NodeJS - how to break a function?

Recently had a similar question, but still can't get it. I have to validate registration page before adding new user.

app.post('/signup', function(req, res) {
    //checking if first name is filled
    if (req.body.first_name = "" || req.body.first_name = null || req.body.first_name = undefined) {
      res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "error" : "empty_first_name" });
      break;
    }
    //checking if last name is filled
    if (req.body.last_name = "" || req.body.last_name = null || req.body.last_name = undefined) {
      res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "error" : "empty_last_name" });
      break;
    }
    //checking if email is filled
    if (req.body.email = "" || req.body.email = null || req.body.email = undefined) {
      res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "error" : "empty_email" });
      break;
    }
    //checking if passwords match
    if (req.body.password != req.body.repassword) {
      res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "error" : "pass_missmatch" });
      break;
    }
    ...
    ...
    ...
    //and finally if everything seems to be OK...
    addUser(req.body.email, req.body.password, req.body.first_name, req.body.last_name, req.body.country, function(status) {
        res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "success" : 1 });
    });
});

Node.JS tells me that all the breaks are illegial. But how should I break my function in a proper way? It doesn't return anything. Thanks!

A return statement is used to halt a function.

You can provide an optional return value, but in this case, I believe it would be ignored, so you should just be able to replace break; with return;.


Side note, but you have a good bit of repeating code, and you have assignments in your if conditions. You can usually factor away the repetition. Also, you can get rid of the return altogether if you use if/else if/else statements.

Here's an example.

function isEmpty(val) {
    return val === "" || val == null;
}

function renderWithError(req, res, msg) {
    res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "error" : msg });
}

app.post('/signup', function(req, res) {
    if (isEmpty(req.body.first_name)) {
      renderWithError(req, res, "empty_first_name");
    }
    else if (isEmpty(req.body.last_name)) {
      renderWithError(req, res, "empty_last_name");
    }
    else if (isEmpty(req.body.email)) {
      renderWithError(req, res, "empty_email");
    }
    else if (req.body.password != req.body.repassword) {
      renderWithError(req, res, "pass_missmatch");
    }
    ...
    ...
    ...
    else {
        addUser(req.body.email, req.body.password, req.body.first_name, req.body.last_name, req.body.country, function(status) {
            res.render('signup', { "title": "Ttitle", "menu": "signup", user: req.user, "success" : 1 });
        });
    }
});