text: const { gql } = require('apollo-server');
  
  const typeDefs = gql`
      # schema goes here, written in schema definition language (SDL).
        
        type Launch {
          id: ID!
          site: String
          mission: Mission
          rocket: Rocket
          isBooked: Boolean!
        }
  
        type Rocket {
          id: ID!
          name: String
          type: String
        }
        
        type User {
          id: ID!
          email: String!
          trips: [Launch]!
        }
        
        type Mission {
          name: String
          missionPatch(size: PatchSize): String
        }
        
        enum PatchSize {
          SMALL
          LARGE
        }
  
        type Query {
          launches: [Launch]! # array of all launches.
          launch(id: ID!): Launch # a single launch given from an id.
          me: User # provides details of a user.
        }
  
        type Mutation {
          bookTrips(launchIds: [ID]!): TripUpdateResponse!
          cancelTrip(launchId: ID!): TripUpdateResponse!
          login(email: String): String # login token
        }
  
        type TripUpdateResponse {
          success: Boolean!
          message: String
          launches: [Launch]
        }
      `;
  
  module.exports = typeDefs; 