Vercel cors helper

vercel-cors.ts

export function cors(fn: NextApiHandler, methods = ['GET']) {
  return async (request: NextApiRequest, response: NextApiResponse) => {
    const allowedMethods = [...methods, 'OPTIONS'].join(',');

    response.setHeader('Access-Control-Allow-Credentials', 'true');
    response.setHeader('Access-Control-Allow-Origin', '*');
    response.setHeader('Access-Control-Allow-Methods', allowedMethods);
    response.setHeader(
      'Access-Control-Allow-Headers',
      'X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Authorization, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version',
    );

    if (request.method === 'OPTIONS') {
      return response.status(200).end();
    }

    return fn(request, response);
  };
}