TDD Workshop - UIKonf 2016

Transcript

1. Test Driven Development
2. Why do we need tests?
3. Preserving behaviors
4. We're just humans
5. Failsafe
6. Test Driven Development
7. Tests drive the way you code
8. Always write test first
9. Tests influence architecture of your app
10. Tests tell you whether your design became too complex
11. Have to simulate behavior of your dependency dependency dependency?
12. Need to fake seven objects?
13. Need to call five functions to simulate a behavior?
14. Hard to specify clear requirements?
15. Overcomplicated design
16. Thinked-through design
17. First consumer of your API
18. Programs must be written for people to read, and only incidentally for machines to execute. — Harold Abelson
19. There is no such thing as untestable behavior Only untestable code
20. What is testable code?
21. Good Architecture == Testable code
22. What is good architecture?
23. Cohesion
24. Coupling
25. Good design A simple definition
26. High cohesion and low coupling
27. Easily composable and context independent
28. Good architecture - base rules » Single responsibility » Few dependencies » Depend on interfaces, not classes (yay POP!)
30. !!!
31. http://www.martinfowler.com/ bliki/ DesignStaminaHypothesis.html
32. SOLID
33. SOLID Homework » Goruco 2009 - SOLID Object-Oriented Design - Sandi Metz » MCE^3 - Software Paradigms & Patterns — Did We Get It All Wrong? - Jon Reid » MCE^3 - Jorge Ortiz » Clean Architecture - Uncle Bob
34. What is BDD
35. Behavior Driven Development Test Driven Development
36. What's the difference?
37. BDD aims to improve certain aspect of TDD
38. BDD tries to help you know what to test
39. When writing tests don’t think ‘tests’
40. Think about ‘behaviors’
41. Think about examples how your object should behave
42. An objects behavior is defined by methods it declares in its interface
43. You should not be testing internal implementation of your object Only its interface
44. Work outside-in
45. Ubiquitous language
46. Quick & Nimble
47. class DolphinSpec: QuickSpec { override func spec() { it("is friendly") { expect(Dolphin().isFriendly).to(beTruthy()) } it("is smart") { expect(Dolphin().isSmart).to(beTruthy()) } } }
48. describe("a dolphin") { describe("its click") { it("is loud") { let click = Dolphin().click() expect(click.isLoud).to(beTruthy()) } it("has a high frequency") { let click = Dolphin().click() expect(click.hasHighFrequency).to(beTruthy()) } } }
49. describe("a dolphin") { var dolphin: Dolphin! beforeEach { dolphin = Dolphin() } describe("its click") { var click: Click! beforeEach { click = dolphin.click() } it("is loud") { expect(click.isLoud).to(beTruthy()) } it("has a high frequency") { expect(click.hasHighFrequency).to(beTruthy()) } } }
50. describe("its click") { context("when the dolphin is not near anything interesting") { it("is only emitted once") { expect(dolphin!.click().count).to(equal(1)) } } context("when the dolphin is near something interesting") { beforeEach { let ship = SunkenShip() Jamaica.dolphinCove.add(ship) Jamaica.dolphinCove.add(dolphin) } it("is emitted three times") { expect(dolphin.click().count).to(equal(3)) } } }
51. That's about it! Let's dive into code!
52. Assignment 0 » Add data parsing in ChatMessagesUpdater
53. Assignment 1 » Pass data from model object to table view cell
54. That's all folks!