graphql-server.js

const { makeExecutableSchema } = require('graphql-tools');

const typeDefs = [`
type Query {
  hello: String
}

schema {
  query: Query
}`];

var resolvers = {
  Query: {
    hello(root) {
      return 'world';
    }
  }
};

const schema = makeExecutableSchema({typeDefs, resolvers});