Sample iOS Unit Tests: Working with a ViewController composed of a UIButton

Sample iOS Unit Tests: Working with a ViewController composed of a UIButton

import XCTest
@testable import projectname

class ExampleTests: XCTestCase {

    var viewControllerUnderTest: MyViewController!

    override func setUp() {
        super.setUp()

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        self.viewControllerUnderTest = storyboard.instantiateViewControllerWithIdentifier("MyViewController") as! MyViewController
        
        self.viewControllerUnderTest.loadView()
        self.viewControllerUnderTest.viewDidLoad()
    }

    func testViewControllerUnderTestIsComposedOfButton() {
        
        XCTAssertNotNil(self.viewControllerUnderTest.button, "Does not have a button")
    }
    
    func testButtonInvokesActionMethodWhenTapped() {
        
        let actionMethod = self.viewControllerUnderTest.button.actionsForTarget(self.viewControllerUnderTest, forControlEvent: UIControlEvents.TouchUpInside)
        let actualMethodName = actionMethod?.first
        let expectedMethodName = "handleTap:"
        
        XCTAssertEqual(actualMethodName, expectedMethodName, "Actual: \(actualMethodName) not equal to expected: \(expectedMethodName)")
    }
    
    func testViewControllerUnderTestIsComposedOfLabel() {
        
        XCTAssertNotNil(self.viewControllerUnderTest.label, "Does not have label")
    }
    
    func testLabelAfterButtonTap() {
        
        let button: UIButton = UIButton()
        viewControllerUnderTest.handleTap(button)
        
        // alterantively tap button with
        // viewControllerUnderTest.button.sendActionsForControlEvents(UIControlEvents.TouchUpInside)
        
        let expectedLabelText = "Hello testing"
        let actualLabelText = viewControllerUnderTest.label.text
        
        XCTAssertEqual(expectedLabelText, actualLabelText, "Label text of: \(expectedLabelText) not equal to text: \(actualLabelText)")
    }
}