Thoughts on how the API for class mocking in ObjectiveC should look

Class method mocking?

// I'd think that if NSString doesn't get sent stringWithFormat here before the end of this test, it should raise an error? It's mocking after all, not stubbing.
- (void)testClassMethodMocking {
  [NSString mock:@selector(stringWithFormat:) andReturn:@"someString"];

  NSString *string = [NSString stringWithFormat@"abc123"];

  GHAssertEqual(string, @"someString", "NSString hasn't been mocked")
}

// This guy wouldn't raise.
- (void)testClassMethodStubbing {
  [NSString stub:@selector(stringWithFormat:) andReturn:@"someString"];

  NSString *string = [NSString stringWithFormat@"abc123"];

  GHAssertEqual(string, @"someString", "NSString hasn't been mocked")
}

// Not too sure how to pass argument assertions though
- (void)testClassMethodMockingWithArguments {
  NSDate *date = [NSDate date];
  [NSString mock:@selector(stringWithFormat) withArgs:date, nil andReturn:@"11-06-2011"];

  NSString *string = [NSString stringWithFormat:@"%@", date];
  GHAssertEqual(string, @"11-06-2011", "NSString hasn't been mocked");
}