metro.config.js

/**
 * Metro configuration for React Native
 * https://github.com/facebook/react-native
 *
 * @format
 */

const path = require('path');

const { FileStore } = require('metro-cache');

const getWorkspaces = require('get-yarn-workspaces');
const blacklist = require('metro-config/src/defaults/exclusionList');

const workspaces = getWorkspaces(__dirname);

const packages = [];

module.exports = {
  projectRoot: path.resolve(__dirname, '.'),

  watchFolders: [
    path.resolve(__dirname, '../../node_modules'),
    ...packages.map(pkg => path.resolve(__dirname, `../${pkg}`)),
  ],

  resolver: {
    blacklistRE: blacklist([
      ...workspaces
        .filter(workspacePath => workspacePath.indexOf('packages/app') === -1)
        .map(workspacePath => new RegExp(`^${escape(path.resolve(__dirname, workspacePath, 'node_modules'))}\\/.*$`)),
      new RegExp(`^${escape(path.resolve(__dirname, '../../node_modules', 'react'))}\\/.*$`),
    ]),
    resolverMainFields: ['react-native-ts', 'browser-ts', 'main-ts', 'react-native', 'browser', 'main'],
    // https://github.com/facebook/metro/issues/1#issuecomment-453450709
    extraNodeModules: new Proxy(
      {},
      {
        get: (target, name) => path.join(process.cwd(), `node_modules/${name}`),
      },
    ),
  },

  // http://facebook.github.io/react-native/blog/2019/03/12/releasing-react-native-059#faster-app-launches-with-inline-requires
  transformer: {
    getTransformOptions: async () => ({
      transform: {
        experimentalImportSupport: false,
        inlineRequires: false,
      },
    }),
  },

  cacheStores: [
    new FileStore({
      root: path.join(__dirname, 'metro-cache'),
    }),
  ],
};