Function withLocalTmpDir

packages/plugin-lighthouse/src/lib/runner/utils.ts:207–232

(fn: () => Promise<T>)

 * @returns Wrapped function which overrides `TEMP` environment variable, before cleaning up afterwards.
 */
export function withLocalTmpDir<T>(fn: () => Promise<T>): () => Promise<T> {
  if (os.platform() !== 'win32') {
    return fn;
  }

  return async () => {
    const originalTmpDir = process.env['TEMP'];
    const localPath = path.join(pluginWorkDir(LIGHTHOUSE_PLUGIN_SLUG), 'tmp');

    // eslint-disable-next-line functional/immutable-data
    process.env['TEMP'] = localPath;
    logger.debug(
      `Temporarily overwriting TEMP environment variable with ${localPath} to prevent permissions error on cleanup`,
    );

    try {
      return await fn();
    } finally {
      // eslint-disable-next-line functional/immutable-data
      process.env['TEMP'] = originalTmpDir;
      logger.debug(
        `Restored TEMP environment variable to original value ${originalTmpDir}`,
      );
    }
  };
}