ReSwift 101

Talk I gave at May 29th, 2019 at the UIKonf Unconference

Transcript

1. ReSwi! https://github.com/ReSwift/ReSwift
2. About me — ! iOS developer since ~2013 — In my free time I — " enjoy bouldering — # host a pub quiz — $ travel a lot — % Programming languages & developer tools — ❤ Swift is my favorite — ✅ Loooove green checkmarks in tests — ( Twitter: @xavierLowmiller
3. Agenda 1. Basics 1. Entities 2. Observing 3. Actions 2. Testing 1. Observers 2. Reducers 3. About the library 4. Closing Thoughts
4. https://github.com/xavierLowmiller/reswift-todo
5. Basics
7. State struct AppState: StateType, Equatable { var todos: [Todo] = [] } let store = Store(reducer: appReducer, state: AppState())
9. Observing extension ViewController: StoreSubscriber { func newState(state: [Todo]) { dataSource.todos = state tableView.reloadData() } }
10. Observing override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) store.subscribe(self) } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) store.unsubscribe(self) }
11. Observing override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) store.subscribe(self) { subscription in subscription .select { $0.todos } .skipRepeats() } } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) store.unsubscribe(self) }
13. Actions enum TodoAction: Action { case add(Todo) case update(Todo) case remove(Todo) }
14. @objc func didTapDoneButton() { let action = TodoAction.add(todo) store.dispatch(action) dismiss(animated: true) }
16. Reducers func appReducer(action: Action, state: AppState?) -> AppState { var state = // switch action { case let TodoAction.add(todo): if !state.todos.contains(todo) { state.todos.append(todo) } case ...:// } return state }
17. Testing
18. Observers var actions: [Action] = [] override func setUp() { super.setUp() store.dispatchFunction = { self.actions.append($0) } }
19. Observers func testTappingTheDeleteButtonShouldDispatchARemoveAction() { // Given XCTAssert(actions.isEmpty) viewController.todo = Todo() // When viewController.deleteButton.sendActions(for: .touchUpInside) // Then XCTAssertEqual(actions.count, 1) guard let action = actions[0] as? TodoAction, case let TodoAction.remove(todo) = action else { XCTFail("Wrong Action fired"); return } XCTAssertEqual(todo, viewController.todo) }
20. Reducers func testReducerRemoveShouldRemoveAnExistingTodo() { // Given let state = AppState() let todo = Todo() var newState = appReducer(action: TodoAction.add(todo), state: state) XCTAssertEqual(newState.todos.count, 1) // When let action = TodoAction.remove(todo) newState = appReducer(action: action, state: newState) // Then XCTAssert(newState.todos.isEmpty) }
21. About the library
22. cloc ReSwift 14 text files. 14 unique files. 1 file ignored. ------------------------------------------------------------------------------- Language files blank comment code ------------------------------------------------------------------------------- Swift 12 136 320 343 C/C++ Header 1 4 10 3 ------------------------------------------------------------------------------- SUM: 13 140 330 346 -------------------------------------------------------------------------------
23. cloc ReSwiftTests 12 text files. 12 unique files. 1 file ignored. ------------------------------------------------------------------------------- Language files blank comment code ------------------------------------------------------------------------------- Swift 11 316 225 955 ------------------------------------------------------------------------------- SUM: 11 316 225 955 -------------------------------------------------------------------------------
24. Maintainers @benjaminencz @karlbowden @ARendtslev @ctietze @mjarvis
25. Closing Thoughts — Really small lib (~350 LoC Sources, ~950 LoC Tests) — Try building something small with ReSwift (it's fun!)
26. Thank You