检查UIAlertController是否在XCTest案例中呈现

Question

I'm writing unit tests for an application and want to check if a UIAlertController is presented in a specific scenario.

-(void)testBadLogin {
    // enter username and password in UITextFields
    self.viewController.usernameField.text = @"test@test.com";
    self.viewController.passwordField.text = @"incorrect_pass";
    [loginButton sendActionsForControlEvents: UIControlEventTouchUpInside];

    // this isn't right
    XCTAssertNotNil([self.viewController alertController], @"alertController should appear"); 
}

How do I check if a UIAlertController has been presented on top of the current view?

Answer 1

"XCTest is not meant to be used to test UI components." is not truly accurate. I am using XCTest for almost every UI testing and it works just fine. The correct answer shall be "Mocking".

I would use OCMock for mocking the tested view controller and "verify" that the method presentViewController... is called with the alert controller. This is a neat solution and works just fine. (You can even ignore that the alert controller is passed to this method and just test that the view controller has been passed the method presentViewController...)

Answer 2

It can also be done in this way:

Let's say we have a button which when tapped shows view controller:

- (void) didTapButton
{
    UIAlertController* c = [UIAlertController alertControllerWithTitle:@"Title" message:@"Message"
                                                        preferredStyle:UIAlertControllerStyleAlert];
    [self presentViewController:c animated:ANIMATED completion:nil];
}

Notice that ANIMATED parameter is not 'YES' or 'NO'. It is define in PrefixHeader as:

#define ANIMATED (getenv("runningTests") == NULL)

and runningTests is environment variable defined in Test target. We don't want animation when executing unit/integration tests.

The test method looks like:

- (void) testButtonWillShowAlertView
{
    UIApplication.sharedApplication.delegate.window.rootViewController = controller;
    [controller.button sendActionsForControlEvents:UIControlEventTouchUpInside];
    XCTAssertEqualObjects(controller.presentedViewController.class, UIAlertController.class);
}

Important line is

UIApplication.sharedApplication.delegate.window.rootViewController = controller;

Apparentely, rootViewController on UIWindow has to be set.

Answer 3

I have written a wrapper around UIAlertController for easier unit testing.

You can check if it is visible

XCTAssert(testableAlert.visible)

And you can also execute its actions

testableAlert.simulateAction("OK")

https://github.com/exchangegroup/TestableAlert

Answer 4

you can simply check the existence for UIAlertController By below code(objective c).

XCTAssertFalse(app.alerts.element.staticTexts[@"your alert message"].exists);

it will fail the test if alert is not presented, otherwise you can use

app.alerts.element.staticTexts[@"your alert message"].exists 

with if or XCTAssertTrue .

Answer 5

XCTest is not meant to be used to test UI components.

Use Apple's UIAutomation JavaScript Library for this:

https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/UsingtheAutomationInstrument/UsingtheAutomationInstrument.html#//apple_ref/doc/uid/TP40004652-CH20

Docs for testing Alerts: https://developer.apple.com/library/ios/documentation/ToolsLanguages/Reference/UIAAlertClassReference/index.html#//apple_ref/doc/uid/TP40009898