Updated GIDFakeJSONSerializerImpl to accept a seeded error instead of a BOOL.

Author: AkshatG6

GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.h

@@ -22,13 +22,12 @@ NS_ASSUME_NONNULL_BEGIN
 @interface GIDFakeJSONSerializerImpl : NSObject <GIDJSONSerializer>
 
 /**
- * A flag to control whether the serialization method should fail.
+ * An error to be returned by `stringWithJSONObject:error:`.
  *
- * 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.
+ * If this property is set, `stringWithJSONObject:error:` will return `nil` and
+ * populate the error parameter with this error.
  */
-@property(nonatomic, assign) BOOL shouldFailJSONSerialization;
+@property(nonatomic, nullable) NSError *serializationError;
 
 /** The dictionary passed to the serialization method. */
 @property(nonatomic, readonly, nullable) NSDictionary<NSString *, id> *capturedJSONObject;

GoogleSignIn/Sources/GIDJSONSerializer/Fake/GIDFakeJSONSerializerImpl.m

@@ -25,14 +25,10 @@ - (nullable NSString *)stringWithJSONObject:(NSDictionary<NSString *, id> *)json
                                       error:(NSError *_Nullable *_Nullable)error {
   _capturedJSONObject = [jsonObject copy];
 
-  // Check the boolean flag to see if we should simulate a failure.
-  if (self.shouldFailJSONSerialization) {
+  // Check if a serialization error should be simulated.
+  if (self.serializationError) {
     if (error) {
-      *error = [NSError errorWithDomain:kGIDSignInErrorDomain
-                                   code:kGIDSignInErrorCodeJSONSerializationFailure
-                               userInfo:@{
-                            NSLocalizedDescriptionKey:kGIDJSONSerializationErrorDescription,
-                               }];
+      *error = self.serializationError;
     }
     return nil;
   }

GoogleSignIn/Tests/Unit/GIDTokenClaimsInternalOptionsTest.m

@@ -97,7 +97,7 @@ - (void)testValidatedJSONStringForClaims_WhenSerializationFails_ReturnsNilAndErr
                                                userInfo:@{
                                                  NSLocalizedDescriptionKey: kGIDJSONSerializationErrorDescription,
                                                }];
-  _jsonSerializerFake.shouldFailJSONSerialization = YES;
+  _jsonSerializerFake.serializationError = expectedJSONError;
   NSError *actualError;
   NSString *result = [_tokenClaimsInternalOptions validatedJSONStringForClaims:claims
                                                                          error:&actualError];