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

🧘 Fully-featured GraphQL Server with focus on easy setup, performance & extensibility

Install

Simply install graphql-yoga via NPM/Yarn

yarn add graphql-yoga

Usage

Quickstart (Hosted demo)

import { GraphQLServer } from './graphql-yoga'

const typeDefs = `
  type Query {
    hello(name: String): String!
  }
`

const resolvers = {
  Query: {
    hello: (_, { name }) => `Hello ${name || 'World'}`,
  },
}

const server = new GraphQLServer({ typeDefs, resolvers })
server.start(3000, () => console.log('Server is running on localhost:3000'))

Full example

import { GraphQLServer, PubSub } from './graphql-yoga'

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

  type SubResult {
    count: Int!
    other: String
  }

  type Subscription {
    counter: SubResult!
  }
`

const resolvers = {
  Query: {
    hello: () => 'Hello world',
  },
  SubResult: {
    other: () => 'Hello Counter',
  },
  Subscription: {
    counter: {
      subscribe: (parent, args, { pubsub }) => {
        const channel = 'x'
        let i = 0
        setInterval(() => pubsub.publish(channel, { counter: { count: i++ } }), 2000)
        return pubsub.asyncIterator(channel)
      },
    }
  },
}

const pubsub = new PubSub()
const server = new GraphQLServer({ typeDefs, resolvers, context: { pubsub } })

server.start(3000, () => console.log('Server is running on localhost:3000'))