How can I use type-graphql and RESTDataSource - typegraphql

Question

I wonder how it is possible to use RESTDataSource in type-graphql and thus cache correctly in a redis. I would be grateful for a small example.
At the moment I use the DI container to get a service, which is extended from the RestDataSource class, but this is not the right way.
BookmarkResolver.ts
import { Resolver, FieldResolver, Root, Query, Ctx, Authorized } from 'type-graphql';
import { DealService } from '../service/DealService';
import { AvailableLocale } from '../enum/AvailableLocale';
import { Bookmark } from '../entity/Bookmark';
#Resolver(_of => Bookmark)
export class BookmarkResolver {
constructor(private dealService: DealService) {}
#FieldResolver()
async wordpressDeal(#Root() bookmark: Bookmark) {
return await this.dealService.getDealById(bookmark.item_id, AvailableLocale.STAGING);
}
}
DealService.ts
import { Service } from 'typedi';
import { AbstractService } from './AbstractService';
import { AvailableLocale } from '../enum/AvailableLocale';
#Service()
export class DealService extends AbstractService {
baseURL = process.env.DEAL_SERVICE_URL;
async getDealById(dealId: string | number, locale: AvailableLocale) {
const response = await this.get(
'deals/' + dealId,
{ locale }
);
return this.dealReducer(response);
}
dealReducer(deal: any) {
return {
id: deal.id || 0,
title: deal.title
};
}
}
AbstractService.ts
import { RESTDataSource, HTTPCache } from 'apollo-datasource-rest';
import { Service } from 'typedi';
#Service()
export class AbstractService extends RESTDataSource {
constructor() {
super();
this.httpCache = new HTTPCache();
}
}

Answer 1

Share the RESTDataSource via ApolloServer's context. Use it in the resolver by accessing the context with the #Ctx() decorator.
1. Define a RESTDataSource
Define the data source according to the apollo-datasource-rest example.
export class TodoDataSource extends RESTDataSource {
constructor() {
super();
this.baseURL = "https://jsonplaceholder.typicode.com/todos";
}
async getTodos(): Promise<Todo[]> {
return this.get("/");
}
}
2. Create an instance of the DataSource and put it in the Context
When you start the server, add data sources to the context by defining a function that creates the data sources.
const server = new ApolloServer({
schema,
playground: true,
dataSources: () => ({
todoDataSource: new TodoDataSource(),
}),
});
3. Access the DataSource in the resolver
Use the #Ctx() decorator to access the context in the resolver so you can use the data source.
#Resolver(Todo)
export class TodoResolver {
#Query(() => [Todo])
async todos(#Ctx() context: Context) {
return context.dataSources.todoDataSource.getTodos();
}
}
Full, runnable example at https://github.com/lauriharpf/type-graphql-restdatasource