Architecting your apps for UI Testing

Talk given at NSSpain 2016

Transcript

1. Architecting your apps for UI Testing Alberto Gragera Co-Founder and Technical Director @gragera_ alberto@karumi.com
2. This is NOT about acceptance tests
3. Why invest in UI Testing?
4. Test from the user’s point of view
5. Reproduce any imaginable scenario
6. Architecture
7. GOOD ARCHITECTURE Readability Testability Embrace change Robustness
8. BAD ARCHITECTURE Fear of change Lots of WTFs Hacks Mystic knowledge
9. What main features should your architecture have to enable you to write UI tests effectively?
10. Each layer must have a crystal clear purpose and responsibilities
11. Be able to replace the dependencies to inject test doubles
12. Disclaimer: Viper-ish
13. UI PRESENTER USE CASE NAVIGATOR REPOSITORY DATA SOURCE … N … COMPOSITION ROOT COMPOSITION ROOT A … N …
14. UI PRESENTER USE CASE NAVIGATOR REPOSITORY DATA SOURCE … N COMPOSITION ROOT COMPOSITION ROOT A … N … …
15. UI Abstraction over UIViewController Passive Views
16. Use Cases Gateway to the “data” world Expose what your domain layer can do
17. Navigator Navigates from one screen to another Knows about the state of the screen at any given time Handle the presentation of this new screen
18. CompositionRoot Knows how to instantiate every collaborator of the app Knows about the particulars of a collaborator
19. Presenter Tell the UI what to do Tell Navigators where the user wants to go Execute Use Cases KEY point for dependency injection
20. How does this look like in a real app?
21. FoursquareTop
22. App launch
23. Screen AppDelegate private func installRootNavigator() { let builder = AppCompositionRoot.Builder() appCompositionRoot = builder.with( venueCompositionRoot: VenueCompositionRoot() ).build() navigator = RootNavigator( appCompositionRoot: appCompositionRoot ) navigator.installRootViewController(window!) window?.makeKeyAndVisible() } 1 2 3
24. DEPENDENCIES RootNavigator func installRootViewController(window: UIWindow) { let vc = appCompositionRoot.getInitialViewController() currentNavigationController = vc window.rootViewController = vc }
25. DEPENDENCIES AppCompositionRoot class AppCompositionRoot { let venue: VenueCompositionRoot func getInitialViewController() -> UINavigationController { let vc = venue.getBestVenuesAroundViewController() return UINavigationController(rootViewController: vc) } }
26. DEPENDENCIES VenueCompositionRoot func getBestVenuesAroundViewController() -> UIViewController { let vc = BestVenuesAroundYouViewController() vc.venuesAroundYouPresenter = BestVenuesAroundYouPresenter( ui: vc, getBestPlacesAroundYouUseCase: getPlacesAroundYouUseCase(), getUserLocationUseCase: getUserLocationUseCase(), navigator: getVenueListNavigator() ) return vc }
27. Going to a venue detail
28. TAP
29. presenter.venueSelected(venue) UI navigator.goTo(venue) PRESENTER compositionRoot.getVC(venue) pushViewController() NAVIGATOR
30. Screen BestVenuesAroundYouViewController func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) { guard let venue = ds.venue(atIndexPath: indexPath) else { return } venuesAroundYouPresenter.venueSelected(venue) }
31. Screen BestVenuesAroundYouPresenter func venueSelected(venue: VenueViewModel) { navigator.goTo(venueDetail: venue) }
32. DEPENDENCIES VenueListNavigator func goTo(venueDetail venue: VenueViewModel) { let vc = appCompositionRoot.venue.getVenueDetailViewController( forVenue: venue ) currentNavigationController?.pushViewController( vc, animated: true ) }
33. Testing this
34. STRATEGY
35. UI PRESENTER USE CASE NAVIGATOR REPOSITORY DATA SOURCE … N … COMPOSITION ROOT COMPOSITION ROOT A … N …
36. TEST main.swift let appDelegateClass = Environment().isInTestingRun() ? NSStringFromClass(AppDelegateForTests) : NSStringFromClass(AppDelegate) UIApplicationMain( Process.argc, Process.unsafeArgv, nil, appDelegateClass )
37. TEST AppDelegateForTests func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject : AnyObject]?) -> Bool { window = UIWindow(frame: UIScreen.mainScreen().bounds )! window.backgroundColor = .whiteColor() window.makeKeyAndVisible() window.rootViewController = UINavigationController() return true }
38. TEST BaseUITest func openViewController() { let appCompositionRoot = getTestingAppCompositionRoot( baseAppCompositionRoot ) rootNavigator = RootNavigator( appCompositionRoot: appCompositionRoot ) presentViewController( keyWindow, navigator: rootNavigator, appCompositionRoot: appCompositionRoot ) } 1 2 3
39. Test Cases
40. TEST BestVenuesAroundYouViewControllerTests class BestVenuesAroundYouViewControllerTests: BaseUITestCase { private var stubVenueListNavigator: StubVenueListNavigator! private var getUserLocation: StubGetUserLocationUseCase! private var getBestPlacesAroundYou: StubGetBestPlacesAroundYouUseCase! override func setUp() { super.setUp() getUserLocation = StubGetUserLocationUseCase() getBestPlacesAroundYou = StubGetBestPlacesAroundYouUseCase() stubVenueListNavigator = StubVenueListNavigator() }
41. TEST BestVenuesAroundYouViewControllerTests override func getTestingAppCompositionRoot(compositionRoot: AppCompositionRoot) -> AppCompositionRoot { return AppCompositionRoot.Builder() .with(venueCompositionRoot: getVenueCompositionRoot()) .build() } private func getVenueCompositionRoot() -> VenueCompositionRoot { let venueCompositionRoot = TestingVenueCompositionRoot() venueCompositionRoot.stubGetUserLocation = getUserLocation venueCompositionRoot.stubGetBestPlacesAroundYou = getBestPlacesAroundYou venueCompositionRoot.stubVenueListNavigator = stubVenueListNavigator return venueCompositionRoot }
42. TEST func getGetUserLocationUseCase() -> GetUserLocationUseCase { return GetUserLocation( gps: getGPS(), repository: getVenueDataSource() ) } func getGetUserLocationUseCase() -> GetUserLocationUseCase { return stubGetUserLocationUseCase } VenueCompositionRoot TestingVenueCompositionRoot
43. TEST BestVenuesAroundYouViewControllerTests func testLoadingIndicatorIsVisibleWhenLoadingVenues() { givenWeAreFetchingUsersLocation() openViewController() waitForViewWithLocalizedAccessibilityLabel(.Loading) } override func presentViewController(window: UIWindow, navigator: RootNavigator, appCompositionRoot: AppCompositionRoot) { presentViewController( appCompositionRoot.venue.getBestVenuesAroundViewController() ) }
44. TEST BestVenuesAroundYouViewControllerTests func testOpenSettingsIfTheGPSAccessIsDeniedAndTheUserOpensSettings() { givenThereWillBeAnErrorFetchingUserLocation(error: .AccessDenied) openViewController() tapGoToSettings() expect( stubVenueListNavigator.didNavigateToSettings ).toEventually( equal(true) ) } GIVEN WHEN THEN
45. TEST BestVenuesAroundYouViewControllerTests func testRetryShowsVenuesAfterThereIsAnErrorFetchingUsersLocation() { getUserLocationUseCase.givenThereWillBeAnErrorFetchingUsersLocation() openViewController() expectCanNotFetchLocationError(toBeVisible: true) getBestPlacesAroundYouUseCase.givenThereWillBeVenues() tapRetry() expectVenueList( getBestPlacesAroundYouUseCase.venueList ) expectCanNotFetchLocationError(toBeVisible: false) }
46. Testing the real navigation
47. TEST BestVenuesAroundYouViewControllerNavigationTests override func presentViewController(window: UIWindow, navigator: RootNavigator, appCompositionRoot: AppCompositionRoot) { navigator.installRootViewController(window) } override func getTestingAppCompositionRoot(compositionRoot: AppCompositionRoot) -> AppCompositionRoot { return AppCompositionRoot.Builder(compositionRoot: compositionRoot) .with(venueCompositionRoot: getVenueCompositionRoot()) .build() } private func getVenueCompositionRoot() -> VenueCompositionRoot { let venueCompositionRoot = TestingVenueCompositionRoot() venueCompositionRoot.stubGetUserLocationUseCase = getUserLocationUseCase venueCompositionRoot.stubGetBestPlacesAroundYouUseCase = getBestPlacesAroundYouUseCase venueCompositionRoot.stubGetVenueDetailsUseCase = getVenueDetailsUseCase return venueCompositionRoot } private func getVenueCompositionRoot() -> VenueCompositionRoot { let venueCompositionRoot = TestingVenueCompositionRoot() venueCompositionRoot.stubGetUserLocation = getUserLocation venueCompositionRoot.stubGetBestPlacesAroundYou = getBestPlacesAroundYou venueCompositionRoot.stubVenueListNavigator = stubVenueListNavigator return venueCompositionRoot } BestVenuesAroundYouViewControllerTests
48. TEST BestVenuesAroundYouViewControllerNavigationTests func testNavigatesToVenueDetailWhenUserTapsOnVenue() { getVenuesUseCase.givenThereWillBeVenues() let topVenue = getVenuesUseCase.getTopVenue() getVenueDetailsUseCase.venue = topVenue openViewController() tapTopVenue() expectTitle(ofVenue: topVenue, toBeVisible: true) } GIVEN WHEN THEN
49. Why is all this possible?
50. Thanks!
51. Questions?