CODEWITHSUNDEEP
javascriptnode.jsexpress
marcfalk
marcfalk

Reputation: 31

Node + Express repeatedly firing/looping requests although result has been sent

I have tried almost everything, and my mind has now finally given up. Hence, I'm here asking for directions. How on earth can this simple piece of code (let's call it app.js):

var express = require('express');
var app = express();

app.use(function(req, res) {
  console.log('Request made')
  res.send('Hello World!');
});

app.listen(3000, function() {
  console.log('Example app listening on port 3000!');
});

When run like node app.js result in the following outcome in my terminal, considering the fact that I've only hit localhost:3000 once:

Example app listening on port 3000!
Request made
Request made
Request made
Request made
Request made
Request made
Request made
...continues...

For some reason I end up with "Request made" being repeated again and again although the request is done and delivered to the browser.

The same is true if I use app.get('*', function(req, res) { ... }) instead of app.use(function(req, res) { ... }).

If I turn to something more specific, like app.get('/', function(req, res) { ... }) the repetition stops and I get one "Request made" as expected. However, I need to match all incoming requests - in my app I'm doing something way more complicated than logging "Request made" :)

Any ideas? Thanks!

Node: 8.11.2 Express: 4.16.3

Upvotes: 1

Views: 527

Answers (1)

Zohaib Ijaz
Zohaib Ijaz

Reputation: 22875

You need to do something and then pass the results to next callback instead of sending a response which makes it recursive since it's intercepting a response and then doing the same causing a loop.

// this middleware will not allow the request to go beyond it
app.use(function(req, res, next) {
 res.send('Hello World');
});

// requests will never reach this route
app.get('/', function (req, res) {
  res.send('Welcome');
});

You need to call next() to invoke middleware

app.get('/', function (req, res, next) {
  try {
      // do something and return result
      res.send('Welcome');
  } catch(e) {
      next(e)
  }

});

app.use(function (err, req, res, next) {
  console.log('Error occurred')
  res.status(err.statusCode).send(err.message);
});

Upvotes: 1

Related Questions