TDD in iOS

German presentation about TDD in iOS

Transcript

1. TDD und iOS Dominik Hauser, @dasdom
2. The quality and performance achieved could not have been done without the use of unit testing. — Bill Bumgarner (bbum), über Core Data 1.0
3. Vorteile
4. Vorteile1 · Refaktorierbarkeit · Schnelles Feedback · Gedankenstütze · Doppelte Buchführung · Regressionsschutz 1 Von (subjektiv) wichtig nach unwichtig
5. Planning/Feedback Loops Release Plan Code Iteration Plan Acceptance Test Stand Up Meeting Pair Negotiation Unit Test Pair Programming Months Weeks Days One day Hours Minutes Seconds DonWells (CC BY-SA 3.0)
6. Wie? Red Green Refactor
7. Warum so wenig Tests?
8. "Was soll denn da kaputt gehen?"
9. if index-1 < userNames.count { nameLabel.text = userNames[index] } else { nameLabel.text = "Unknown" }
10. if index-1 < userNames.count { nameLabel.text = userNames[index] } else { nameLabel.text = "Unknown" }
11. class TableViewCell: UITableViewCell { let label = UILabel() override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) { super.init(style: style, reuseIdentifier: reuseIdentifier) addSubview(label) } }
12. class TableViewCell: UITableViewCell { let label = UILabel() override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) { super.init(style: style, reuseIdentifier: reuseIdentifier) addSubview(label) } }
13. "Was soll denn da kaputt gehen?" 1. That can’t happen. 2. That doesn’t happen on my machine. 3. That shouldn’t happen. 4. Why does that happen? 5. Oh, I see. 6. How did that ever work?2 2 Mike W. Cremer
14. "Machen wir nach dem Release."
15. RELEASE 1.0 TESTS RELEASE 1.1 Login Login Tests User User Tests Logout Logout Tests Password reset Password Tests Blocking of users Blocking tests ... ...
16. RELEASE 1.0 RELEASE 1.1 TESTS Login Login Tests User User Tests Logout Logout Tests Password reset Password Tests Blocking of users Blocking tests ... ...
17. RELEASE 1.0 RELEASE 1.1 RELEASE 1.1.1 Login User Logout Password reset Blocking of users ... ...
18. Nach den Release ist vor den Release
19. "UI kann man nicht testen."
20. func test_viewHasLabel() { sut.loadViewIfNeeded() XCTAssertTrue(sut.label.isDescendant(of: sut.view)) }
21. func test_loadingView_registersCell() { // when sut.loadViewIfNeeded() // then let cell = sut.tableView.dequeueReusableCell( withIdentifier: "Cell", for: IndexPath(row: 0, section: 0)) XCTAssertNotNil(cell) XCTAssertTrue(cell is Cell) }
22. func test_showNext_pushesViewController() { // given let navControllerMock = NavigationControllerMock( rootViewController: sut) let user = User(name: "Foobar") // when sut.showNext(with: user) // then let detailController = navControllerMock.lastPushedVC as! DetailViewController XCTAssertEqual(detailController.user, user) }
23. "UI kann man nicht testen." Kann man
24. Tips & Tricks
25. Dependency Injection (Inversion of Control)
26. Zum Beispiel: Constructor Injection let defaultsStub = DefaultsStub(boolToReturn: false) let user = User(defaults: defaultsStub)
27. Ausserdem · Constructor Injection · Setter Injection · Interface Injection
28. Abstraktion
29. Abstraktion Beispiel: Alerts protocol Alerter { func presentOKAlert(on: UIViewController, title: String, message: String, okAction: ()->Void) }
30. View laden func test_foo() { // given ... // when view loads sut.loadViewIfNeeded() // then ... }
31. viewWill/DidAppear func test_foo() { // given ... // when view appears sut.beginAppearanceTransition(true, animated: false) sut.endAppearanceTransition() // then ... }
32. Modal presentation func test_presentationOfViewController() { // given let window = UIWindow(frame: CGRect(x: 0, y: 0, width: 300, height: 300)) window.rootViewController = sut window.makeKeyAndVisible() // when sut.showNext() // then XCTAssertTrue(sut.presentedViewController is DetailViewController) }
33. Bestehender Code Wie anfangen?
34. Bug ➜ Test
35. Neues Feature ➜ Test
36. pragprog.com/book/jrlegios/ ios-unit-testing-by-example
37. Promolink http://leanpub.com/ tdd_ios_gimme_the_cod e/c/macdev
39. Promolink http://leanpub.com/ tdd_ios_gimme_the_cod e/c/macdev
40. Ende
41. Ende!