Export a method which return an instance with any config

GoogleAuth.ts

export async function installGoogleAuth(options: any): Promise<any> {
  // set config
  let GoogleAuthConfig: any = null;
  const GoogleAuthDefaultConfig = {
    scope: 'profile email'
  };
  let prompt = 'select_account';
  if (typeof options === 'object') {
    GoogleAuthConfig = Object.assign(GoogleAuthDefaultConfig, options);
    if (options.scope) {
      GoogleAuthConfig.scope = options.scope;
    }
    if (options.prompt) {
      prompt = options.prompt;
    }
    if (!options.clientId) {
      // tslint:disable-next-line
      console.warn('clientId is required');
    }
  } else {
    // tslint:disable-next-line
    console.warn('invalid option type. Object type accepted only');
  }
  await googleAuth.load(GoogleAuthConfig, prompt);
  return googleAuth;
}