/**

 * 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;

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);

}