Postprocess Sequelize finders with Express - node.js

Question

I am new to Javascript.
I am developping an API to retrieve information from MySQL with :
Node.js
Express
Sequelize
I developed the following controller based on a Sequelize finder (findByPk, to retrieve information by a primary key). There are several nested includes.
exports.findByPk = (req, res) => {
Poi.findByPk(req.params.id,{
attributes: [
'name',
'description'
],
include: [{
model: Source,
attributes: ['originalId'],
where: {source: 'google'}
},{
...
}]
})
.then(data => {
res.send(data);
})
};
As far as I understand, the finder outputs a relatively complex Sequelize instance object data which is passed in res.send (but the API gives access to a proper Json).
I need to postprocess data before passing the result in res.send :
I need to retreive information from a Google API using the data fields, and add this information to the API output
I need to compute some values based on the data fields, and add these values to the API output (long story short, it cannot be part of the Sequelize query because of a known issue in Sequelize)
How to retrieve the values I need from data ? Should I treat it as a regular javascript object, understand its structure, and manually retrieve the values I need ? Or are there methods for that ?
After that, how to add information to data ? Should I actually add information to data, or create a new object ? Should it be a Sequelize object or can it be a regular json-like javascript object ?
Thank you very much

Answer 1

You can just turn data (that is actually an instance of the Poi Sequelize model) into a plain JS object and afterwards work with it in a regular way:
.then(data => {
const plainObject = data.get({ plain: true });
plainObject.newProp = 1
// some work here including accessing Google API
...
res.json(plainObject);