how to return new record from graphql mutation instead of null

Question

I read through the apollo-server-tutorial and I'm trying to replicate it with only mongodb - no sqllite. I'm coming from meteor so I'm learning async & mongoose while I'm at it.

My mutation for addAuthor() works correctly (I see a new record in the DB) but graphiql returns null. How do I get it to return the expected fields?

mutation {
  addAuthor(firstName: "falieson", lastName:"p") {
    _id
    firstName
    lastName
  }
}

{
  "data": {
    "addAuthor": null
  }
}

Schema: https://github.com/Falieson/apollo-server-tutorial-only-mongodb/blob/master/data/schema.js#L39

Resolver: https://github.com/Falieson/apollo-server-tutorial-only-mongodb/blob/master/data/resolvers.js#L38

Mongoose: https://github.com/Falieson/apollo-server-tutorial-only-mongodb/blob/master/data/models/mongoose.js#L51

Model: https://github.com/Falieson/apollo-server-tutorial-only-mongodb/blob/master/data/models/index.js#L7

Answer 1

I needed to have mongoose return a promise for the mutation. So my MongooseModel.create() changes from

const record = new this.collection(args)
return record.save(cb)

to using Promise

const record = new this.collection(args)
return new Promise((resolve, reject) => {
   record.save((err, res) => {
      err ? reject(err): resolve(res)
   });
});

to using Async/Await

 async create(obj = {}) {
   const args = {
     ...this.defaultRecord(),
     ...obj
   }
   const record = new this.Collection(args)

   try {
     const savedRecord = await record.save()
     return savedRecord
   } catch (err) {
     handleError(err)
   }
 }

My mutation doesn't have to change at all, but my fixtures generator also has to be updated to use the Promise.then() chain.