Keypath regression

Mantle/MTLJSONAdapter.m

@@ -106,24 +106,21 @@ - (id)initWithJSONDictionary:(NSDictionary *)JSONDictionary modelClass:(Class)mo
 		NSString *JSONKeyPath = [self JSONKeyPathForPropertyKey:propertyKey];
 		if (JSONKeyPath == nil) continue;
 
-		id value = JSONDictionary;
-		NSArray *JSONKeyPathComponents = [JSONKeyPath componentsSeparatedByString:@"."];
-		for (NSString *itemJSONKeyPathComponent in JSONKeyPathComponents) {
-			if (![value isKindOfClass:NSDictionary.class]) {
-				if (error != NULL) {
-					NSDictionary *userInfo = @{
-						NSLocalizedDescriptionKey: NSLocalizedString(@"Invalid JSON dictionary", @""),
-						NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:NSLocalizedString(@"%@ could not be parsed because an invalid JSON dictionary was provided for key path \"%@\"", @""), modelClass, JSONKeyPath],
-					};
-
-					*error = [NSError errorWithDomain:MTLJSONAdapterErrorDomain code:MTLJSONAdapterErrorInvalidJSONDictionary userInfo:userInfo];
-				}
-
-				return nil;
+		id value;
+		@try {
+			value = [JSONDictionary valueForKeyPath:JSONKeyPath];
+		} @catch (NSException *ex) {
+			if (error != NULL) {
+				NSDictionary *userInfo = @{
+					NSLocalizedDescriptionKey: NSLocalizedString(@"Invalid JSON dictionary", nil),
+					NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:NSLocalizedString(@"%1$@ could not be parsed because an invalid JSON dictionary was provided for key path \"%2$@\"", nil), modelClass, JSONKeyPath],
+					MTLJSONAdapterThrownExceptionErrorKey: ex
+				};
+
+				*error = [NSError errorWithDomain:MTLJSONAdapterErrorDomain code:MTLJSONAdapterErrorInvalidJSONDictionary userInfo:userInfo];
 			}
 
-			value = [value valueForKey:itemJSONKeyPathComponent];
-			if (value == nil || value == NSNull.null) break;
+			return nil;
 		}
 
 		if (value == nil) continue;

MantleTests/MTLJSONAdapterSpec.m

@@ -88,6 +88,29 @@
 	expect(error.code).to.equal(MTLJSONAdapterErrorInvalidJSONDictionary);
 });
 
+it(@"should support key paths across arrays", ^{
+	NSDictionary *values = @{
+		@"users": @[
+			@{
+				@"name": @"foo"
+			},
+			@{
+				@"name": @"bar"
+			},
+			@{
+				@"name": @"baz"
+			}
+		]
+	};
+
+	NSError *error = nil;
+	MTLArrayTestModel *model = [MTLJSONAdapter modelOfClass:MTLArrayTestModel.class fromJSONDictionary:values error:&error];
+	expect(model).notTo.beNil();
+	expect(error).to.beNil();
+
+	expect(model.names).to.equal((@[ @"foo", @"bar", @"baz" ]));
+});
+
 it(@"should initialize without returning any error when using a JSON dictionary which Null.null as value",^{
 	NSDictionary *values = @{
 		@"username": @"foo",

MantleTests/MTLTestModel.h

@@ -41,6 +41,13 @@ extern const NSInteger MTLTestModelNameMissing;
 
 @end
 
+@interface MTLArrayTestModel : MTLModel <MTLJSONSerializing>
+
+// This property is associated with a "users.username" key in JSON.
+@property (nonatomic, copy) NSString *names;
+
+@end
+
 // Parses MTLTestModel objects from JSON instead.
 @interface MTLSubstitutingTestModel : MTLModel <MTLJSONSerializing>
 @end

MantleTests/MTLTestModel.m

@@ -120,6 +120,16 @@ - (void)mergeCountFromModel:(MTLTestModel *)model {
 
 @end
 
+@implementation MTLArrayTestModel
+
++ (NSDictionary *)JSONKeyPathsByPropertyKey {
+	return @{
+		@"names": @"users.name"
+	};
+}
+
+@end
+
 @implementation MTLSubstitutingTestModel
 
 + (NSDictionary *)JSONKeyPathsByPropertyKey {