Currently, I am working on a node.js application that includes a registration function. Within this function, the challenge lies in verifying whether a username has already been taken or not. My issue arises from the fact that the SQL module in node only accepts a callback function, making it impossible to return any booleans directly.
Below is an excerpt of the code from my controller module:
async function createUser(req, res) {
try {
const salt = await bcrypt.genSalt();
const hashedPassword = await bcrypt.hash(req.body.password, salt);
const newUser = {
userName: req.body.username,
userPassword: hashedPassword
};
const userExists = model.checkIfUserExists(newUser.userName);
if (userExists == false){
// create new user
} else {
// Send json back "user already exists"
}
res.status(201).json(newUser);
} catch {
res.status(500);
}
}
And here is the snippet of code from the model:
function checkIfUserExists(Username){
console.log("Checking if user exists");
let sql = "SELECT * FROM users WHERE user_name = ?";
db_conn.query(sql, Username, (err, result) => {
if (err){
throw err;
}
console.log(result);
if (result.length > 0){
return true;
} else {
return false;
}
});
}
Unfortunately, the "checkIfUserExists" method does not provide a direct true or false value, resulting in the "userExists" variable being null.
I am seeking advice on how to overcome this issue and improve the elegance of the code. Any assistance in fixing this would be greatly appreciated. Thank you :)