useSyncExternalStoreNative-test.js — react Source File

Source Code

/**
 * 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.
 *
 * @emails react-core
 *
 * @jest-environment node
 */

'use strict';

let React;
let ReactNoop;
let Scheduler;
let useSyncExternalStore;
let useSyncExternalStoreWithSelector;
let act;
let assertLog;

// This tests the userspace shim of `useSyncExternalStore` in a server-rendering
// (Node) environment
describe('useSyncExternalStore (userspace shim, server rendering)', () => {
  beforeEach(() => {
    jest.resetModules();

    // Remove useSyncExternalStore from the React imports so that we use the
    // shim instead. Also removing startTransition, since we use that to detect
    // outdated 18 alphas that don't yet include useSyncExternalStore.
    //
    // Longer term, we'll probably test this branch using an actual build of
    // React 17.
    jest.mock('react', () => {
      const {
        startTransition: _,
        useSyncExternalStore: __,
        ...otherExports
      } = jest.requireActual('react');
      return otherExports;
    });

    jest.mock('use-sync-external-store/shim', () =>
      jest.requireActual('use-sync-external-store/shim/index.native'),
    );

    React = require('react');
    ReactNoop = require('react-noop-renderer');
    Scheduler = require('scheduler');
    act = require('internal-test-utils').act;

    const InternalTestUtils = require('internal-test-utils');
    assertLog = InternalTestUtils.assertLog;

    if (gate(flags => flags.source)) {
      // The `shim/with-selector` module composes the main
      // `use-sync-external-store` entrypoint. In the compiled artifacts, this
      // is resolved to the `shim` implementation by our build config, but when
      // running the tests against the source files, we need to tell Jest how to
      // resolve it. Because this is a source module, this mock has no affect on
// ... (123 more lines)