graphql-yoga

What is graphql-yoga?

graphql-yoga is a fully-featured GraphQL server that is easy to set up and use. It is built on top of GraphQL.js and provides a simple yet powerful API for building GraphQL servers. It comes with out-of-the-box support for features like subscriptions, file uploads, and more.

What are graphql-yoga's main functionalities?

Basic Server Setup

This code sets up a basic GraphQL server with a single query 'hello' that returns a string. The server is started and listens on port 4000.

const { createServer } = require('graphql-yoga');
const typeDefs = `
  type Query {
    hello: String!
  }
`;
const resolvers = {
  Query: {
    hello: () => 'Hello, world!',
  },
};
const server = createServer({ typeDefs, resolvers });
server.start(() => console.log('Server is running on http://localhost:4000'));

Subscriptions

This code demonstrates how to set up a GraphQL server with subscriptions. It uses the 'graphql-subscriptions' package to handle real-time updates. A new message is published every second.

const { createServer } = require('graphql-yoga');
const { PubSub } = require('graphql-subscriptions');
const pubsub = new PubSub();
const typeDefs = `
  type Query {
    hello: String!
  }
  type Subscription {
    newMessage: String!
  }
`;
const resolvers = {
  Query: {
    hello: () => 'Hello, world!',
  },
  Subscription: {
    newMessage: {
      subscribe: () => pubsub.asyncIterator(['NEW_MESSAGE']),
    },
  },
};
const server = createServer({ typeDefs, resolvers });
server.start(() => console.log('Server is running on http://localhost:4000'));
setInterval(() => {
  pubsub.publish('NEW_MESSAGE', { newMessage: 'Hello, world!' });
}, 1000);

File Uploads

This code sets up a GraphQL server that supports file uploads. It defines a custom scalar 'Upload' and a mutation 'singleUpload' that handles the file upload process.

const { createServer } = require('graphql-yoga');
const typeDefs = `
  scalar Upload
  type Query {
    hello: String!
  }
  type Mutation {
    singleUpload(file: Upload!): String!
  }
`;
const resolvers = {
  Query: {
    hello: () => 'Hello, world!',
  },
  Mutation: {
    singleUpload: async (parent, { file }) => {
      const { createReadStream, filename } = await file;
      createReadStream().pipe(fs.createWriteStream(path.join(__dirname, filename)));
      return filename;
    },
  },
};
const server = createServer({ typeDefs, resolvers });
server.start(() => console.log('Server is running on http://localhost:4000'));

Other packages similar to graphql-yoga

apollo-server

Apollo Server is a community-driven, open-source GraphQL server that works with any GraphQL schema. It provides a robust set of features, including caching, subscriptions, and more. Compared to graphql-yoga, Apollo Server offers more advanced features and integrations but may require more configuration.

express-graphql

express-graphql is a minimalistic GraphQL HTTP server middleware for Express. It is easy to set up and use, making it a good choice for simple applications. However, it lacks some of the advanced features provided by graphql-yoga, such as built-in subscriptions and file uploads.

graphql-koa

graphql-koa is a GraphQL server middleware for Koa. It provides a simple way to integrate GraphQL into a Koa application. While it is similar to express-graphql in terms of simplicity, it does not offer the same level of built-in features as graphql-yoga.

README

@graphql-yoga

const { GraphQLSchema, GraphQLObjectType, GraphQLString } = require('graphql')
const { GraphQLServer } = require('../core/dist')

const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'Query',
    fields: () => ({
      song: {
        type: new GraphQLObjectType({
          name: 'Song',
          fields: () => ({
            firstVerse: {
              type: GraphQLString,
              resolve: (_, __, { logger }) => {
                logger.info('I can even use the same logger!')
                return "Now I know my ABC's."
              },
            },
            secondVerse: {
              type: GraphQLString,
              resolve: () =>
                new Promise((resolve) =>
                  setTimeout(
                    () => resolve("Next time won't you sing with me?"),
                    5000,
                  ),
                ),
            },
          }),
        }),
        resolve: () => ({}),
      },
    }),
  }),
})

const server = new GraphQLServer({ schema })
server.start()