server.js

/**
 * The Apollo Server which powers the backend
 * @namespace Apollo
 */
const { ApolloServer, ApolloError} = require('apollo-server');
const UserAPI = require('./users/user.datasources.js');
const ClubAPI = require('./clubs/club.datasources.js');
const EventAPI = require('./events/event.datasources.js');
const VenueAPI = require('./venues/venue.datasources.js');
const AccessLevelAPI = require('./accessLevels/accessLevel.datasources.js');
const StoryAPI = require('./stories/story.datasources.js');
const typeDefs = require('./schema.js');
const resolvers = require('./resolvers.js');
const {firebaseApp}=require("../helpers/firebase");
const { populatePermissions } = require("../helpers/permissions");

const NodeCache = require( "node-cache" );
const tokenCache = new NodeCache();


//Datasources
const dataSources = () => ({
	UserAPI: new UserAPI(),
	ClubAPI: new ClubAPI(),
	EventAPI: new EventAPI(),
	VenueAPI: new VenueAPI(),
	AccessLevelAPI: new AccessLevelAPI(),
	StoryAPI:new StoryAPI()
});

const server = new ApolloServer({
	typeDefs,
	resolvers,
	dataSources,
	introspection: true,
	resolverValidationOptions: { requireResolversForResolveType: false },
	playground: true,
	debug: false,
	/**
	 * GraphQL Context:  A top level function which decodes and verifies the JWT sent through the request header
	 *  @param {string} decodedToken - JWT token from request
	 * If the user is just signin up, they would be given permissions only to access the Auth Mutation
	 */
	context: async ({ req }) => {
		if (req.headers && req.headers.authorization) {
		    const idToken=req.headers.authorization;
			try {
				console.time("firebase");

				let userToken = tokenCache.get(idToken);
				if (userToken === undefined) {
					const decodedToken = await firebaseApp.auth().verifyIdToken(idToken)
					// eslint-disable-next-line prefer-destructuring
					userToken={ uid: decodedToken.uid, mongoID: decodedToken.mongoID }
					tokenCache.set(idToken, userToken,36000);
				}			

				console.timeEnd("firebase");
				
				if(userToken.mongoID){
					return {uid: userToken.uid, permissions: await populatePermissions(userToken.mongoID)};
				}
				return {uid: userToken.uid, permissions: ["users.Auth"]};				
				
		    } catch (error) {
				const errorMessage= error.errorInfo? error.errorInfo.message : error;
				return {
					error:{message: errorMessage,code: "UNAUTHORIZED"}
				}
		    }
		}else{
			return	{
				error:{message: "JWT not set",code: "UNAUTHENTICATED"}
			};
		}
	},
	formatError: err => new ApolloError(err.message,err.extensions.code)
});

module.exports = server;