Method _persist

packages/jest-haste-map/src/index.ts:736–738

* 4. serialize the new `HasteMap` in a cache file.

(hasteMap: InternalHasteMap)

   * 4. serialize the new `HasteMap` in a cache file.
   */
  private _persist(hasteMap: InternalHasteMap) {
    writeFileSync(this._cachePath, serialize(hasteMap));
  }

  /**
   * Creates workers or parses files and extracts metadata in-process.