Function resolveConfigPath

packages/jest-config/src/resolveConfigPath.ts:25–65

(
  pathToResolve: string,
  cwd: string,
  skipMultipleConfigError = false,
)

const getConfigFilename = (ext: string) => JEST_CONFIG_BASE_NAME + ext;

export default function resolveConfigPath(
  pathToResolve: string,
  cwd: string,
  skipMultipleConfigError = false,
): string {
  if (!path.isAbsolute(cwd)) {
    throw new Error(`"cwd" must be an absolute path. cwd: ${cwd}`);
  }
  const absolutePath = path.isAbsolute(pathToResolve)
    ? pathToResolve
    : path.resolve(cwd, pathToResolve);

  if (isFile(absolutePath)) {
    return absolutePath;
  }

  // This is a guard against passing non existing path as a project/config,
  // that will otherwise result in a very confusing situation.
  // e.g.
  // With a directory structure like this:
  //   my_project/
  //     package.json
  //
  // Passing a `my_project/some_directory_that_doesnt_exist` as a project
  // name will resolve into a (possibly empty) `my_project/package.json` and
  // try to run all tests it finds under `my_project` directory.
  if (!fs.existsSync(absolutePath)) {
    throw new Error(
      "Can't find a root directory while resolving a config file path.\n" +
        `Provided path to resolve: ${pathToResolve}\n` +
        `cwd: ${cwd}`,
    );
  }

  return resolveConfigPathByTraversing(
    absolutePath,
    pathToResolve,
    cwd,
    skipMultipleConfigError,
  );
}

const resolveConfigPathByTraversing = (
  pathToResolve: string,