How to wait for an asynchronous function to complete?

Question

JavaScript

Hello there is a code:

var isLoginIn = false;

ajcom.register('login', (hCtx, email, pass) => {

     User.findOne({
        where: {
          email: email
        }
      }).then(function(foundUser) {
        if (foundUser && foundUser.password === pass) {
          console.log("Авторизация прошла успешно!");
          isLoginIn = tru;
        }
        else {
          console.log("Неверные данные, проверьте ваш email и пароль!");
        }
      });
      return {authorized: isLoginIn};
});

The problem is that I need to return {authorized: isLoginIn};return the data after the request to the database, if the authorization is successful, then isLoginIn = true;the fact is that the return {authorized: isLoginIn};request does not wait, how are these situations solved?

Answer 1

ajcom.register('login', async (hCtx, email, pass) => {
  const foundUser = await User.findOne({ where: { email } });
  
  if (foundUser && foundUser.password === pass) {
    console.log("Авторизация прошла успешно!");
    isLoginIn = true;
  } else {
    console.log("Неверные данные, проверьте ваш email и пароль!");
  }
  return { authorized: isLoginIn };
});

Answer 2

If you do not go into too much detail, then you can do this:

User.findOne({
        where: {
          email: email
        }
      }).then(function(foundUser) {
        if (foundUser && foundUser.password === pass) {
          console.log("Авторизация прошла успешно!");
          isLoginIn = tru;
        }
        else {
          console.log("Неверные данные, проверьте ваш email и пароль!");
        }
      }).then(function() { 
         return {authorized: isLoginIn};
      });

But you need to understand that the function is asynchronous and in any case you will have to wait for its execution. If promises look unclear, then look at async\await

Answer 3

async, await will easily solve your problem.