code: function getJsSource(chunk, jsName) {
    let jsSource;
    for (let i = 0, ii = chunk.modules.length; i < ii; ++i) {
      const module = chunk.modules[i];
      if (module.modules) {
        jsSource = getJsSource(module, jsName);
        if (jsSource) {
          return jsSource;
        }
      }
      if (module.identifier.endsWith(jsName) && module.source) {
        return module.source;
      }
    }
  }
docs: Gets the source for the chunk that matches the jsPath
  @param {Object} chunk Chunk.
  @param {string} jsName Name of the file.
  @return {string} The source.