HelloTDDViewControllerTests.m

@implementation HelloTDDViewControllerTests {
    HelloTDDViewController *viewController;
}

- (void)setUp {
    viewController = [[HelloTDDViewController alloc] init];
}

//...

- (void)testOnButtonClickNotifiesDelegate {
    MockHelloTDDViewControllerDelegate *delegate =
            [[MockHelloTDDViewControllerDelegate alloc] init];
    viewController.delegate  = delegate;
    [viewController onButtonClick:nil];
    BOOL result = delegate.buttonWasClicked;
    STAssertTrue(result,
            @"View controller should notify delegate on button click.");
}

- (void)testOnButtonClickPassesNameToDelegate {
    MockHelloTDDViewControllerDelegate *delegate =
            [[MockHelloTDDViewControllerDelegate alloc] init];
    viewController.delegate = delegate;
    UITextField *textField = [[UITextField alloc] init];
    textField.text = @"First Last";
    viewController.nameField = textField;
    [viewController onButtonClick:nil];
    STAssertEqualObjects(delegate.lastNameSent, @"First Last",
            @"View controller should pass name to delegate.");
}

//...

@end