Automatically include referenced model in Sequelize on each GET - node.js

Question

So I have user model and admin model and they're associated as user n:1 admin. The code defining the user model as follows:
// users.model.ts
const users = sequelize.define('users', {
...
adminId: {
field: 'admin_id',
type: DataTypes.BIGINT,
allowNull: true
},
...
});
(users as any).associate = function associate(models: any) {
models.users.belongsTo(models.admins);
};
return users;
and the admin model:
// admins.model.ts
const admins = sequelizeClient.define('admins', {
...
});
(admins as any).associate = function associate(models: any) {
models.admins.hasOne(models.users);
};
return admins;
Is it possible to implement some rule in the association, or some Sequelize hook f.e. afterGet that will automatically fetch the referenced record?
I would like to get the admin object as a property of the user object when I query just the User model, f.e. when I call User.findOne(123) it will have the object of the referenced admin record included. Basically telling Sequelize to always do the JOIN when getting the user record. Is that possible in Sequelize or I'll have to write logic separately?

Answer 1

Eventually I figured out that this is done through scopes (docs here and here).
I added this to the users.model.ts:
/*
* When called as `model.scope('<scope_name>').<method>` it will override the default behaviour of Sequelize and
* will add to the query whatever is requested in the scope definition.
*/
users.addScope('includeAdmin', {
include: [{
attributes: ['id', 'name'],
model: sequelize.models.admins,
as: 'admin'
}]
});
Eventually, I will make the following call: User.scope('includeAdmin').findOne(123), at which point Sequelize will automatically JOIN the admins model.
By default the admin entity's properties will be returned as such in the user object:
{
"admin.id": ...,
"admin.name": ...
}
So, if you want to have them as a nested admin object, then you must add nest: true property in the call, as follows: User.scope('includeAdmin').findOne(123, {nest: true})
If I want to make this behaviour default and not call .scope('...'), then when you declare the scope in the .addScope() function, call it 'defaultScope'.

Answer 2

That's why associations are used, to get things. To get the relation as attribute you can use eager loading:
const awesomeCaptain = await Captain.findOne({
where: {
name: "Jack Sparrow"
},
include: Ship
});
// Now the ship comes with it
console.log('Name:', awesomeCaptain.name);
console.log('Skill Level:', awesomeCaptain.skillLevel);
console.log('Ship Name:', awesomeCaptain.ship.name);
console.log('Amount of Sails:', awesomeCaptain.ship.amountOfSails);