Function findUp

packages/angular/cli/src/utilities/find-up.ts:19–44

(names: string | string[], from: string)

 * @returns The path to the first match found, or `null` if no match was found.
 */
export async function findUp(names: string | string[], from: string): Promise<string | null> {
  const filenames = Array.isArray(names) ? names : [names];

  let currentDir = resolve(from);
  while (true) {
    for (const name of filenames) {
      const p = join(currentDir, name);
      try {
        await stat(p);

        return p;
      } catch {
        // Ignore errors (e.g. file not found).
      }
    }

    const parentDir = dirname(currentDir);
    if (parentDir === currentDir) {
      break;
    }

    currentDir = parentDir;
  }

  return null;
}

/**
 * Synchronously find a file or directory by walking up the directory tree.