really try to fix the unit tests

Author: themiswang

FirebaseRemoteConfig/Sources/FIRRemoteConfigComponent.h

@@ -47,6 +47,9 @@ NS_ASSUME_NONNULL_BEGIN
 /// Cached instances of Remote Config objects.
 @property(nonatomic, strong) NSMutableDictionary<NSString *, FIRRemoteConfig *> *instances;
 
+/// Clear all the component instances from the singleton which created previously;
++ (void)clearAllComponentInstance;
+
 /// Default method for retrieving a Remote Config instance, or creating one if it doesn't exist.
 - (FIRRemoteConfig *)remoteConfigForNamespace:(NSString *)remoteConfigNamespace;
 

FirebaseRemoteConfig/Sources/FIRRemoteConfigComponent.m

@@ -40,6 +40,12 @@ + (FIRRemoteConfigComponent *)getComponentForApp:(FIRApp *)app {
   return nil;
 }
 
++ (void)clearAllComponentInstance {
+  @synchronized(_componentInstances) {
+    [_componentInstances removeAllObjects];
+  }
+}
+
 /// Default method for retrieving a Remote Config instance, or creating one if it doesn't exist.
 - (FIRRemoteConfig *)remoteConfigForNamespace:(NSString *)remoteConfigNamespace {
   if (!remoteConfigNamespace) {

FirebaseRemoteConfig/Tests/Unit/FIRRemoteConfigComponentTest.m

@@ -32,6 +32,7 @@ - (void)tearDown {
 
   // Clear out any apps that were called with `configure`.
   [FIRApp resetApps];
+  [FIRRemoteConfigComponent clearAllComponentInstance];
 }
 
 - (void)testRCInstanceCreationAndCaching {

FirebaseRemoteConfig/Tests/Unit/RCNRemoteConfigTest.m

@@ -18,6 +18,7 @@
 #import <OCMock/OCMock.h>
 #import <XCTest/XCTest.h>
 
+#import "FirebaseRemoteConfig/Sources/FIRRemoteConfigComponent.h"
 #import "FirebaseRemoteConfig/Sources/Private/FIRRemoteConfig_Private.h"
 #import "FirebaseRemoteConfig/Sources/Private/RCNConfigFetch.h"
 #import "FirebaseRemoteConfig/Sources/Public/FirebaseRemoteConfig/FIRRemoteConfig.h"
@@ -286,6 +287,7 @@ __unsafe_unretained void (^handler)(FIRRemoteConfigFetchStatus status,
 
 - (void)tearDown {
   [_DBManager removeDatabaseOnDatabaseQueueAtPath:_DBPath];
+  [FIRRemoteConfigComponent clearAllComponentInstance];
   [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:_userDefaultsSuiteName];
   [_DBManagerMock stopMocking];
   _DBManagerMock = nil;