const Mutation = new GraphQLObjectType({
  name: 'Mutation',
  fields: {
    addGadget: {
      type: gadgetGraphQLType,
      args: {
        name: { type: GraphQLString },
        release_date: { type: GraphQLString },
        by_company: { type: GraphQLString },
        price: { type: GraphQLString }
      },
      resolve(parent, args) {
        const newGadget = new Gadget({
          name: args.name,
          release_date: args.release_date,
          by_company: args.by_company,
          price: args.price,
        })

        return newGadget.save();
      }
    }, // add new mutation
    updateGadget: {
      type: gadgetGraphQLType,
      args: {
        id: { type: GraphQLString },
        name: { type: GraphQLString },
        release_date: { type: GraphQLString },
        by_company: { type: GraphQLString },
        price: { type: GraphQLString }
      },
      resolve(parent, args) {

      }
    }
  }
})