Testing React.js Applications

1. Testing React.js Applications Max Stoiber - @mxstbr
2. Max Stoiber Max Stoiber – @mxstbr – mxstbr.com Freelance Front-End Developer @mxstbr
3. Max Stoiber – @mxstbr – mxstbr.com
4. TYPES Max Stoiber – @mxstbr – mxstbr.com
5. SYSTEM TESTING Max Stoiber – @mxstbr – mxstbr.com STRESS TESTING PERFORMANCE TESTING USABILITY TESTING UNIT TESTING
6. Max Stoiber – @mxstbr – mxstbr.com UNIT TESTING UNIT TESTING SYSTEM TESTING STRESS TESTING PERFORMANCE TESTING USABILITY TESTING
7. Max Stoiber – @mxstbr – mxstbr.com UNIT
8. Max Stoiber – @mxstbr – mxstbr.com FUNCTION COMPONENT ACTIONS STORES
9. WHY? Max Stoiber – @mxstbr – mxstbr.com
10. CATCH BUGS BEFORE THEY HAPPEN Max Stoiber – @mxstbr – mxstbr.com
11. EXECUTABLE DOCUMENTATION Max Stoiber – @mxstbr – mxstbr.com
12. SAVE TIME Max Stoiber – @mxstbr – mxstbr.com
13. WRITE BETTER CODE Max Stoiber – @mxstbr – mxstbr.com
14. HOW? Max Stoiber – @mxstbr – mxstbr.com
15. MOCHA Max Stoiber – @mxstbr – mxstbr.com
16. Max Stoiber – @mxstbr – mxstbr.com
17. MJACKSON/EXPECT Max Stoiber – @mxstbr – mxstbr.com
18. Max Stoiber – @mxstbr – mxstbr.com
19. Max Stoiber – @mxstbr – mxstbr.com // add.js export function add(x, y) { return x + y; }
20. Max Stoiber – @mxstbr – mxstbr.com // add.test.js import { add } from './add.js'; import expect from 'expect'; describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
21. Max Stoiber – @mxstbr – mxstbr.com describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
22. Max Stoiber – @mxstbr – mxstbr.com describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
23. Max Stoiber – @mxstbr – mxstbr.com describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
24. Max Stoiber – @mxstbr – mxstbr.com describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
25. Max Stoiber – @mxstbr – mxstbr.com describe('add()', () => { it('adds two numbers', () => { expect(add(2, 3)).toEqual(5); }); it('doesnt add the third number', () => { expect(add(2, 3, 5)).toEqual(add(2, 3)); }); });
26. Max Stoiber – @mxstbr – mxstbr.com
27. Max Stoiber – @mxstbr – mxstbr.com // add.js export function add(x, y) { return x + y; }
28. Max Stoiber – @mxstbr – mxstbr.com // add.js export function add(x, y) { return x + y; x * y; }
29. Max Stoiber – @mxstbr – mxstbr.com
30. Max Stoiber – @mxstbr – mxstbr.com
31. REDUX Max Stoiber – @mxstbr – mxstbr.com
32. NavBar ├── NavBar.react.js # React component │ ├── NavBar.actions.js # Actions ├── NavBar.constants.js # Constants ├── NavBar.reducer.js # Reducer │ ├── NavBar.actions.test.js # Actions tests └── NavBar.reducer.test.js # Reducer tests Max Stoiber – @mxstbr – mxstbr.com
33. ACTIONS Max Stoiber – @mxstbr – mxstbr.com
34. Max Stoiber – @mxstbr – mxstbr.com // NavBar.actions.js import { TOGGLE_NAV } from './NavBar.constants.js'; export function toggleNav() { return { type: TOGGLE_NAV }; }
35. Max Stoiber – @mxstbr – mxstbr.com // NavBar.actions.test.js import { toggleNav } from './NavBar.actions'; import { TOGGLE_NAV } from './NavBar.constants'; import expect from ‘expect'; describe('NavBar actions', () => { });
36. Max Stoiber – @mxstbr – mxstbr.com describe('NavBar actions', () => { describe('toggleNav', () => { it('should return the correct constant', () => { expect(toggleNav()).toEqual({ type: TOGGLE_NAV }); }); }); });
37. Max Stoiber – @mxstbr – mxstbr.com describe('NavBar actions', () => { describe('toggleNav', () => { it('should return the correct constant', () => { expect(toggleNav()).toEqual({ type: TOGGLE_NAV }); }); }); });
38. Max Stoiber – @mxstbr – mxstbr.com describe('NavBar actions', () => { describe('toggleNav', () => { it('should return the correct constant', () => { expect(toggleNav()).toEqual({ type: TOGGLE_NAV }); }); }); });
39. Max Stoiber – @mxstbr – mxstbr.com describe('NavBar actions', () => { describe('toggleNav', () => { it('should return the correct constant', () => { expect(toggleNav()).toEqual({ type: TOGGLE_NAV }); }); }); });
40. Max Stoiber – @mxstbr – mxstbr.com describe('NavBar actions', () => { describe('toggleNav', () => { it('should return the correct constant', () => { expect(toggleNav()).toEqual({ type: TOGGLE_NAV }); }); }); });
41. Max Stoiber – @mxstbr – mxstbr.com
42. REDUCER Max Stoiber – @mxstbr – mxstbr.com
43. Max Stoiber – @mxstbr – mxstbr.com // NavBar.reducer.js import { TOGGLE_NAV } from ‘./NavBar.constants.js'; const initialState = { open: false }; export default function NavBarReducer(state = initialState, action) { switch (action.type) { case TOGGLE_NAV: return Object.assign({}, state, { open: !state.open }); default: return state; } }
44. Max Stoiber – @mxstbr – mxstbr.com // NavBar.reducer.test.js import expect from 'expect'; import NavBarReducer from './NavBar.reducer'; import { TOGGLE_NAV } from './NavBar.constants'; import { toggleNav } from './NavBar.actions'; describe('NavBarReducer', () => { it('returns the initial state', () => {}); it('handles the toggleNav action', () => {}); });
45. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
46. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
47. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
48. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
49. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
50. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
51. Max Stoiber – @mxstbr – mxstbr.com describe('NavBarReducer', () => { it('returns the initial state', () => { expect(NavBarReducer(undefined, {})).toEqual({ open: false }); }); it('handles the toggleNav action', () => { expect(NavBarReducer(undefined, toggleNav())).toEqual({ open: true }); }); });
52. Max Stoiber – @mxstbr – mxstbr.com
53. Max Stoiber – @mxstbr – mxstbr.com
54. AIRBNB/ENZYME Max Stoiber – @mxstbr – mxstbr.com
55. AIRBNB/ENZYME Max Stoiber – @mxstbr – mxstbr.com
56. Max Stoiber – @mxstbr – mxstbr.com // Button.react.js import React from 'react'; class Button extends React.Component { render() { return ( <button className="btn" onClick={this.props.onClick}> { this.props.children } </button> ); } } export default Button;
57. Max Stoiber – @mxstbr – mxstbr.com <Button onClick={this._click}>Click me!</Button>
58. Max Stoiber – @mxstbr – mxstbr.com <button>Click me!</button>
59. Max Stoiber – @mxstbr – mxstbr.com // Button.test.js import Button from './Button.react'; import expect from 'expect'; import { shallow } from 'enzyme'; import React from 'react'; describe('<Button />', () => { it('renders a <button>', () => {}); it('renders text', () => {}); it('handles clicks', () => {}); });
60. Max Stoiber – @mxstbr – mxstbr.com // Button.test.js import Button from './Button.react'; import expect from 'expect'; import { shallow } from 'enzyme'; import React from 'react'; describe('<Button />', () => { it('renders a <button>', () => {}); it('renders text', () => {}); it('handles clicks', () => {}); });
61. SHALLOW RENDERING Max Stoiber – @mxstbr – mxstbr.com
62. ONE LEVEL DEEP Max Stoiber – @mxstbr – mxstbr.com
63. Max Stoiber – @mxstbr – mxstbr.com <div> <span className=“heading">Title</span> <Subcomponent /> </div>
64. Max Stoiber – @mxstbr – mxstbr.com <div> <span class=“heading">Title</span> <div></div> </div> NORMAL RENDERING
65. Max Stoiber – @mxstbr – mxstbr.com <div> <span class=“heading">Title</span> <Subcomponent /> </div> SHALLOW RENDERING
66. Max Stoiber – @mxstbr – mxstbr.com // Button.test.js import Button from './Button.react'; import expect from 'expect'; import { shallow } from 'enzyme'; import React from 'react'; describe('<Button />', () => { it('renders a <button>', () => {}); it('renders text', () => {}); it('handles clicks', () => {}); });
67. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders a <button>', () => { const renderedComponent = shallow( <Button></Button> ); expect( renderedComponent.find("button").node ).toExist(); }); });
68. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders a <button>', () => { const renderedComponent = shallow( <Button></Button> ); expect( renderedComponent.find("button").node ).toExist(); }); });
69. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders a <button>', () => { const renderedComponent = shallow( <Button></Button> ); expect( renderedComponent.find("button").node ).toExist(); }); });
70. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders a <button>', () => { const renderedComponent = shallow( <Button></Button> ); expect( renderedComponent.find("button").node ).toExist(); }); });
71. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders text', () => { const text = "Click me!"; const renderedComponent = shallow( <Button>{ text }</Button> ); expect( renderedComponent.contains(text) ).toEqual(true); }); });
72. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders text', () => { const text = "Click me!"; const renderedComponent = shallow( <Button>{ text }</Button> ); expect( renderedComponent.contains(text) ).toEqual(true); }); });
73. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders text', () => { const text = "Click me!"; const renderedComponent = shallow( <Button>{ text }</Button> ); expect( renderedComponent.contains(text) ).toEqual(true); }); });
74. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders text', () => { const text = "Click me!"; const renderedComponent = shallow( <Button>{ text }</Button> ); expect( renderedComponent.contains(text) ).toEqual(true); }); });
75. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('renders text', () => { const text = "Click me!"; const renderedComponent = shallow( <Button>{ text }</Button> ); expect( renderedComponent.contains(text) ).toEqual(true); }); });
76. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('handles clicks', () => { const onClickSpy = expect.createSpy(); const renderedComponent = shallow( <Button onClick={onClickSpy} /> ); renderedComponent.find('button').simulate('click'); expect(onClickSpy).toHaveBeenCalled(); }); });
77. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('handles clicks', () => { const onClickSpy = expect.createSpy(); const renderedComponent = shallow( <Button onClick={onClickSpy} /> ); renderedComponent.find('button').simulate('click'); expect(onClickSpy).toHaveBeenCalled(); }); });
78. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('handles clicks', () => { const onClickSpy = expect.createSpy(); const renderedComponent = shallow( <Button onClick={onClickSpy} /> ); renderedComponent.find('button').simulate('click'); expect(onClickSpy).toHaveBeenCalled(); }); });
79. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('handles clicks', () => { const onClickSpy = expect.createSpy(); const renderedComponent = shallow( <Button onClick={onClickSpy} /> ); renderedComponent.find('button').simulate('click'); expect(onClickSpy).toHaveBeenCalled(); }); });
80. Max Stoiber – @mxstbr – mxstbr.com describe('<Button />', () => { it('handles clicks', () => { const onClickSpy = expect.createSpy(); const renderedComponent = shallow( <Button onClick={onClickSpy} /> ); renderedComponent.find('button').simulate('click'); expect(onClickSpy).toHaveBeenCalled(); }); });
81. Max Stoiber – @mxstbr – mxstbr.com
82. @mxstbr Max Stoiber – @mxstbr – mxstbr.com HTTPS://GITHUB.COM/MXSTBR/REACT-TESTING