jest.resolver.js

/**
 * Copyright 2023 Comcast Cable Communications Management, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

module.exports = (path, options) => {
  // Call the defaultResolver, so we leverage its cache, error handling, etc.
  return options.defaultResolver(path, {
    ...options,
    // Use packageFilter to process parsed `package.json` before the resolution (see https://www.npmjs.com/package/resolve#resolveid-opts-cb)
    packageFilter: pkg => {
      if (pkg.name.startsWith('@lightning')) {
        delete pkg.exports; // Jest is not properly falling back to index.js if the bundle does not exist in the exports declaration. Removing the exports property all together and relying on the default resolution of the main property in package.json fixes these resolution errors
      }

      return {
        ...pkg,
        // Alter the value of `main` before resolving the package
        main: pkg.module || pkg.main
      };
    }
  });
};