Desenvolvimento guiado por testes no Android com MVP.

Transcript

1. Desenvolvimento guiado por testes no Android com MVP. Vinícius Soares - @vinicius5oares
3. Por que usar TDD?
4. Por que usar TDD? Code design
5. Por que usar TDD? Manutenção
6. Por que usar TDD? Documentação
7. Por que usar TDD? É divertido
8. TDD - Test Driven Development
9. TDD - Test Driven Development Write a test that fails
10. TDD - Test Driven Development Write a test that fails Make the code work
11. TDD - Test Driven Development Write a test that fails Make the code work Remove redundancy
12. Model View Presenter
13. Model View Presenter
14. Model View Presenter
15. Model View Presenter
16. Model View Presenter
17. Dagger 2 - Dependency Injection medium.com/android-dev-br/introdução-ao-dagger-2-56d193118a6c
18. RxJava youtube.com/watch?v=0FpphC6hL5I
19. Mockito youtube.com/watch?v=DJDBl0vURD4
20. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ }
21. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ } Database mockDatabase = Mockito.mock(Database.class);
22. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ } Database mockDatabase = Mockito.mock(Database.class); System.out.print(mockDatabase.getFirstProductName()); // Prints: null Mockito.verify(mockDatabase).getFirstProductName();
23. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ } Database mockDatabase = Mockito.mock(Database.class);
24. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ } Database mockDatabase = Mockito.mock(Database.class); Mockito.when(mockDatabase.getFirstProductName()).thenReturn("Google Pixel"); System.out.print(mockDatabase.getFirstProductName()); // Prints: Google Pixel Mockito.verify(mockDatabase).getFirstProductName();
25. Mockito class Database { String getFirstProductName() { /* ... */ }; /* ... */ } Database mockDatabase = Mockito.mock(Database.class); Mockito.when(mockDatabase.getFirstProductName()).thenReturn("Google Pixel"); System.out.print(mockDatabase.getFirstProductName()); // Prints: Google Pixel Mockito.verify(mockDatabase).getFirstProductName();
26. Talk is cheap. Show me the code!
27. Planning • Mostrar a lista de artigos. • Mostrar um Empty State se a lista estiver vazia.
28. Tests @Test public void loadArticlesReturnsArticles() { }
29. Tests @Test public void loadArticlesReturnsArticles() { List<Article> articles = new ArrayList<>(); articles.add(/* ... */); articles.add(/* ... */); }
30. Tests @Test public void loadArticlesReturnsArticles() { List<Article> articles = new ArrayList<>(); articles.add(/* ... */); articles.add(/* ... */); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); }
31. Tests @Test public void loadArticlesReturnsArticles() { List<Article> articles = new ArrayList<>(); articles.add(/* ... */); articles.add(/* ... */); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); presenter.loadArticles(); }
32. Tests @Test public void loadArticlesReturnsArticles() { List<Article> articles = new ArrayList<>(); articles.add(/* ... */); articles.add(/* ... */); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); presenter.loadArticles(); Mockito.verify(mockView).showArticles(articles); }
33. Tests @Test public void loadArticlesReturnsArticles() { List<Article> articles = new ArrayList<>(); articles.add(/* ... */); articles.add(/* ... */); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); presenter.loadArticles(); Mockito.verify(mockView).showArticles(articles); Mockito.verify(mockView, never()).showEmptyState(); }
34. Tests @Test public void loadArticlesReturnsEmptyList() { List<Article> articles = new ArrayList<>(); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); }
35. Tests @Test public void loadArticlesReturnsEmptyList() { List<Article> articles = new ArrayList<>(); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); presenter.loadArticles(); }
36. Tests @Test public void loadArticlesReturnsEmptyList() { List<Article> articles = new ArrayList<>(); Mockito.when(mockRepository.getArticles()).thenReturn(Observable.just(articles)); presenter.loadArticles(); Mockito.verify(mockView).showEmptyState(); Mockito.verify(mockView, never()).showArticles(ArgumentMatchers.anyList()); }
37. View interface ArticlesView { void showArticles(List<Articles> articles); void showEmptyState(); }
38. class ArticlesActivity extends AppCompatActivity implements ArticlesView { ArticlesPresenter presenter; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); presenter = new ArticlesPresenter(UserRepository.getInstance()); /* Use dagger */ presenter.attachView(this); } protected onDestroy() { super.onDestroy(); presenter.detachView(); } public void showArticles(List<Articles> articles) { /* ... */ } public void showEmptyState() { /* ... */ } }
39. Presenter class ArticlesPresenter { private ArticlesView view; public void attachView(ArticlesView view) { this.view = view; } public void detachView() { this.view = null; } }
40. Presenter class ArticlesPresenter { private View view; private ArticlesRepository repository; public ArticlesPresenter(ArticlesRepository repository) { this.repository = repository; } public void attachView(View view) { /* ... */ } public void detachView() { /* ... */ } }
41. Presenter public void detachView() { /* ... */ } public void loadArticles() { repository.getArticles() /* ... */ .subscribe(articles -> { if (articles.isEmpty()) view.showArticlesEmptyState(); else view.showArticles(articles); }); } }
42. Model - Simple Example interface ArticlesRepository { @GET("articles") Observable<List<Article>> getArticles(); }
43. Model - Repository Pattern class ArticlesRepository { public Observable<List<Article>> getArticles() { Observable<List<Article>> memory = /* ... */; Observable<List<Article>> database = /* ... */; Observable<List<Article>> api = /* ... */; return Observable .concat(memory, database, api) .first(); } }
44. Links • github.com/googlesamples/android-architecture/tree/todo-mvp-rxjava • github.com/ribot/android-boilerplate • codelabs.developers.google.com/codelabs/android-testing/index.html
45. Próximos passos • Clean Architecture • Espresso & UiAutomator. • Cobertura de Testes • Code Analysis tools • Continuous integration
46. Obrigado :) speakerdeck.com/viniciussoares @vinicius5oares @vinicius-soares