| 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 | let React; |
| 13 | |
| 14 | let ReactDOMClient; |
| 15 | let act; |
| 16 | let assertLog; |
| 17 | let Scheduler; |
| 18 | |
| 19 | describe('ReactDOMSafariMicrotaskBug-test', () => { |
| 20 | let container; |
| 21 | let overrideQueueMicrotask; |
| 22 | let flushFakeMicrotasks; |
| 23 | |
| 24 | beforeEach(() => { |
| 25 | // In Safari, microtasks don't always run on clean stack. |
| 26 | // This setup crudely approximates it. |
| 27 | // In reality, the sync flush happens when an iframe is added to the page. |
| 28 | // https://github.com/facebook/react/issues/22459 |
| 29 | const originalQueueMicrotask = queueMicrotask; |
| 30 | overrideQueueMicrotask = false; |
| 31 | const fakeMicrotaskQueue = []; |
| 32 | global.queueMicrotask = cb => { |
| 33 | if (overrideQueueMicrotask) { |
| 34 | fakeMicrotaskQueue.push(cb); |
| 35 | } else { |
| 36 | originalQueueMicrotask(cb); |
| 37 | } |
| 38 | }; |
| 39 | flushFakeMicrotasks = () => { |
| 40 | while (fakeMicrotaskQueue.length > 0) { |
| 41 | const cb = fakeMicrotaskQueue.shift(); |
| 42 | cb(); |
| 43 | } |
| 44 | }; |
| 45 | |
| 46 | jest.resetModules(); |
| 47 | container = document.createElement('div'); |
| 48 | React = require('react'); |
| 49 | ReactDOMClient = require('react-dom/client'); |
| 50 | act = require('internal-test-utils').act; |
| 51 | assertLog = require('internal-test-utils').assertLog; |
| 52 | Scheduler = require('scheduler'); |
| 53 | |
| 54 | document.body.appendChild(container); |
| 55 | }); |
| 56 | |
| 57 | afterEach(() => { |
| 58 | document.body.removeChild(container); |
| 59 | }); |
| 60 | |
| 61 | it('should deal with premature microtask in commit phase', async () => { |
| 62 | let ran = false; |
| 63 | function Foo() { |
| 64 | const [state, setState] = React.useState(0); |
| 65 | return ( |
| 66 | <div |
| 67 | ref={() => { |
| 68 | overrideQueueMicrotask = true; |
| 69 | if (!ran) { |
| 70 | ran = true; |
| 71 | setState(1); |
| 72 | flushFakeMicrotasks(); |
| 73 | Scheduler.log( |
| 74 | 'Content at end of ref callback: ' + container.textContent, |
| 75 | ); |
| 76 | } |
| 77 | }}> |
| 78 | {state} |
| 79 | </div> |
| 80 | ); |
| 81 | } |
| 82 | const root = ReactDOMClient.createRoot(container); |
| 83 | await act(() => { |
| 84 | root.render(<Foo />); |
| 85 | }); |
| 86 | assertLog(['Content at end of ref callback: 0']); |
| 87 | expect(container.textContent).toBe('1'); |
| 88 | }); |
| 89 | |
| 90 | it('should deal with premature microtask in event handler', async () => { |
| 91 | function Foo() { |
| 92 | const [state, setState] = React.useState(0); |
| 93 | return ( |
| 94 | <button |
| 95 | onClick={() => { |
| 96 | overrideQueueMicrotask = true; |
| 97 | setState(1); |
| 98 | flushFakeMicrotasks(); |
| 99 | Scheduler.log( |
| 100 | 'Content at end of click handler: ' + container.textContent, |
| 101 | ); |
| 102 | }}> |
| 103 | {state} |
| 104 | </button> |
| 105 | ); |
| 106 | } |
| 107 | const root = ReactDOMClient.createRoot(container); |
| 108 | await act(() => { |
| 109 | root.render(<Foo />); |
| 110 | }); |
| 111 | expect(container.textContent).toBe('0'); |
| 112 | await act(() => { |
| 113 | container.firstChild.dispatchEvent( |
| 114 | new MouseEvent('click', {bubbles: true}), |
| 115 | ); |
| 116 | }); |
| 117 | // This causes the update to flush earlier than usual. This isn't the ideal |
| 118 | // behavior but we use this test to document it. The bug is Safari's, not |
| 119 | // ours, so we just do our best to not crash even though the behavior isn't |
| 120 | // completely correct. |
| 121 | assertLog(['Content at end of click handler: 1']); |
| 122 | expect(container.textContent).toBe('1'); |
| 123 | }); |
| 124 | }); |