Router doesn't get response from database functions - node.js

Question

when running the app and testing the /signup route the data gets written to the db and i can console.log it from the database/models.js file, but in the routes/index.js file it returns "Something went wrong." and postman shows nothing, not even an empty array or object.
routes/index.js
var express = require('express');
var router = express.Router();
const database = require('../database/models');
router.post('/signup', function(req, res, next) {
if (!req.body.email || !isValidEmail(req.body.email))
res.status(400).send('Email invalid.');
else if (!req.body.username || !isValidCredential(req.body.username) || !req.body.password || !isValidCredential(req.body.password))
res.status(400).send('Username/password invalid.');
else {
const result = database.createUser(req.body.email, req.body.username, req.body.password);
if (result)
res.status(200).send(result);
else
res.send('Something went wrong.');
}
});
function isValidEmail (email) {
if (email.match("[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*#(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?"))
return true;
else
return false;
}
function isValidCredential (credential) {
if (credential.length < 6)
return false;
else if (credential.match(/^[a-z0-9]+$/i))
return true;
else
return false;
}
module.exports = router;
database/models.js
const tools = require('./tools');
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const userSchema = new Schema({
email: String,
username: String,
hashedPassword: String,
salt: String,
accessToken: { type: String, default: "" }
});
const User = mongoose.model('User', userSchema);
function createUser(email, username, password) {
const hashPass = tools.generatePassword(password);
const newUser = new User({
email: email,
username: username,
hashedPassword: hashPass.hash,
salt: hashPass.salt
});
newUser.save(function (error, result) {
if (error)
return handleError(error);
return { email: result.email, username: result.username };
});
}
module.exports.createUser = createUser;

Answer 1

In your code you are not returning anything when calling the createUser function. Here a couple of considerations:
// index.js
const result = database.createUser(req.body.email, req.body.username, req.body.password);
since the createUser is an operation performed on a database, it will be probably asynchronous, and therefore also its result. I suggest the usage of async/await to be sure of the returned result. Also, you need to change the code of your models.js file to return a Promise and await for it.
function createUser(email, username, password) {
const hashPass = tools.generatePassword(password);
const newUser = new User({
email: email,
username: username,
hashedPassword: hashPass.hash,
salt: hashPass.salt
});
return new Promise((resolve, reject)=> {
newUser.save(function (error, result) {
if (error) reject(error);
resolve({ email: result.email, username: result.username });
});
});
}
and than you will have to await for your result. You can do it in the following way:
// index.js
// Add async here
router.post('/signup', async function(req, res, next) {
// ...other code
// Add await here
const result = await database.createUser(req.body.email, req.body.username, req.body.password);

Answer 2

I figured it out.
in routes/index.js use async/await like this:
router.post('/signup', async function(req, res, next) {
try {
if (!req.body.email || !isValidEmail(req.body.email))
res.status(400).send('Email invalid.');
else if (!req.body.username || !isValidCredential(req.body.username) || !req.body.password || !isValidCredential(req.body.password))
res.status(400).send('Username/password invalid.');
else {
const result = await database.createUser(req.body.email, req.body.username, req.body.password);
if (result)
res.status(200).send(result);
else
res.status(403).send(result);
}
} catch (error) { return error; }
});
and in database/models.js use async/await as well, but also rewrite mongoose methods into ones without callbacks, with returns into variables, like this:
async function createUser(email, username, password) {
try {
const hashPass = tools.generatePassword(password);
const newUser = new User({
email: email,
username: username,
hashedPassword: hashPass.hash,
salt: hashPass.salt
});
const result = await newUser.save();
return { email: result.email, username: result.username };
} catch (error) { console.log (error); return error; }
}