node: setAllowHeader()

setAllowHeader.ts

import { NextFunction, Request, Response } from 'express';

/**
 * Sets Allow header.
 *
 * "The Allow header lists the set of methods support by a resource.
 * This header must be sent if the server responds with a 405 Method Not Allowed
 * status code to indicate which request methods can be used."
 *
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Allow
 */
export const setAllowHeader = (req: Request, res: Response, next: NextFunction) => {
  res.set('allow', 'GET, POST, OPTIONS');
  next();
};