server.js

const { ApolloServer} = require('apollo-server')
const mongoose = require("mongoose")
require("dotenv").config();

const typeDefs = require("./typeDefs")
const resolvers = require("./resolvers")
const {findOrCreateUser} = require('./controllers/userController')

mongoose
    .connect(process.env.MONGO_URI, {useNewUrlParser: true })
    .then(() => console.log("DB connected!"))
    .catch(err => console.error(err))

const server = new ApolloServer({
    typeDefs,
    resolvers,
    context: async ({req}) => {
        let authToken = null
        let currentUser = null
        try{
            authToken = req.headers.authorization
            if (authToken) {
               currentUser = await findOrCreateUser(authToken)
            }
        }
        catch (err){
            console.error(`Unable to authenticate user with token ${authToken}`)
        }
        return { currentUser }
    }
})

server.listen({ port: process.env.PORT || 4000}).then(({ url }) =>{
    console.log(`Server listening on ${url}`)
})