Update unit tests with error handling

MantleTests/MTLJSONAdapterSpec.m

@@ -37,7 +37,7 @@
 	MTLTestModel *model = [MTLTestModel modelWithDictionary:@{
 		@"name": @"foobar",
 		@"count": @5,
-	}];
+	} error:NULL];
 
 	MTLJSONAdapter *adapter = [[MTLJSONAdapter alloc] initWithModel:model];
 	expect(adapter).notTo.beNil();

MantleTests/MTLModelNSCodingSpec.m

@@ -40,8 +40,10 @@
 			@"count": @5,
 		};
 
-		model = [[MTLTestModel alloc] initWithDictionary:values];
+		NSError *error = nil;
+		model = [[MTLTestModel alloc] initWithDictionary:values error:&error];
 		expect(model).notTo.beNil();
+		expect(error).to.beNil();
 
 		archiveAndUnarchiveModel = [^{
 			NSData *data = [NSKeyedArchiver archivedDataWithRootObject:model];

MantleTests/MTLModelSpec.m

@@ -38,8 +38,10 @@
 });
 
 it(@"should initialize to default values with a nil dictionary", ^{
-	MTLTestModel *dictionaryModel = [[MTLTestModel alloc] initWithDictionary:nil];
+	NSError *error = nil;
+	MTLTestModel *dictionaryModel = [[MTLTestModel alloc] initWithDictionary:nil error:&error];
 	expect(dictionaryModel).notTo.beNil();
+	expect(error).to.beNil();
 
 	MTLTestModel *defaultModel = [[MTLTestModel alloc] init];
 	expect(dictionaryModel).to.equal(defaultModel);
@@ -61,8 +63,10 @@
 			@"weakModel": emptyModel,
 		};
 
-		model = [[MTLTestModel alloc] initWithDictionary:values];
+		NSError *error = nil;
+		model = [[MTLTestModel alloc] initWithDictionary:values error:&error];
 		expect(model).notTo.beNil();
+		expect(error).to.beNil();
 	});
 
 	it(@"should initialize with the given values", ^{
@@ -78,7 +82,7 @@
 	it(@"should compare equal to a matching model", ^{
 		expect(model).to.equal(model);
 
-		MTLTestModel *matchingModel = [[MTLTestModel alloc] initWithDictionary:values];
+		MTLTestModel *matchingModel = [[MTLTestModel alloc] initWithDictionary:values error:NULL];
 		expect(model).to.equal(matchingModel);
 		expect(model.hash).to.equal(matchingModel.hash);
 		expect(model.dictionaryValue).to.equal(matchingModel.dictionaryValue);
@@ -98,15 +102,20 @@
 });
 
 it(@"should fail to initialize if dictionary validation fails", ^{
-	MTLTestModel *model = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"this is too long a name" }];
+	NSError *error = nil;
+	MTLTestModel *model = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"this is too long a name" } error:&error];
 	expect(model).to.beNil();
+
+	expect(error).notTo.beNil();
+	expect(error.domain).to.equal(MTLTestModelErrorDomain);
+	expect(error.code).to.equal(MTLTestModelNameTooLong);
 });
 
 it(@"should merge two models together", ^{
-	MTLTestModel *target = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"foo", @"count": @(5) }];
+	MTLTestModel *target = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"foo", @"count": @(5) } error:NULL];
 	expect(target).notTo.beNil();
 
-	MTLTestModel *source = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"bar", @"count": @(3) }];
+	MTLTestModel *source = [[MTLTestModel alloc] initWithDictionary:@{ @"name": @"bar", @"count": @(3) } error:NULL];
 	expect(source).notTo.beNil();
 
 	[target mergeValuesForKeysFromModel:source];

MantleTests/MTLTestModel.h

@@ -6,6 +6,9 @@
 //  Copyright (c) 2012 GitHub. All rights reserved.
 //
 
+extern NSString * const MTLTestModelErrorDomain;
+extern const NSInteger MTLTestModelNameTooLong;
+
 @interface MTLEmptyTestModel : MTLModel
 @end
 

MantleTests/MTLTestModel.m

@@ -8,6 +8,9 @@
 
 #import "MTLTestModel.h"
 
+NSString * const MTLTestModelErrorDomain = @"MTLTestModelErrorDomain";
+const NSInteger MTLTestModelNameTooLong = 1;
+
 static NSUInteger modelVersion = 1;
 
 @implementation MTLEmptyTestModel
@@ -18,7 +21,12 @@ @implementation MTLTestModel
 #pragma mark Properties
 
 - (BOOL)validateName:(NSString **)name error:(NSError **)error {
-	return [*name length] < 10;
+	if ([*name length] < 10) return YES;
+	if (error != NULL) {
+		*error = [NSError errorWithDomain:MTLTestModelErrorDomain code:MTLTestModelNameTooLong userInfo:nil];
+	}
+
+	return NO;
 }
 
 - (NSString *)dynamicName {