How to stop execution of a node.js script?

Question

Say I've got this script:

var thisIsTrue = false;

exports.test = function(request,response){

    if(thisIsTrue){
        response.send('All is good!');
    }else{
        response.send('ERROR! ERROR!');
        // Stop script execution here.
    }

    console.log('I do not want this to happen if there is an error.');

}

And as you can see, I'd like to stop the script from executing any downstream functions if there's an error.

I've managed to achieve this by adding return; after the error response is sent:

var thisIsTrue = false;

exports.test = function(request,response){

    if(thisIsTrue){
        response.send('All is good!');
    }else{
        response.send('ERROR! ERROR!');
        return;
    }

    console.log('I do not want this to happen if there is an error.');

}

But is that the 'correct' way to do things?

Alternatives

I've also seen examples that use process.exit(); and process.exit(1);, but that gives me a 502 Bad Gateway error (I assume because it kills node?).

And callback();, which just gave me an 'undefined' error.

What is the 'correct' way to stop a node.js script at any given point and prevent any downstream functions from executing?

Answer 1

Using a return is the correct way to stop a function executing. You are correct in that process.exit() would kill the whole node process, rather than just stopping that individual function. Even if you are using a callback function, you'd want to return it to stop the function execution.

ASIDE: The standard callback is a function where the first argument is an error, or null if there was no error, so if you were using a callback the above would look like:

var thisIsTrue = false;

exports.test = function(request, response, cb){

    if (thisIsTrue) {
        response.send('All is good!');
        cb(null, response)
    } else {
        response.send('ERROR! ERROR!');
        return cb("THIS ISN'T TRUE!");
    }

    console.log('I do not want this to happen. If there is an error.');

}