Updated GIDTokenClaimsInternalOptionsTest to test correct expected error.

Author: AkshatG6

GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.h

@@ -22,10 +22,13 @@ NS_ASSUME_NONNULL_BEGIN
 @interface GIDFakeJSONSerializerImpl : NSObject <GIDJSONSerializer>
 
 /**
- * The error to be returned by `stringWithJSONObject:error:`.
- * If `nil`, the method will attempt to perform a real serialization.
+ * A flag to control whether the serialization method should fail.
+ *
+ * If set to `YES`, `stringWithJSONObject:error:` will return `nil` and
+ * populate the error parameter with a serialization failure error.
+ * If `NO` (the default), it will attempt a real serialization.
  */
-@property(nonatomic, nullable) NSError *errorToReturn;
+@property(nonatomic, assign) BOOL shouldFailJSONSerialization;
 
 /** The dictionary passed to the serialization method. */
 @property(nonatomic, readonly, nullable) NSDictionary<NSString *, id> *capturedJSONObject;

GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.m

@@ -16,17 +16,28 @@
 
 #import "GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.h"
 
+#import "GoogleSignIn/Sources/GIDJSONSerializer/Implementation/GIDJSONSerializerImpl.h"
+#import "GoogleSignIn/Sources/Public/GoogleSignIn/GIDSignIn.h"
+
 @implementation GIDFakeJSONSerializerImpl
 
 - (nullable NSString *)stringWithJSONObject:(NSDictionary<NSString *, id> *)jsonObject
                                       error:(NSError *_Nullable *_Nullable)error {
   _capturedJSONObject = [jsonObject copy];
-  if (self.errorToReturn) {
+
+  // Check the boolean flag to see if we should simulate a failure.
+  if (self.shouldFailJSONSerialization) {
     if (error) {
-      *error = self.errorToReturn;
+      *error = [NSError errorWithDomain:kGIDSignInErrorDomain
+                                   code:kGIDSignInErrorCodeJSONSerializationFailure
+                               userInfo:@{
+                            NSLocalizedDescriptionKey:kGIDJSONSerializationErrorDescription,
+                               }];
     }
     return nil;
   }
+
+  // If not failing, fall back to the real serialization path.
   NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonObject
                                                  options:0
                                                    error:error];

GoogleSignIn/Tests/Unit/GIDTokenClaimsInternalOptionsTest.m

@@ -15,6 +15,7 @@
 #import <XCTest/XCTest.h>
 
 #import "GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.h"
+#import "GoogleSignIn/Sources/GIDJSONSerializer/Implementation/GIDJSONSerializerImpl.h"
 #import "GoogleSignIn/Sources/GIDTokenClaimsInternalOptions.h"
 #import "GoogleSignIn/Sources/Public/GoogleSignIn/GIDSignIn.h"
 #import "GoogleSignIn/Sources/Public/GoogleSignIn/GIDTokenClaim.h"
@@ -23,8 +24,10 @@
 static NSString *const kNonEssentialAuthTimeExpectedJSON = @"{\"id_token\":{\"auth_time\":{\"essential\":false}}}";
 
 @interface GIDTokenClaimsInternalOptionsTest : XCTestCase
+
 @property(nonatomic) GIDFakeJSONSerializerImpl *jsonSerializerFake;
 @property(nonatomic) GIDTokenClaimsInternalOptions *tokenClaimsInternalOptions;
+
 @end
 
 @implementation GIDTokenClaimsInternalOptionsTest
@@ -89,15 +92,22 @@ - (void)testValidatedJSONStringForClaims_WithConflictingClaims_ReturnsNilAndPopu
 
 - (void)testValidatedJSONStringForClaims_WhenSerializationFails_ReturnsNilAndError {
   NSSet *claims = [NSSet setWithObject:[GIDTokenClaim authTimeClaim]];
-  NSError *expectedJSONError = [NSError errorWithDomain:@"com.fake.json" code:-999 userInfo:nil];
-  _jsonSerializerFake.errorToReturn = expectedJSONError;
+  NSError *expectedJSONError = [NSError errorWithDomain:kGIDSignInErrorDomain
+                                                   code:kGIDSignInErrorCodeJSONSerializationFailure
+                                               userInfo:@{
+                                                 NSLocalizedDescriptionKey: kGIDJSONSerializationErrorDescription,
+                                               }];
+  _jsonSerializerFake.shouldFailJSONSerialization = YES;
   NSError *actualError;
-  NSString *result =
-  [_tokenClaimsInternalOptions validatedJSONStringForClaims:claims error:&actualError];
+  NSString *result = [_tokenClaimsInternalOptions validatedJSONStringForClaims:claims
+                                                                         error:&actualError];
 
   XCTAssertNil(result, @"The result should be nil when JSON serialization fails.");
-  XCTAssertEqualObjects(actualError, expectedJSONError,
-                        @"The error from serialization should be passed back to the caller.");
+  XCTAssertEqualObjects(
+      actualError,
+      expectedJSONError,
+      @"The error from serialization should be passed back to the caller."
+  );
 }
 
 @end