| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @emails react-core |
| 8 | */ |
| 9 | |
| 10 | 'use strict'; |
| 11 | |
| 12 | describe('ReactStrictMode', () => { |
| 13 | let React; |
| 14 | let ReactDOMClient; |
| 15 | let act; |
| 16 | |
| 17 | beforeEach(() => { |
| 18 | jest.resetModules(); |
| 19 | React = require('react'); |
| 20 | ReactDOMClient = require('react-dom/client'); |
| 21 | |
| 22 | act = require('internal-test-utils').act; |
| 23 | }); |
| 24 | |
| 25 | describe('levels', () => { |
| 26 | let log; |
| 27 | |
| 28 | beforeEach(() => { |
| 29 | log = []; |
| 30 | }); |
| 31 | |
| 32 | function Component({label}) { |
| 33 | React.useEffect(() => { |
| 34 | log.push(`${label}: useEffect mount`); |
| 35 | return () => log.push(`${label}: useEffect unmount`); |
| 36 | }); |
| 37 | |
| 38 | React.useLayoutEffect(() => { |
| 39 | log.push(`${label}: useLayoutEffect mount`); |
| 40 | return () => log.push(`${label}: useLayoutEffect unmount`); |
| 41 | }); |
| 42 | |
| 43 | log.push(`${label}: render`); |
| 44 | |
| 45 | return null; |
| 46 | } |
| 47 | |
| 48 | it('should default to not strict', async () => { |
| 49 | await act(() => { |
| 50 | const container = document.createElement('div'); |
| 51 | const root = ReactDOMClient.createRoot(container); |
| 52 | root.render(<Component label="A" />); |
| 53 | }); |
| 54 | |
| 55 | expect(log).toEqual([ |
| 56 | 'A: render', |
| 57 | 'A: useLayoutEffect mount', |
| 58 | 'A: useEffect mount', |
| 59 | ]); |
| 60 | }); |
| 61 | |
| 62 | if (__DEV__) { |
| 63 | it('should support enabling strict mode via createRoot option', async () => { |
| 64 | await act(() => { |
| 65 | const container = document.createElement('div'); |
| 66 | const root = ReactDOMClient.createRoot(container, { |
| 67 | unstable_strictMode: true, |
| 68 | }); |
| 69 | root.render(<Component label="A" />); |
| 70 | }); |
| 71 | |
| 72 | expect(log).toEqual([ |
| 73 | 'A: render', |
| 74 | 'A: render', |
| 75 | 'A: useLayoutEffect mount', |
| 76 | 'A: useEffect mount', |
| 77 | 'A: useLayoutEffect unmount', |
| 78 | 'A: useEffect unmount', |
| 79 | 'A: useLayoutEffect mount', |
| 80 | 'A: useEffect mount', |
| 81 | ]); |
| 82 | }); |
| 83 | |
| 84 | it('should include legacy + strict effects mode', async () => { |
| 85 | await act(() => { |
| 86 | const container = document.createElement('div'); |
| 87 | const root = ReactDOMClient.createRoot(container); |
| 88 | root.render( |
| 89 | <React.StrictMode> |
| 90 | <Component label="A" /> |
| 91 | </React.StrictMode>, |
| 92 | ); |
| 93 | }); |
| 94 | |
| 95 | expect(log).toEqual([ |
| 96 | 'A: render', |
| 97 | 'A: render', |
| 98 | 'A: useLayoutEffect mount', |
| 99 | 'A: useEffect mount', |
| 100 | 'A: useLayoutEffect unmount', |
| 101 | 'A: useEffect unmount', |
| 102 | 'A: useLayoutEffect mount', |
| 103 | 'A: useEffect mount', |
| 104 | ]); |
| 105 | }); |
| 106 | |
| 107 | it('should allow level to be increased with nesting', async () => { |
| 108 | await act(() => { |
| 109 | const container = document.createElement('div'); |
| 110 | const root = ReactDOMClient.createRoot(container); |
| 111 | root.render( |
| 112 | <> |
| 113 | <Component label="A" /> |
| 114 | <React.StrictMode> |
| 115 | <Component label="B" />, |
| 116 | </React.StrictMode> |
| 117 | , |
| 118 | </>, |
| 119 | ); |
| 120 | }); |
| 121 | |
| 122 | expect(log).toEqual([ |
| 123 | 'A: render', |
| 124 | 'B: render', |
| 125 | 'B: render', |
| 126 | 'A: useLayoutEffect mount', |
| 127 | 'B: useLayoutEffect mount', |
| 128 | 'A: useEffect mount', |
| 129 | 'B: useEffect mount', |
| 130 | 'B: useLayoutEffect unmount', |
| 131 | 'B: useEffect unmount', |
| 132 | 'B: useLayoutEffect mount', |
| 133 | 'B: useEffect mount', |
| 134 | ]); |
| 135 | }); |
| 136 | |
| 137 | it('should support nested strict mode on initial mount', async () => { |
| 138 | function Wrapper({children}) { |
| 139 | return children; |
| 140 | } |
| 141 | await act(() => { |
| 142 | const container = document.createElement('div'); |
| 143 | const root = ReactDOMClient.createRoot(container); |
| 144 | root.render( |
| 145 | <Wrapper> |
| 146 | <Component label="A" /> |
| 147 | <React.StrictMode> |
| 148 | <Component label="B" />, |
| 149 | </React.StrictMode> |
| 150 | , |
| 151 | </Wrapper>, |
| 152 | ); |
| 153 | }); |
| 154 | |
| 155 | expect(log).toEqual([ |
| 156 | 'A: render', |
| 157 | 'B: render', |
| 158 | 'B: render', |
| 159 | 'A: useLayoutEffect mount', |
| 160 | 'B: useLayoutEffect mount', |
| 161 | 'A: useEffect mount', |
| 162 | 'B: useEffect mount', |
| 163 | // TODO: this is currently broken |
| 164 | // 'B: useLayoutEffect unmount', |
| 165 | // 'B: useEffect unmount', |
| 166 | // 'B: useLayoutEffect mount', |
| 167 | // 'B: useEffect mount', |
| 168 | ]); |
| 169 | }); |
| 170 | } |
| 171 | }); |
| 172 | }); |