Handling Promise rejection within Express routes

express-promise-rejection.js

'use strict';

const fetch = require('node-fetch');
const express = require('express');
const router = express.Router();

/* This function returns an inner function(i.e. a higher-order
 * function) that will be invoked by Express when a particular
 * path is request. This inner function will invoke the wrapped
 * handler, and invoke Express' next function if the returned 
 * Promise is rejected. */
function createPromiseRoute(route) {                                                         
    return (req, res, next) => route(req, res).catch(next);                                                   
}

function myRoute(req, res) {
    return fetch('https://some-api')
        .then(r => r.json())
        .then(r => res.json(r));
}

router.get('/data', createPromiseRoute(myRoute));

module.exports = router;