaging receiver.
+- (instancetype)initWithUserDefaults:(NSUserDefaults *)defaults NS_DESIGNATED_INITIALIZER;
+
+/// Use `initWithUserDefaults:` instead.
+- (instancetype)init NS_UNAVAILABLE;
+
 @property(nonatomic, weak, nullable) id<FIRMessagingReceiverDelegate> delegate;
 /// Whether to use direct channel for direct channel message callback handler in all iOS versions.
 @property(nonatomic, assign) BOOL useDirectChannel;
 
 @end
+
+NS_ASSUME_NONNULL_END