Refactor FIRComponentContainer to decouple from ARCore logic

This change decouples `FIRComponentContainer` from the specific `ARCore` logic by moving the exclusion rule into `FIRApp` configuration.

- Adds `excludedLibraryNames` to `FIROptions` (internal).
- Updates `FIRApp` to detect ARCore and populate `excludedLibraryNames`.
- Updates `FIRComponentContainer` to filter registrants based on `excludedLibraryNames` passed in options.
- Adds `testExcludedComponents` unit test.

Author: google-labs-jules[bot]

FirebaseCore/Sources/FIRApp.m

@@ -315,6 +315,13 @@ - (instancetype)initInstanceWithName:(NSString *)name options:(FIROptions *)opti
   if (self) {
     _name = [name copy];
     _options = [options copy];
+
+    if ([self isAppForARCore:name options:_options]) {
+      NSMutableSet<NSString *> *excluded = [NSMutableSet setWithArray:_options.excludedLibraryNames ?: @[]];
+      [excluded addObject:@"FIRAppCheckComponent"];
+      _options.excludedLibraryNames = [excluded allObjects];
+    }
+
     _options.editingLocked = YES;
     _isDefaultApp = [name isEqualToString:kFIRDefaultAppName];
     _container = [[FIRComponentContainer alloc] initWithApp:self];
@@ -435,6 +442,24 @@ - (BOOL)isDataCollectionDefaultEnabled {
 
 #pragma mark - private
 
+- (BOOL)isAppForARCore:(NSString *)appName options:(FIROptions *)options {
+  // First, check if the app name matches that of the one used by ARCore.
+  if ([appName isEqualToString:@"ARCoreFIRApp"]) {
+    // Second, check if the app's gcmSenderID matches that of ARCore. This
+    // prevents false positives in the unlikely event a 3P Firebase app is
+    // named `ARCoreFIRApp`.
+    const char *p1 = "406756";
+    const char *p2 = "893798";
+    const char gcmSenderIDKey[27] = {p1[0],  p2[0],  p1[1],  p2[1],  p1[2],  p2[2], p1[3],
+                                     p2[3],  p1[4],  p2[4],  p1[5],  p2[5],  p1[6], p2[6],
+                                     p1[7],  p2[7],  p1[8],  p2[8],  p1[9],  p2[9], p1[10],
+                                     p2[10], p1[11], p2[11], p1[12], p2[12], '\0'};
+    NSString *gcmSenderID = [NSString stringWithUTF8String:gcmSenderIDKey];
+    return [options.GCMSenderID isEqualToString:gcmSenderID];
+  }
+  return NO;
+}
+
 + (void)sendNotificationsToSDKs:(FIRApp *)app {
   // TODO: Remove this notification once all SDKs are registered with `FIRCoreConfigurable`.
   NSNumber *isDefaultApp = [NSNumber numberWithBool:app.isDefaultApp];

FirebaseCore/Sources/FIRComponentContainer.m

@@ -64,16 +64,6 @@ + (void)registerAsComponentRegistrant:(Class<FIRLibrary>)klass
 
 - (instancetype)initWithApp:(FIRApp *)app {
   NSMutableSet<Class> *componentRegistrants = sFIRComponentRegistrants;
-  // If the app being created is for the ARCore SDK, remove the App Check
-  // component (if it exists) since it does not support App Check.
-  if ([self isAppForARCore:app]) {
-    Class klass = NSClassFromString(@"FIRAppCheckComponent");
-    if (klass && [sFIRComponentRegistrants containsObject:klass]) {
-      componentRegistrants = [componentRegistrants mutableCopy];
-      [componentRegistrants removeObject:klass];
-    }
-  }
-
   return [self initWithApp:app registrants:componentRegistrants];
 }
 
@@ -84,6 +74,17 @@ - (instancetype)initWithApp:(FIRApp *)app registrants:(NSMutableSet<Class> *)all
     _cachedInstances = [NSMutableDictionary<NSString *, id> dictionary];
     _components = [NSMutableDictionary<NSString *, FIRComponentCreationBlock> dictionary];
 
+    NSArray<NSString *> *excludedLibraryNames = app.options.excludedLibraryNames;
+    if (excludedLibraryNames.count > 0) {
+      allRegistrants = [allRegistrants mutableCopy];
+      for (NSString *libraryName in excludedLibraryNames) {
+        Class klass = NSClassFromString(libraryName);
+        if (klass) {
+          [allRegistrants removeObject:klass];
+        }
+      }
+    }
+
     [self populateComponentsFromRegisteredClasses:allRegistrants forApp:app];
   }
   return self;
@@ -229,24 +230,6 @@ - (void)removeAllComponents {
 
 #pragma mark - Helpers
 
-- (BOOL)isAppForARCore:(FIRApp *)app {
-  // First, check if the app name matches that of the one used by ARCore.
-  if ([app.name isEqualToString:@"ARCoreFIRApp"]) {
-    // Second, check if the app's gcmSenderID matches that of ARCore. This
-    // prevents false positives in the unlikely event a 3P Firebase app is
-    // named `ARCoreFIRApp`.
-    const char *p1 = "406756";
-    const char *p2 = "893798";
-    const char gcmSenderIDKey[27] = {p1[0],  p2[0],  p1[1],  p2[1],  p1[2],  p2[2], p1[3],
-                                     p2[3],  p1[4],  p2[4],  p1[5],  p2[5],  p1[6], p2[6],
-                                     p1[7],  p2[7],  p1[8],  p2[8],  p1[9],  p2[9], p1[10],
-                                     p2[10], p1[11], p2[11], p1[12], p2[12], '\0'};
-    NSString *gcmSenderID = [NSString stringWithUTF8String:gcmSenderIDKey];
-    return [app.options.GCMSenderID isEqualToString:gcmSenderID];
-  }
-  return NO;
-}
-
 @end
 
 NS_ASSUME_NONNULL_END

FirebaseCore/Sources/FIROptions.m

@@ -30,6 +30,9 @@
 // The key to locate the project identifier in the plist file.
 NSString *const kFIRProjectID = @"PROJECT_ID";
 
+// The key to locate the excluded library names in the options dictionary.
+NSString *const kFIRExcludedLibraryNames = @"EXCLUDED_LIBRARY_NAMES";
+
 NSString *const kFIRIsMeasurementEnabled = @"IS_MEASUREMENT_ENABLED";
 NSString *const kFIRIsAnalyticsCollectionEnabled = @"FIREBASE_ANALYTICS_COLLECTION_ENABLED";
 NSString *const kFIRIsAnalyticsCollectionDeactivated = @"FIREBASE_ANALYTICS_COLLECTION_DEACTIVATED";
@@ -320,6 +323,15 @@ - (void)setAppGroupID:(NSString *)appGroupID {
   _appGroupID = [appGroupID copy];
 }
 
+- (NSArray<NSString *> *)excludedLibraryNames {
+  return self.optionsDictionary[kFIRExcludedLibraryNames];
+}
+
+- (void)setExcludedLibraryNames:(NSArray<NSString *> *)excludedLibraryNames {
+  [self checkEditingLocked];
+  _optionsDictionary[kFIRExcludedLibraryNames] = [excludedLibraryNames copy];
+}
+
 #pragma mark - Equality
 
 - (BOOL)isEqual:(id)object {

FirebaseCore/Sources/FIROptionsInternal.h

@@ -70,4 +70,9 @@
  */
 @property(nonatomic, getter=isEditingLocked) BOOL editingLocked;
 
+/**
+ * A list of class names to exclude from component registration.
+ */
+@property(nonatomic, copy, nullable) NSArray<NSString *> *excludedLibraryNames;
+
 @end

FirebaseCore/Tests/Unit/FIRComponentContainerTest.m

@@ -245,4 +245,29 @@ - (FIRComponentContainer *)containerWithRegistrants:(NSArray<Class> *)registrant
   return container;
 }
 
+- (void)testExcludedComponents {
+  // Create options with excluded component.
+  FIROptions *options = [[FIROptions alloc] initWithGoogleAppID:kGoogleAppID
+                                                    GCMSenderID:kGCMSenderID];
+  options.excludedLibraryNames = @[ @"FIRTestClass" ];
+
+  _hostApp = [[FIRApp alloc] initInstanceWithName:@"fake_app_excluded" options:options];
+
+  NSMutableSet<Class> *allRegistrants = [NSMutableSet<Class> set];
+  [FIRComponentContainer registerAsComponentRegistrant:[FIRTestClass class] inSet:allRegistrants];
+  [FIRComponentContainer registerAsComponentRegistrant:[FIRTestClassCached class] inSet:allRegistrants];
+
+  // Initialize container with the app (which has the options).
+  FIRComponentContainer *container = [[FIRComponentContainer alloc] initWithApp:_hostApp registrants:allRegistrants];
+  _hostApp.container = container;
+
+  // FIRTestClass should be excluded, so FIRTestProtocol should not be registered.
+  id<FIRTestProtocol> instance = FIR_COMPONENT(FIRTestProtocol, container);
+  XCTAssertNil(instance, @"Instance should be nil because the component was excluded.");
+
+  // FIRTestClassCached should still be there.
+  id<FIRTestProtocolCached> cachedInstance = FIR_COMPONENT(FIRTestProtocolCached, container);
+  XCTAssertNotNil(cachedInstance, @"Cached instance should not be nil.");
+}
+
 @end