adding unit test for auto init enable function (firebase#710)

Author: charlotteliang

Example/Messaging/App/iOS/Messaging-Info.plist

@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>FirebaseMessagingAutoInitEnabled</key>
+	<false/>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>en</string>
 	<key>CFBundleDisplayName</key>

Example/Messaging/Tests/FIRMessagingTest.m

@@ -20,6 +20,7 @@
 
 #import "FIRMessaging.h"
 #import "FIRMessagingInstanceIDProxy.h"
+#import "FIRMessaging_Private.h"
 
 extern NSString *const kFIRMessagingFCMTokenFetchAPNSOption;
 
@@ -28,6 +29,7 @@ @interface FIRMessaging ()
 @property(nonatomic, readwrite, strong) NSString *defaultFcmToken;
 @property(nonatomic, readwrite, strong) NSData *apnsTokenData;
 @property(nonatomic, readwrite, strong) FIRMessagingInstanceIDProxy *instanceIDProxy;
+@property(nonatomic, readwrite, strong) NSUserDefaults *messagingUserDefaults;
 
 - (instancetype)initPrivately;
 // Direct Channel Methods
@@ -52,6 +54,9 @@ - (void)setUp {
   _mockMessaging = OCMPartialMock(self.messaging);
   _mockInstanceIDProxy = OCMPartialMock(self.messaging.instanceIDProxy);
   self.messaging.instanceIDProxy = _mockInstanceIDProxy;
+  [self.messaging.messagingUserDefaults removePersistentDomainForName:kFIRMessagingSuiteName];
+  self.messaging.messagingUserDefaults =
+      [[NSUserDefaults alloc] initWithSuiteName:kFIRMessagingSuiteName];
 }
 
 - (void)tearDown {
@@ -60,6 +65,15 @@ - (void)tearDown {
   [super tearDown];
 }
 
+- (void)testAutoInitEnableFlag {
+  // Should read from Info.plist
+  XCTAssertFalse(_messaging.isAutoInitEnabled);
+
+  // Now set the flag should overwrite Info.plist value.
+  _messaging.autoInitEnabled = YES;
+  XCTAssertTrue(_messaging.isAutoInitEnabled);
+}
+
 #pragma mark - Direct Channel Establishment Testing
 
 // Should connect with valid token and application in foreground

Example/Messaging/Tests/Info.plist

@@ -20,5 +20,7 @@
 	<string>????</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
+        <key>FirebaseMessagingAutoInitEnabled</key>
+        <false/>
 </dict>
 </plist>