NodeJS, Is it a bad practise to return res.json

Question

I\'m building a ExpressJS application with NodeJS. My question is there any performance difference if I do

app.get(\'/test\', function(req, res) {
    fn(functi         


        

Answer 1

On your exemple, based on callback function, there is no difference. But what if app.get return a Promise ?

This code will provide an Unhandled rejection Error

app.get('/test')
.then( (data) => 
{ /* do something with your data that can throw a functional error 
for exemple request for a user on your database based on your data */ 
  if (!user) res.json(401, {msg: 'USER NOT FOUND'});
  if (user.someProperty) //will throw an error when user is not found
   res.json(200, {msg: 'USER DID IT'});
})
.catch( (err) => {
  res.json(500, {msg: 'OUTCH'});
  throw(err);
});

This code will not

app.get('/test')
.then( (data) => 
{ /* do something with your data that can throw a functional error 
for exemple request for a user on your database based on your data */ 
  if (!user) return res.json(401, {msg: 'USER NOT FOUND'});
  if (user.someProperty) //will not be evaluate when user is not found
   return res.json(200, {msg: 'USER DID IT'});
})
.catch( (err) => {
  res.json(500, {msg: 'OUTCH'});
  throw(err);
});

When using promise always return ;)