Unit Testing for Designers

I gave this talk at the Playgrounds Conference in Melbourne, Australia, February 2017. Video should be up in a month or two!

Transcript

1. @tamarshmallows
2. Unit testing for designers Tamar "Tim Tam" Nachmany @tamarshmallows
3. @tamarshmallows
4. Design is incredibly important at Tumblr. @tamarshmallows
5. @tamarshmallows
6. @tamarshmallows
7. You're at teacher training @tamarshmallows
8. Using unit testing to teach modularity & architecture Overview - What is unit testing? - What is modularity? - How does unit testing impact software architecture? - Modularity and change - Why? @tamarshmallows
9. What is unit testing? @tamarshmallows
10. Software development is the expansion and adaptation of a system @tamarshmallows
11. Software development is the reuse of logic and types across a system @tamarshmallows
12. definition: Unit tests validate individual units of code by executing logic and asserting expected results @tamarshmallows
13. A unit is An isolated piece of code @tamarshmallows
14. Unit testing is a vehicle for change @tamarshmallows
15. Unit testing automates identifying new issues @tamarshmallows
16. Not all software can be unit tested @tamarshmallows
17. Presentation logic func present(photoLibrary: PhotoLibraryViewController) { switch photoLibrary.configuration { case .iMessage: // Add photo library as child case .Compose: // Present photo library modally } } @tamarshmallows
18. Presentation logic testing func testPhotoLibraryPresentationForiMessageConfiguration() { // Make a presenting view controller let presentingViewController = PresentingViewController() // Make a photo library view controller let photoLibrary = PhotoLibraryViewController(configuration: .iMessage) // 'Present' photo library presentingViewController.present(photoLibrary: photoLibrary) // Assert that photo library was added as a child view controller XCTAssertEqual(photoLibrary.parentViewController, presentingViewController) } @tamarshmallows
19. Tests reflect the construction of a codebase or type @tamarshmallows
20. What is modularity? @tamarshmallows
21. Modularity is how units become units @tamarshmallows
22. Definition: The principle that a type should serve a specific defined purpose and have minimal dependencies @tamarshmallows
23. View Model Parser Data Source Presenter Determiner Provider @tamarshmallows
24. Minimal dependencies @tamarshmallows
25. Modular code is: 1. Easier to understand 2. Easier to unit test 3. Easier to change? @tamarshmallows
26. The purpose of a single-purpose type is easier to understand @tamarshmallows
27. Developers communicate through abstractions @tamarshmallows
28. Like designers, we negotiate innovation & communication @tamarshmallows
29. How does unit testing impact software architecture? @tamarshmallows
30. Testing promotes safety @tamarshmallows
31. What is safety? @tamarshmallows
32. Safety is the reduction of bugs and crashes @tamarshmallows
33. Safety is the reduction of chaos @tamarshmallows
34. Developers are highly focused on how change happens @tamarshmallows
35. When a change happens, does it reuse code? Is that code tested? @tamarshmallows
36. Designing a test is a type of abstraction @tamarshmallows
37. You needs state to validate Where does that 'exposure' come from? A parameter? A property? @tamarshmallows
38. Modularity and change @tamarshmallows
39. Understanding software development means understanding change @tamarshmallows
40. Does modularity make code easier or harder to change? @tamarshmallows
41. Modular code is strict by design @tamarshmallows
42. Modularity makes a type easier to reuse but harder to change @tamarshmallows
43. But testing fundamentally makes change easier @tamarshmallows
44. Prototyping isn't just about speed @tamarshmallows
45. It's about an app's foundations @tamarshmallows
46. Why? @tamarshmallows
47. Innovation Don't learn by example: be the example @tamarshmallows
48. Seeing the future is good for software @tamarshmallows
49. Software architecture is design @tamarshmallows
50. Collaboration @tamarshmallows
51. Let's build a beautiful system together @tamarshmallows
52. Say hello. @tamarshmallows @tamarshmallows
53. Featured artists Rodrigo Tello Ola Szmida Patrick Sluiter Hannah Langford Berman Dai Ruiz Alastair Gray Joel Plosz Mathew Lucas Susanna Bauer Kennedy Dickerson @tamarshmallows