add heartbeat support for iid (#4323)

* add heartbeat support for iid

* format code

* fix tests

* fix formatting

Author: VinayGuthal

Example/InstanceID/Tests/FIRInstanceIDTokenOperationsTest.m

@@ -33,6 +33,7 @@
 #import "Firebase/InstanceID/NSError+FIRInstanceID.h"
 
 #import <FirebaseCore/FIRAppInternal.h>
+#import <GoogleUtilities/GULHeartbeatDateStorage.h>
 
 static NSString *kDeviceID = @"fakeDeviceID";
 static NSString *kSecretToken = @"fakeSecretToken";
@@ -83,6 +84,11 @@ - (void)setUp {
   _keyPair =
       [[FIRInstanceIDKeychain sharedInstance] generateKeyPairWithPrivateTag:kPrivateKeyPairTag
                                                                   publicTag:kPublicKeyPairTag];
+
+  NSString *const kHeartbeatStorageFile = @"HEARTBEAT_INFO_STORAGE";
+  GULHeartbeatDateStorage *dataStorage =
+      [[GULHeartbeatDateStorage alloc] initWithFileName:kHeartbeatStorageFile];
+  [[NSFileManager defaultManager] removeItemAtURL:[dataStorage fileURL] error:nil];
 }
 
 - (void)tearDown {
@@ -319,7 +325,7 @@ - (void)testHTTPAuthHeaderGenerationFromCheckin {
   XCTAssertEqualObjects(generatedHeader, expectedHeader);
 }
 
-- (void)testTokenFetchOperationFirebaseUserAgentHeader {
+- (void)testTokenFetchOperationFirebaseUserAgentAndHeartbeatHeader {
   XCTestExpectation *completionExpectation =
       [self expectationWithDescription:@"completionExpectation"];
 
@@ -336,6 +342,8 @@ - (void)testTokenFetchOperationFirebaseUserAgentHeader {
       ^(NSURLRequest *request, FIRInstanceIDURLRequestTestResponseBlock response) {
         NSString *userAgentValue = request.allHTTPHeaderFields[kFIRInstanceIDFirebaseUserAgentKey];
         XCTAssertEqualObjects(userAgentValue, [FIRApp firebaseUserAgent]);
+        NSString *heartBeatCode = request.allHTTPHeaderFields[kFIRInstanceIDFirebaseHeartbeatKey];
+        XCTAssertEqualObjects(heartBeatCode, @"3");
 
         // Return a response with Error=RST
         NSData *responseBody = [self dataForFetchRequest:request returnValidToken:NO];

Firebase/InstanceID/FIRInstanceIDTokenFetchOperation.h

@@ -20,6 +20,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 FOUNDATION_EXPORT NSString *const kFIRInstanceIDFirebaseUserAgentKey;
 
+FOUNDATION_EXPORT NSString *const kFIRInstanceIDFirebaseHeartbeatKey;
+
 @interface FIRInstanceIDTokenFetchOperation : FIRInstanceIDTokenOperation
 
 - (instancetype)initWithAuthorizedEntity:(NSString *)authorizedEntity

Firebase/InstanceID/FIRInstanceIDTokenFetchOperation.m

@@ -26,13 +26,16 @@
 #import "NSError+FIRInstanceID.h"
 
 #import <FirebaseCore/FIRAppInternal.h>
+#import <FirebaseCore/FIRHeartbeatInfo.h>
 
 // We can have a static int since this error should theoretically only
 // happen once (for the first time). If it repeats there is something
 // else that is wrong.
 static int phoneRegistrationErrorRetryCount = 0;
 static const int kMaxPhoneRegistrationErrorRetryCount = 10;
 NSString *const kFIRInstanceIDFirebaseUserAgentKey = @"X-firebase-client";
+NSString *const kFIRInstanceIDFirebaseHeartbeatKey = @"X-firebase-client-log-type";
+NSString *const kFIRInstanceIDHeartbeatTag = @"fire-iid";
 
 @implementation FIRInstanceIDTokenFetchOperation
 
@@ -60,6 +63,8 @@ - (void)performTokenOperation {
   [request setValue:checkinVersionInfo forHTTPHeaderField:@"info"];
   [request setValue:[FIRApp firebaseUserAgent]
       forHTTPHeaderField:kFIRInstanceIDFirebaseUserAgentKey];
+  [request setValue:@([FIRHeartbeatInfo heartbeatCodeForTag:kFIRInstanceIDHeartbeatTag]).stringValue
+      forHTTPHeaderField:kFIRInstanceIDFirebaseHeartbeatKey];
 
   // Build form-encoded body
   NSString *deviceAuthID = self.checkinPreferences.deviceID;