gistfile1.m

@interface TestClass1 : NSObject
+ (NSString *)getSomeString;
- (NSString *)doSomething;
- (NSString *)doSomethingElse;
@end

@interface TestClass1 (TestClass1Catgegory)
+ (NSString *)ext_getSomeString:(NSString *)input;
@end

@implementation TestClass1
+ (NSString *)getSomeString
{
    return @"getSomeStringResult";
}
- (NSString *)doSomething
{
    return [TestClass1 getSomeString];
}
- (NSString *)doSomethingElse
{
    return [TestClass1 ext_getSomeString:@"ext"];
}
@end

@implementation TestClass1 (TestClass1Catgegory)
+ (NSString *)ext_getSomeString:(NSString *)input
{
    return [input stringByAppendingString:@"-got"];
}
@end

SPEC_BEGIN(ShouldReceiveSpec)
describe(@"Attempt to repor 'MagicalRecord MR_createInContext: returns nil'", ^{
    it(@"should not return nil when using shouldReceive on a class method", ^{
        TestClass1 *object = [TestClass1 new];
        [[[TestClass1 class] should] receive:@selector(getSomeString)];
        NSString *result = [object doSomething];
        [[result should] equal:@"getSomeStringResult"];
    });
    it(@"should not return nil when using shouldReceive on a class method defined in a category", ^{
        TestClass1 *object = [TestClass1 new];
        [[[TestClass1 class] should] receive:@selector(ext_getSomeString:)];
        NSString *result = [object doSomethingElse];
        [[result should] equal:@"ext-got"];
    });
});
SPEC_END