| 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 | * @flow |
| 8 | */ |
| 9 | |
| 10 | import {__DEBUG__} from 'react-devtools-shared/src/constants'; |
| 11 | |
| 12 | import type { |
| 13 | Thenable, |
| 14 | FulfilledThenable, |
| 15 | RejectedThenable, |
| 16 | } from 'shared/ReactTypes'; |
| 17 | |
| 18 | import * as React from 'react'; |
| 19 | |
| 20 | const TIMEOUT = 30000; |
| 21 | |
| 22 | type Module = any; |
| 23 | type ModuleLoaderFunction = () => Thenable<Module>; |
| 24 | |
| 25 | // This is intentionally a module-level Map, rather than a React-managed one. |
| 26 | // Otherwise, refreshing the inspected element cache would also clear this cache. |
| 27 | // Modules are static anyway. |
| 28 | const moduleLoaderFunctionToModuleMap: Map<ModuleLoaderFunction, Module> = |
| 29 | new Map(); |
| 30 | function readRecord<T>(record: Thenable<T>): T | null { |
| 31 | if (typeof React.use === 'function') { |
| 32 | try { |
| 33 | // eslint-disable-next-line react-hooks-published/rules-of-hooks |
| 34 | return React.use(record); |
| 35 | } catch (x) { |
| 36 | if (x === null) { |
| 37 | return null; |
| 38 | } |
| 39 | throw x; |
| 40 | } |
| 41 | } |
| 42 | if (record.status === 'fulfilled') { |
| 43 | return record.value; |
| 44 | } else if (record.status === 'rejected') { |
| 45 | return null; |
| 46 | } else { |
| 47 | throw record; |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | // TODO Flow type |
| 52 | export function loadModule(moduleLoaderFunction: ModuleLoaderFunction): Module { |
| 53 | let record = moduleLoaderFunctionToModuleMap.get(moduleLoaderFunction); |
| 54 | |
| 55 | // $FlowFixMe[constant-condition] |
| 56 | if (__DEBUG__) { |
| 57 | console.log( |
| 58 | `[dynamicImportCache] loadModule("${moduleLoaderFunction.name}")`, |
| 59 | ); |
| 60 | } |
| 61 | |
| 62 | if (!record) { |
| 63 | const callbacks = new Set<(value: any) => mixed>(); |
| 64 | const rejectCallbacks = new Set<(reason: mixed) => mixed>(); |
| 65 | const thenable: Thenable<Module> = { |
| 66 | status: 'pending', |
| 67 | value: null, |
| 68 | reason: null, |
| 69 | then(callback: (value: any) => mixed, reject: (error: mixed) => mixed) { |
| 70 | callbacks.add(callback); |
| 71 | rejectCallbacks.add(reject); |
| 72 | }, |
| 73 | |
| 74 | // Optional property, read by React to name this I/O in async debug info: |
| 75 | displayName: `Loading module "${moduleLoaderFunction.name}"`, |
| 76 | }; |
| 77 | |
| 78 | const wake = () => { |
| 79 | if (timeoutID) { |
| 80 | clearTimeout(timeoutID); |
| 81 | timeoutID = null; |
| 82 | } |
| 83 | |
| 84 | // This assumes they won't throw. |
| 85 | callbacks.forEach(callback => callback()); |
| 86 | callbacks.clear(); |
| 87 | rejectCallbacks.clear(); |
| 88 | }; |
| 89 | const wakeRejections = () => { |
| 90 | if (timeoutID) { |
| 91 | clearTimeout(timeoutID); |
| 92 | timeoutID = null; |
| 93 | } |
| 94 | |
| 95 | // This assumes they won't throw. |
| 96 | rejectCallbacks.forEach(callback => callback((thenable as any).reason)); |
| 97 | rejectCallbacks.clear(); |
| 98 | callbacks.clear(); |
| 99 | }; |
| 100 | |
| 101 | record = thenable; |
| 102 | |
| 103 | let didTimeout = false; |
| 104 | |
| 105 | moduleLoaderFunction().then( |
| 106 | module => { |
| 107 | // $FlowFixMe[constant-condition] |
| 108 | if (__DEBUG__) { |
| 109 | console.log( |
| 110 | `[dynamicImportCache] loadModule("${moduleLoaderFunction.name}") then()`, |
| 111 | ); |
| 112 | } |
| 113 | |
| 114 | if (didTimeout) { |
| 115 | return; |
| 116 | } |
| 117 | |
| 118 | const fulfilledThenable: FulfilledThenable<Module> = thenable as any; |
| 119 | fulfilledThenable.status = 'fulfilled'; |
| 120 | fulfilledThenable.value = module; |
| 121 | |
| 122 | wake(); |
| 123 | }, |
| 124 | error => { |
| 125 | // $FlowFixMe[constant-condition] |
| 126 | if (__DEBUG__) { |
| 127 | console.log( |
| 128 | `[dynamicImportCache] loadModule("${moduleLoaderFunction.name}") catch()`, |
| 129 | ); |
| 130 | } |
| 131 | |
| 132 | if (didTimeout) { |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | console.log(error); |
| 137 | |
| 138 | const rejectedThenable: RejectedThenable<Module> = thenable as any; |
| 139 | rejectedThenable.status = 'rejected'; |
| 140 | rejectedThenable.reason = error; |
| 141 | |
| 142 | wakeRejections(); |
| 143 | }, |
| 144 | ); |
| 145 | |
| 146 | // Eventually timeout and stop trying to load the module. |
| 147 | let timeoutID: null | TimeoutID = setTimeout(function onTimeout() { |
| 148 | // $FlowFixMe[constant-condition] |
| 149 | if (__DEBUG__) { |
| 150 | console.log( |
| 151 | `[dynamicImportCache] loadModule("${moduleLoaderFunction.name}") onTimeout()`, |
| 152 | ); |
| 153 | } |
| 154 | |
| 155 | timeoutID = null; |
| 156 | |
| 157 | didTimeout = true; |
| 158 | |
| 159 | const rejectedThenable: RejectedThenable<Module> = thenable as any; |
| 160 | rejectedThenable.status = 'rejected'; |
| 161 | rejectedThenable.reason = null; |
| 162 | |
| 163 | wakeRejections(); |
| 164 | }, TIMEOUT); |
| 165 | |
| 166 | moduleLoaderFunctionToModuleMap.set(moduleLoaderFunction, record); |
| 167 | } |
| 168 | |
| 169 | // $FlowFixMe[underconstrained-implicit-instantiation] |
| 170 | const response = readRecord(record); |
| 171 | return response; |
| 172 | } |