How to use Node.js in Postgraphile mutations? - node.js

Question

I am making an application that shows information about different users, which is taken from third party API. I save this information in my own format with multiple tables in PostgreSQL to keep track of any changes to the data and provide history of changes (third party API only provides current data).
I want to use GraphQL, specifically Postgraphile to simplify backend development. But there is one use case which I can't find a way to implement with Postgraphile. Here is what I want to implement:
User wants to see an updated information
GraphQL mutation query is sent to the server, something like this:
mutation UpdateUserData($userid: Int) {
updateUser(id: $userid) {
field1,
field2,
relatedObjects {
field3,
filed3
}
}
}
Server makes an API request to third party server, processes data, makes some calculations and updates the database
Requested fields are returned to client
I know that this type of custom mutations can be implemented with database functions like PL/pgSQL or PLV8, but they can't make http requests and I already have most of the logic for data processing in Typescript, so would like to use it.
Is there a way to create a custom mutation that will call JavaScript function which has access to Node.js modules, interfaces and classes that I already created?
One solution that I think will work:
Call REST endpoint on my server, like /update_user?id=$userid
User data is loaded from third party API and database is updated
Client receives response, like Update successful
Normal GraphQL query is called to get the data
Is there a better way of satisfying this use case?

Answer 1

This part is a bit hidden in the documentation, but the easiest way to add mutations written in JavaScript is the makeExtendSchemaPlugin.
Here you can define type definitions in SDL and implement resolvers in JS.