HomeScreenViewControllerSpec.swift

import XCTest
import Nimble
import Fleet

@testable import FleetExamples

class HomeScreenViewControllerSpec: XCTestCase {
    var subject: HomeScreenViewController!
    var mockAlertPageViewController: AlertPageViewController!
    var navigationController: UINavigationController!

    override func setUp() {
        super.setUp()

        // We want to test the behavior of the home page, which comes from a storyboard. First,
        // get the storyboard.
        let storyboard = UIStoryboard(name: "Main", bundle: nil)

        // From the home page we can go to many different pages, all connected by segues. Fleet
        // make it trivial to test those segues. For example, here we use Fleet to mock out
        // the view controller produced anytime UIKit wants to instantiate a view controller with
        // the storyboard identifier "AlertPageViewController".
        mockAlertPageViewController = try! storyboard.mockIdentifier("AlertPageViewController", usingMockFor: AlertPageViewController.self)
        subject = storyboard.instantiateViewController(withIdentifier: "HomeScreenViewController") as! HomeScreenViewController

        // This is how you kick off the lifecycle of your view controller under test.
        // For more on why Fleet recommends you test view controllers in a window,
        // read the 'Why should I make sure all UIViewController unit tests happen in a
        // UIWindow?' FAQ section.

        // This version sets up the 'subject' in a UINavigationController.
        // You could also use `Fleet.setAsAppWindowRoot(_:)` to set the 'subject'
        // directly as the root of a window.
        navigationController = Fleet.setInAppWindowRootNavigation(subject)
    }

    func test_afterHomeScreenLoads_updatesLoadingStatusLabel() {
        expect(self.subject.loadingStatusLabel?.text).to(equal("Finished loading!"))
    }

    func test_tappingTheGoToAlertPageButton_presentsAlertPage() {
        // When you want to test what a button on the screen does, just "tap" it.
        // This is where the real power of Fleet comes in -- tapping this button
        // fires a segue to present a new page...
        try! subject.goToAlertPageButton?.tap()

        // ... and now we want to see the result. Recall above how we mocked out the "AlertPageViewController"
        // identifier. It's time to use that mock.

        // Verifying that your segue successfully presented the right controller is done in one line.
        expect(Fleet.getApplicationScreen()?.topmostViewController).toEventually(beIdenticalTo(mockAlertPageViewController))

        // The following assertion is functionally equivalent to the above.
        expect(self.navigationController.topViewController).toEventually(beIdenticalTo(mockAlertPageViewController))
    }
}