Mongoose promises and async - await (and before that it just returned emptiness), but now why does the promise return?

Question

JavaScript

async finduser(id) {
    const us = await UserScheme.findOne({ id });
    console.log('fck'); -- кстати это не отображает в консоли
    return us;
  }

checkAddUser(user) {
    console.log('us .');
    const ff = this.finduser(user.id);

    const res = ff.length ? ff[0].id : undefined;
    console.log('u3s .' + ff);
    if (res === undefined) {
      console.log(`${user.id} add new user`);
      this.adduser(user.id, user.first_name, user.last_name, user.username);
      return false;
    }
    if (ff[0].city != null) {
      return ff;
    }

    console.log(`${user.id} authorized`);
    return ff;
  }

How else to catch all sorts of errors and so on. competently here in the code (I read Google, but it didn’t fit this situation (when the function returned emptiness at all, + some console logs didn’t work after it))

I’ll still use moleculer. Can its means handle errors and other easier?
By the way, what does findOne return if it doesn't find findOne?

Answer 1

an async function returns a Promise, so you don't have a string in ff.
To get a row, you need to use await when calling this.finduser, for which you declare checkAddUser as async.

Answer 2

if anything, then I solved the problem, my Eslint + prettier ate an unused object during autosave. and this object initialized the connection to the database
True, xs, why the hell * didn’t write a single hint .....