server.js

const { ApolloServer, gql } = require('apollo-server');

const { validateToken } = require("./authService");
const resolvers = require("./resolvers");

const typeDefs = gql`
  type User {
    id: ID!
    email: String!
    password: String!
  }
  type Post {
    title: String!
    authorId: ID!
  }
  type AuthResponse {
    token: String!
  }
  type Query {
    posts: [Post!]!
  }
  type Mutation {
    login(email: String!, password: String!): AuthResponse!
  }
`;

const context = ({ req }) => {
  if (req.body.query.match("Login")) return {};

  const authorizationHeader = req.headers.authorization || '';
  const token = authorizationHeader.split(' ')[1];

  if (!token) throw new Error("Authentication token is required.");

  const user = validateToken(token);

  return { user };
}

const server = new ApolloServer({
  typeDefs,
  resolvers,
  context,
  playground: false
});

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