Method _readManifest

tests/helpers/package-cache.js:288–307

* The `_readManifest` method reads the on-disk manifest for the current * cache and returns its value. * * @private * @method _readManifest * @param {String} label The label for the cache. * @param {String} type The type of package cache. * @return {String} The manifest file con

(label, type)

   * @return {String} The manifest file contents on disk.
   */
  _readManifest(label, type) {
    let readManifestDir = this.dirs[label];

    if (!readManifestDir) {
      return null;
    }

    let inputPath = path.join(readManifestDir, translate(type, 'manifest'));

    let result = null;
    try {
      result = fs.readFileSync(inputPath, 'utf8');
    } catch (error) {
      // Swallow non-exceptional errors.
      if (error.code !== 'ENOENT') {
        throw error;
      }
    }
    return result;
  }

  /**
   * The `_writeManifest` method generates the on-disk folder for the package cache