storybook/code/lib/builder-webpack5/templates/virtualModuleModernEntry.js.handlebars

import { global } from '@storybook/global';

import { ClientApi, PreviewWeb, addons, composeConfigs } from '@storybook/preview-api';
import { createChannel as createPostMessageChannel } from '@storybook/channel-postmessage';
import { createChannel as createWebSocketChannel } from '@storybook/channel-websocket';

import { importFn } from './{{storiesFilename}}';

const { SERVER_CHANNEL_URL } = global;

const getProjectAnnotations = () =>
  composeConfigs([{{#each previewAnnotations}}require('{{this}}'),{{/each}}]);

const channel = createPostMessageChannel({ page: 'preview' });
addons.setChannel(channel);

if (SERVER_CHANNEL_URL) {
  const serverChannel = createWebSocketChannel({ url: SERVER_CHANNEL_URL, });
  addons.setServerChannel(serverChannel);
  window.__STORYBOOK_SERVER_CHANNEL__ = serverChannel;
}

const preview = new PreviewWeb();

window.__STORYBOOK_PREVIEW__ = preview;
window.__STORYBOOK_STORY_STORE__ = preview.storyStore;
window.__STORYBOOK_ADDONS_CHANNEL__ = channel;
window.__STORYBOOK_CLIENT_API__ = new ClientApi({ storyStore: preview.storyStore });

preview.initialize({ importFn, getProjectAnnotations });

if (import.meta.webpackHot) {
  import.meta.webpackHot.accept('./{{storiesFilename}}', () => {
    // importFn has changed so we need to patch the new one in
    preview.onStoriesChanged({ importFn });
  });

  import.meta.webpackHot.accept([{{#each previewAnnotations}}'{{this}}',{{/each}}], () => {
    // getProjectAnnotations has changed so we need to patch the new one in
    preview.onGetProjectAnnotationsChanged({ getProjectAnnotations });
  });
}