Allow API routes to tie into specific methods

[stramel]

Feature request

Is your feature request related to a problem? Please describe.

Handling various Methods in API routes is tiresome. If I only want to handle POST, I have to do something like

export default async (req: IncomingMessage, res: ServerResponse) => {
  if (req.method !== 'POST') {
    res.status(405).json({
      error: 'Invalid method',
    })
    return
  }

  // Handle POST
}

If I want to handle multiple methods I either have to inline them all or break them into separate functions.

Describe the solution you'd like

I like having the default export as a generic request handler. Expanding on that, it would be nice to have named exports for the various Methods supported. So my above example would become,

export  const post = async (req: IncomingMessage, res: ServerResponse) => {
  // Handle POST
}

[KieraDOG]

import Boom from '@hapi/boom';
import { includes } from 'ramda';

const ALLOWED_METHOD = ['GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'CONNECT', 'OPTIONS', 'TRACE', 'PATCH'];

const withMethod = (method) => (fn) => async (req, res) => {
  const thisMethod = method.toUpperCase();

  if (req.method !== thisMethod || !includes(thisMethod, ALLOWED_METHOD)) {
    const boomified = Boom.methodNotAllowed();
    const { statusCode, payload } = boomified.output;

    res.status(statusCode);
    res.json(payload);

    return;
  }

  await fn(req, res);
};

export default new Proxy(withMethod, {
  get: (target, handler) => target(handler),
});

then you can use withMethod like this

const HealthCheck = (_, res) => {
  res.status(200).send('OK');
};

export default withMethod.GET(HealthCheck);

[stramel]

Thanks for the very nice code snippet @KieraDOG! I like that setup for a user-land solution, however, how would that implement multiple methods for a single endpoint like GET, POST, PUT for /api/users?

[KieraDOG]

We dont have a use case for PUT and POST on same resource, so

• GET: /pages/api/users/[id].js
• POST: /pages/api/users

[stramel]

Ah, I was just throwing out a random example, sorry. I was looking for handling multiple methods like fetching a list of users (GET /users) and adding a new user (POST /users) on a single api file.

[loteoo]

I found this tiny helper library to help with this, which works super great with API routes:
https://github.com/jamo/micro-method-router

module.exports = methods({
  get: async (req, res) => {
    return res.status(200).end('It's a GET request!');
  },
  post: async (req, res) => {
    return res.status(200).end('It's a POST request!');
  }
})

Works well with middlewares too!

module.exports = someMiddlewareForAllMethods(methods({
  get: async (req, res) => {
    return res.status(200).end('It's a GET request!');
  },
  post: someMiddleWareJustForPostMethod(async (req, res) => {
    return res.status(200).end('It's a POST request!');
  })
}))

But I still think it would be great if Next.js did this out-of-the-box by checking the get, post, etc exports from the modules.