Refactoring error creation

Author: lostintangent

ios/CodePush/CodePush.h

@@ -67,6 +67,13 @@ failCallback:(void (^)(NSError *err))failCallback;
 
 @end
 
+@interface CodePushErrorUtils : NSObject
+
++ (NSError *)errorWithMessage:(NSString *)errorMessage;
++ (BOOL)isCodePushError:(NSError *)error;
+
+@end
+
 @interface CodePushPackage : NSObject
 
 + (void)downloadPackage:(NSDictionary *)updatePackage
@@ -90,7 +97,6 @@ failCallback:(void (^)(NSError *err))failCallback;
    removePendingUpdate:(BOOL)removePendingUpdate
                  error:(NSError **)error;
 
-+ (BOOL)isCodePushError:(NSError *)err;
 + (void)rollbackPackage;
 
 // The below methods are only used during tests.

ios/CodePush/CodePush.m

@@ -221,8 +221,7 @@ + (void)ensureBinaryBundleExists
         errorMessage = [NSString stringWithFormat:@"The specified JS bundle file wasn't found within the app's binary. Is \"%@\" the correct file name?", [bundleResourceName stringByAppendingPathExtension:bundleResourceExtension]];
 #endif
 
-        RCTFatal([NSError errorWithDomain:@"CodePushError" code:-1
-                                 userInfo:@{ NSLocalizedDescriptionKey: NSLocalizedString(errorMessage, nil) }]);
+        RCTFatal([CodePushErrorUtils errorWithMessage:errorMessage]);
     }
 }
 

ios/CodePush/CodePushErrorUtils.m

@@ -0,0 +1,20 @@
+#import "CodePush.h"
+
+@implementation CodePushErrorUtils
+
+static NSString *const CodePushErrorDomain = @"CodePushError";
+static const int CodePushErrorCode = -1;
+
++ (NSError *)errorWithMessage:(NSString *)errorMessage
+{
+    return [NSError errorWithDomain:CodePushErrorDomain
+                               code:CodePushErrorCode
+                           userInfo:@{ NSLocalizedDescriptionKey: NSLocalizedString(errorMessage, nil) }];
+}
+
++ (BOOL)isCodePushError:(NSError *)err
+{
+    return err != nil && [CodePushErrorDomain isEqualToString:err.domain];
+}
+
+@end