OCMock mocking UIImagePickerController

Question

I'm trying to mock UIImagePickerController to test method from ViewController (written in Swift):

var imagePicker: UIImagePickerController!

...

func choosePhoto() {
    imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    imagePicker.sourceType = .PhotoLibrary
    self.presentViewController(imagePicker, animated: true, completion: nil)
}

and the test class (written in Objective-C):

Interface:

@property (nonatomic, strong) ViewController *viewController;

Implementation:

- (void)setUp {
    [super setUp];

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UINavigationController *navigationController = [storyboard instantiateInitialViewController];
    self.viewController = (ViewController *)[navigationController visibleViewController];
    self.viewController.view;
}

....

- (void)testPicker {
    id mockPicker = [OCMockObject mockForClass:[UIImagePickerController class]];
    self.viewController.imagePicker = mockPicker;

    [[mockPicker expect] setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
    [[(id)self.viewController expect] presentViewController:mockPicker animated:YES completion:nil];

    [self.viewController choosePhoto];

    [mockPicker verify];
}

The test fails, because:

OCMockObject(UIImagePickerController): expected method was not invoked: setSourceType:0

and

failed: caught "NSInvalidArgumentException", "-[MyApp.ViewController expect]: unrecognized selector sent to instance 0x....

Can anyone help me with this?

Many thanks.

bplattenburg bplattenburg · Accepted Answer · 2015-08-25T15:59:27

So, to use the expect method from OCMock, you have to have a mock of the object that is expecting a method call. In this case, you need to have a mock for self.myViewController - the ViewController class you're using doesn't have an expect method, so its getting confused. The fact that you're casting the VC to an id is masking the issue.

OCMock mocking UIImagePickerController

1 Answers