myrotvorets / express-acceptsjson-middleware

Express.js middleware to check whether the client is willing to accept JSON response

express-acceptsjson-middleware

Express.js middleware to check whether the client is willing to accept JSON response.

Usage

import { type Request, type Response, Router } from 'express';
import { acceptsJsonMiddleware } from '@myrotvorets/express-acceptsjson-middleware';

const router = Router();
router.get('/some-path', acceptsJsonMiddleware, otherHandler);

What it Does

The middleware checks the presence of Accept HTTP header, and if it is there, it checks whther the client is willing to accept JSON. If not, it returns 406 Not Acceptable error (with JSON payload :-) ).

It is considered that the client is willing to accept JSON if at least one of the following conditions is true:

• there is no Accept header;
• Accept header contains */* or */json;
• Accept header contains application/* or application/json.

The actual check is performed by Request.accepts().