Function dirname

packages/angular_devkit/core/src/virtual-fs/path.ts:95–104

(path: Path)

 * Return the dirname of the path, as a Path. See path.dirname
 */
export function dirname(path: Path): Path {
  const index = path.lastIndexOf(NormalizedSep);
  if (index === -1) {
    return '' as Path;
  }

  const endIndex = index === 0 ? 1 : index; // case of file under root: '/file'

  return normalize(path.slice(0, endIndex));
}

/**
 * Join multiple paths together, and normalize the result. Accepts strings that will be