How to use properly promises in node.js project using classes? - node.js

Question

(solution at the bottom)Project construction
I am converting a 'simple' node.js project into full object project node.js. I have found ressources to better organize my files but i still have a problem with classes. I have done php project in object, but the node JS structure seems to be particular.
I consulted :
Node Modular Architecture
How to correctly modularize a node.js project?
For what I understand :
app.js is my router from where I will define what controller I need to respond to the client request.
/routes is where I have my controllers where I instantiate my objects and use their methods.
project organization
My classes are in a folder at the root but I could move it to the public/javascript folder. My problem is about to confine application tier code in the classes that are supposed to access the database.
For exemple, only the class User has a method to update the user name in the database. So in my controlers (/routes) I dont want any sql queries (using sequelize by the way).
I don't know how to do
I tried to do a promise in the controller in which I call the class's method who does the query and return the result.
var user = new User();
var users = new Promise(function(resolve, reject) {
user.select();
});
Promise.all([users]).then(function(values){
console.log(values);
}
console.log(users);
)
In my class I do
models.user.findAll({
attributes: ['user_login','user_points','user_id']
}).then(
users => {
resolve(users);
}
)
Here as expected, resolve is not define. But if I put the resolve just after I call the class method like this:
var users = new Promise(function(resolve, reject) {
user.select();
resolve(result);
});
result is not defined and it will resolve without waiting for the query to be done.
Questions
As I am not experimented and dont find any detailed or recent topic on this subject I don't have any clue on how to proceed.
My first question is : does the problem could come from files organization (or more generaly is mine a usual/good practice).
My second question is how do I handle this type of structure with classes and node.js so my exemple should work.
Thank you for your help.
I will add that since I dont find recent topic on this subject I am verry interested in making a step by step guide to build a full object project in node.js with app/routes/classes and ES6 js. The objective is to better understand it and give it to my supervisor so he can correct it and use it for future recruits and publish it.
Solution
Thanks to #estus, I now unerstand that you can store a Promise in a variable.
It allow me to use a .then on this variable.
var result = a.select();
result.then(function(result) {
console.log('my result : ', result);
});
In the class you only return the result as you dont want to resolve the Sequelize promise :
users => {
return users;
}