express+apollo+mongodb

阿波罗服务器入门

λ yarn add --dev @babel/core @babel/cli @babel/preset-env
λ yarn add --dev nodemon  // "start": "nodemon --exec babel-node index.js"
λ yarn add apollo-server graphql express

http://localhost:4000/?query={hello}

const { gql, ApolloServer } = require("apollo-server");
const _ = require("lodash");
const cats = [{ id: 1, name: "a" }, { id: 2, name: "b" }, { id: 3, name: "c" }];
const l = console.log;
const typeDefs = gql`
  type Query {
    cats: [Cat]
    findCat(id: ID!): Cat
  }

  type Mutation {
    addCat(cat: InputCat): Cat
    changeCat(id: ID!, name: String): Cat
  }

  input InputCat {
    name: String
  }

  type Cat {
    id: String
    name: String
  }
`;

const resolvers = {
  Query: {
    cats: (parent, args, context, info) => {
      return cats;
    },

    findCat(parent, args, context, info) {
      const { id } = args;
      return _.find(cats, { id: +id });
    },
  },
  Mutation: {
    addCat(parent, args, context, info) {
      const { cat } = args;
      cats.push({
        ...cat,
        id: _.size(cats),
      });
      return _.last(cats);
    },
    changeCat(parent, args, context, info) {
      l(args);
      const { id, name } = args;
      cats[_.findIndex(cats, ["id", +id])].name = name;
      return _.find(cats, ["id", +id]);
    },
  },
};

const server = new ApolloServer({
  typeDefs,
  resolvers,
});

server.listen().then(({ url }) => {
  console.log(` Server ready at ${url}`);
});

get: http://localhost:4000/?query={cats { id name }}
get: http://localhost:4000/?query={ findCat(id: 1) { name } }