Is it possible to test IBAction?

问题

It is kinda easy to unit test IBOutlets, but how about IBActions? I was trying to find a way how to do it, but without any luck. Is there any way to unit test connection between IBAction in a View Controller and a button in the nib file?

回答1:

For full unit testing, each outlet/action needs three tests:

1. Is the outlet hooked up to a view?
2. Is the outlet connected to the action we want?
3. Invoke the action directly, as if it had been triggered by the outlet.

I do this all the time to TDD my view controllers. You can see an example in this screencast.

It sounds like you're asking specifically about the second step. Here's an example of a unit test verifying that a touch up inside myButton will invoke the action doSomething: Here's how I express it using OCHamcrest. (sut is a test fixture for the system under test.)

- (void)testMyButtonAction {
    assertThat([sut.myButton actionsForTarget:sut
                              forControlEvent:UIControlEventTouchUpInside],
               contains(@"doSomething:", nil));
}

Alternatively, here's a version without Hamcrest:

- (void)testMyButtonAction {
    NSArray *actions = [sut.myButton actionsForTarget:sut
                              forControlEvent:UIControlEventTouchUpInside];
    XCTAssertTrue([actions containsObject:@"doSomething:"]);
}

回答2:

I did it using OCMock, like this:

MyViewController *mainView =  [[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil];
[mainView view];

id mock =  [OCMockObject partialMockForObject:mainView];

//testButtonPressed IBAction should be triggered
[[mock expect] testButtonPressed:[OCMArg any]];

//simulate button press 
[mainView.testButton sendActionsForControlEvents: UIControlEventTouchUpInside];

[mock verify];

If IBAction is not connected, the test will fail with error "expected method was not invoked".

回答3:

Here is what I use in Swift. I created a helper function that I can use in all my UIViewController unit tests:

func checkActionForOutlet(outlet: UIButton?, actionName: String, event: UIControlEvents, controller: UIViewController)->Bool{
    if let unwrappedButton = outlet {
        if let actions: [String] = unwrappedButton.actionsForTarget(controller, forControlEvent: event)! as [String] {
            return(actions.contains(actionName))
        }
    }
    return false
}

And then I just invoke it from the test like this:

func testScheduleActionIsConnected() {
    XCTAssertTrue(checkActionForOutlet(controller.btnScheduleOrder, actionName: "scheduleOrder", event: UIControlEvents.TouchUpInside, controller: controller ))
}

I am basically making sure that the button btnScheduleOrder has an IBAction associated with the name scheduleOrder for the event TouchUpInside. I need to pass the controller where the button is contained as a way to verify the target for the action as well.

You can also make it a little more sophisticated by adding some other else clause in case the unwrappedButton does not exist which means the outlet is not there. As I like to separate outlets and actions tests I don't have it included here

回答4:

Julio Bailon's answer above translated for Swift 3:

    func checkActionForButton(_ button: UIButton?, actionName: String, event: UIControlEvents = UIControlEvents.touchUpInside, target: UIViewController) -> Bool {

    if let unwrappedButton = button, let actions = unwrappedButton.actions(forTarget: target, forControlEvent: event) {

        var testAction = actionName
        if let trimmedActionName = actionName.components(separatedBy: ":").first {
            testAction = trimmedActionName
        }

        return (!actions.filter { $0.contains(testAction) }.isEmpty)
    }

    return false
}

回答5:

So, it is probably possible to instantiate a view controller from a storyboard or nib and then do a touch down on a UIButton. However, I wouldn't do this because you are then testing an Apple stock API. Rather, I would test by directly calling the method. For example if you have a method - (IBAction)foo:(id)sender in your view controller and you need to test the logic in that method, I would do something like this:

MyViewController *viewController = [[MyViewController alloc] initWithNibName:@"NibName" bundle:[NSBundle mainBundle]];

UIButton *sampleButton = [[UIButton alloc] init];
[sampleButton setTitle:@"Default Storyboard Title" forState:UIControlStateNormal];

[viewController foo:sampleButton];

// Run asserts now on the logic in foo:

回答6:

@AbbeyJackson Swift 3 version updated to Swift 4.2, thanks to @JulioBailon for the original version.

 func checkActionForButton(_ button: UIButton?, actionName: String, event: UIControl.Event = UIControl.Event.touchUpInside, target: UIViewController) -> Bool {
        if let unwrappedButton = button, let actions = unwrappedButton.actions(forTarget: target, forControlEvent: event) {
            var testAction = actionName
            if let trimmedActionName = actionName.components(separatedBy: ":").first {
                testAction = trimmedActionName
            }
            return (!actions.filter { $0.contains(testAction) }.isEmpty)
        }
        return false
    }

回答7:

Lots of good answers here already. Which works best for you depends on your testing plan.

Since this question has turned into a survey on testing methods, here's one more: if you want to test the results of manipulating your app's UI, look into the UI Automation tool in Instruments.

来源：https://stackoverflow.com/questions/18699524/is-it-possible-to-test-ibaction