mirror of
https://github.com/facebook/react.git
synced 2025-11-01 09:12:30 +00:00
Andrew Clark
9a52cc8bcd
I'm in the process of codemodding our test suite to the waitFor pattern. See #26285 for full context. This module required a lot of manual changes so I'm doing it as its own PR. The reason is that most of the tests involved simulating an async import by wrapping them in `Promise.resolve()`, which means they would immediately resolve the next time the microtask queue was flushed. I rewrote the tests to resolve the simulated import explicitly. While converting these tests, I also realized that the `waitFor` helpers weren't properly waiting for the entire microtask queue to recursively finish — if a microtask schedules another microtask, the subsequent one wouldn't fire until after `waitFor` had resolved. To fix this, I used the same strategy as `act` — wait for a real task to finish before proceeding, such as a message event.
51 lines
1.9 KiB
JavaScript
51 lines
1.9 KiB
JavaScript
/**
|
|
* Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*
|
|
* @flow
|
|
*/
|
|
|
|
let didWarnAboutMessageChannel = false;
|
|
let enqueueTaskImpl = null;
|
|
|
|
// Same as shared/enqeuueTask, but while that one used by the public
|
|
// implementation of `act`, this is only used by our internal testing helpers.
|
|
export default function enqueueTask(task: () => void): void {
|
|
if (enqueueTaskImpl === null) {
|
|
try {
|
|
// read require off the module object to get around the bundlers.
|
|
// we don't want them to detect a require and bundle a Node polyfill.
|
|
const requireString = ('require' + Math.random()).slice(0, 7);
|
|
const nodeRequire = module && module[requireString];
|
|
// assuming we're in node, let's try to get node's
|
|
// version of setImmediate, bypassing fake timers if any.
|
|
enqueueTaskImpl = nodeRequire.call(module, 'timers').setImmediate;
|
|
} catch (_err) {
|
|
// we're in a browser
|
|
// we can't use regular timers because they may still be faked
|
|
// so we try MessageChannel+postMessage instead
|
|
enqueueTaskImpl = function (callback: () => void) {
|
|
if (__DEV__) {
|
|
if (didWarnAboutMessageChannel === false) {
|
|
didWarnAboutMessageChannel = true;
|
|
if (typeof MessageChannel === 'undefined') {
|
|
console['error'](
|
|
'This browser does not have a MessageChannel implementation, ' +
|
|
'so enqueuing tasks via await act(async () => ...) will fail. ' +
|
|
'Please file an issue at https://github.com/facebook/react/issues ' +
|
|
'if you encounter this warning.',
|
|
);
|
|
}
|
|
}
|
|
}
|
|
const channel = new MessageChannel();
|
|
channel.port1.onmessage = callback;
|
|
channel.port2.postMessage(undefined);
|
|
};
|
|
}
|
|
}
|
|
return enqueueTaskImpl(task);
|
|
}
|