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graphql-ws

授权协议 MIT License

开发语言 Java

所属分类大数据、数据查询

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软件概览

Coherent, zero-dependency, lazy, simple, GraphQL over WebSocket Protocol compliant server and client.

Use Server-sent events (SSE) instead? Check out graphql-sse!

Getting started

Install

yarn add graphql-ws

Create a GraphQL schema

import { buildSchema } from 'graphql';

// Construct a schema, using GraphQL schema language
const schema = buildSchema(`
  type Query {
    hello: String
  }
  type Subscription {
    greetings: String
  }
`);

// The roots provide resolvers for each GraphQL operation
const roots = {
  query: {
    hello: () => 'Hello World!',
  },
  subscription: {
    greetings: async function* sayHiIn5Languages() {
      for (const hi of ['Hi', 'Bonjour', 'Hola', 'Ciao', 'Zdravo']) {
        yield { greetings: hi };
      }
    },
  },
};

Start the server

With ws

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';

const server = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  // from the previous step
  { schema, roots },
  server,
);

console.log('Listening to port 4000');

With uWebSockets.js

import uWS from 'uWebSockets.js'; // yarn add uWebSockets.js@uNetworking/uWebSockets.js#<tag>
import { makeBehavior } from 'graphql-ws/lib/use/uWebSockets';

uWS
  .App()
  .ws(
    '/graphql',
    makeBehavior(
      // from the previous step
      { schema, roots },
    ),
  )
  .listen(4000, (listenSocket) => {
    if (listenSocket) {
      console.log('Listening to port 4000');
    }
  });

With fastify-websocket

import Fastify from 'fastify'; // yarn add fastify
import fastifyWebsocket from 'fastify-websocket'; // yarn add fastify-websocket
import { makeHandler } from 'graphql-ws/lib/use/fastify-websocket';

const fastify = Fastify();
fastify.register(fastifyWebsocket);

fastify.get(
  '/graphql',
  { websocket: true },
  makeHandler(
    // from the previous step
    { schema, roots },
  ),
);

fastify.listen(4000, (err) => {
  if (err) {
    fastify.log.error(err);
    return process.exit(1);
  }
  console.log('Listening to port 4000');
});

Use the client

import { createClient } from 'graphql-ws';

const client = createClient({
  url: 'ws://localhost:4000/graphql',
});

// query
(async () => {
  const result = await new Promise((resolve, reject) => {
    let result;
    client.subscribe(
      {
        query: '{ hello }',
      },
      {
        next: (data) => (result = data),
        error: reject,
        complete: () => resolve(result),
      },
    );
  });

  expect(result).toEqual({ hello: 'Hello World!' });
})();

// subscription
(async () => {
  const onNext = () => {
    /* handle incoming values */
  };

  let unsubscribe = () => {
    /* complete the subscription */
  };

  await new Promise((resolve, reject) => {
    unsubscribe = client.subscribe(
      {
        query: 'subscription { greetings }',
      },
      {
        next: onNext,
        error: reject,
        complete: resolve,
      },
    );
  });

  expect(onNext).toBeCalledTimes(5); // we say "Hi" in 5 languages
})();

Recipes

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Client usage with Promise

import { createClient, SubscribePayload } from 'graphql-ws';

const client = createClient({
  url: 'ws://hey.there:4000/graphql',
});

async function execute<T>(payload: SubscribePayload) {
  return new Promise<T>((resolve, reject) => {
    let result: T;
    client.subscribe<T>(payload, {
      next: (data) => (result = data),
      error: reject,
      complete: () => resolve(result),
    });
  });
}

// use
(async () => {
  try {
    const result = await execute({
      query: '{ hello }',
    });
    // complete
    // next = result = { data: { hello: 'Hello World!' } }
  } catch (err) {
    // error
  }
})();

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Client usage with AsyncIterator

import { createClient, SubscribePayload } from 'graphql-ws';

const client = createClient({
  url: 'ws://iterators.ftw:4000/graphql',
});

function subscribe<T>(payload: SubscribePayload): AsyncGenerator<T> {
  let deferred: {
    resolve: (done: boolean) => void;
    reject: (err: unknown) => void;
  } | null = null;
  const pending: T[] = [];
  let throwMe: unknown = null,
    done = false;
  const dispose = client.subscribe<T>(payload, {
    next: (data) => {
      pending.push(data);
      deferred?.resolve(false);
    },
    error: (err) => {
      throwMe = err;
      deferred?.reject(throwMe);
    },
    complete: () => {
      done = true;
      deferred?.resolve(true);
    },
  });
  return {
    [Symbol.asyncIterator]() {
      return this;
    },
    async next() {
      if (done) return { done: true, value: undefined };
      if (throwMe) throw throwMe;
      if (pending.length) return { value: pending.shift()! };
      return (await new Promise<boolean>(
        (resolve, reject) => (deferred = { resolve, reject }),
      ))
        ? { done: true, value: undefined }
        : { value: pending.shift()! };
    },
    async throw(err) {
      throw err;
    },
    async return() {
      dispose();
      return { done: true, value: undefined };
    },
  };
}

(async () => {
  const subscription = subscribe({
    query: 'subscription { greetings }',
  });
  // subscription.return() to dispose

  for await (const result of subscription) {
    // next = result = { data: { greetings: 5x } }
  }
  // complete
})();

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Client usage with Observable

import { Observable } from 'relay-runtime';
// or
import { Observable } from '@apollo/client/core';
// or
import { Observable } from 'rxjs';
// or
import Observable from 'zen-observable';
// or any other lib which implements Observables as per the ECMAScript proposal: https://github.com/tc39/proposal-observable

const client = createClient({
  url: 'ws://graphql.loves:4000/observables',
});

function toObservable(operation) {
  return new Observable((observer) =>
    client.subscribe(operation, {
      next: (data) => observer.next(data),
      error: (err) => observer.error(err),
      complete: () => observer.complete(),
    }),
  );
}

const observable = toObservable({ query: `subscription { ping }` });

const subscription = observable.subscribe({
  next: (data) => {
    expect(data).toBe({ data: { ping: 'pong' } });
  },
});

// ⏱

subscription.unsubscribe();

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Client usage with Relay

import { GraphQLError } from 'graphql';
import {
  Network,
  Observable,
  RequestParameters,
  Variables,
} from 'relay-runtime';
import { createClient } from 'graphql-ws';

const subscriptionsClient = createClient({
  url: 'ws://i.love:4000/graphql',
  connectionParams: () => {
    const session = getSession();
    if (!session) {
      return {};
    }
    return {
      Authorization: `Bearer ${session.token}`,
    };
  },
});

// yes, both fetch AND subscribe handled in one implementation
function fetchOrSubscribe(operation: RequestParameters, variables: Variables) {
  return Observable.create((sink) => {
    if (!operation.text) {
      return sink.error(new Error('Operation text cannot be empty'));
    }
    return subscriptionsClient.subscribe(
      {
        operationName: operation.name,
        query: operation.text,
        variables,
      },
      {
        ...sink,
        error: (err) => {
          if (err instanceof Error) {
            return sink.error(err);
          }

          if (err instanceof CloseEvent) {
            return sink.error(
              // reason will be available on clean closes
              new Error(
                `Socket closed with event ${err.code} ${err.reason || ''}`,
              ),
            );
          }

          return sink.error(
            new Error(
              (err as GraphQLError[]).map(({ message }) => message).join(', '),
            ),
          );
        },
      },
    );
  });
}

export const network = Network.create(fetchOrSubscribe, fetchOrSubscribe);

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Client usage with urql

import { createClient, defaultExchanges, subscriptionExchange } from 'urql';
import { createClient as createWSClient } from 'graphql-ws';

const wsClient = createWSClient({
  url: 'ws://its.urql:4000/graphql',
});

const client = createClient({
  url: '/graphql',
  exchanges: [
    ...defaultExchanges,
    subscriptionExchange({
      forwardSubscription(operation) {
        return {
          subscribe: (sink) => {
            const dispose = wsClient.subscribe(operation, sink);
            return {
              unsubscribe: dispose,
            };
          },
        };
      },
    }),
  ],
});

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Client usage with Apollo

import {
  ApolloLink,
  Operation,
  FetchResult,
  Observable,
} from '@apollo/client/core';
import { print, GraphQLError } from 'graphql';
import { createClient, ClientOptions, Client } from 'graphql-ws';

class WebSocketLink extends ApolloLink {
  private client: Client;

  constructor(options: ClientOptions) {
    super();
    this.client = createClient(options);
  }

  public request(operation: Operation): Observable<FetchResult> {
    return new Observable((sink) => {
      return this.client.subscribe<FetchResult>(
        { ...operation, query: print(operation.query) },
        {
          next: sink.next.bind(sink),
          complete: sink.complete.bind(sink),
          error: (err) => {
            if (err instanceof Error) {
              return sink.error(err);
            }

            if (err instanceof CloseEvent) {
              return sink.error(
                // reason will be available on clean closes
                new Error(
                  `Socket closed with event ${err.code} ${err.reason || ''}`,
                ),
              );
            }

            return sink.error(
              new Error(
                (err as GraphQLError[])
                  .map(({ message }) => message)
                  .join(', '),
              ),
            );
          },
        },
      );
    });
  }
}

const link = new WebSocketLink({
  url: 'ws://where.is:4000/graphql',
  connectionParams: () => {
    const session = getSession();
    if (!session) {
      return {};
    }
    return {
      Authorization: `Bearer ${session.token}`,
    };
  },
});

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Client usage with custom retry timeout strategy

import { createClient } from 'graphql-ws';
import { waitForHealthy } from './my-servers';

const url = 'ws://i.want.retry:4000/control/graphql';

const client = createClient({
  url,
  retryWait: async function waitForServerHealthyBeforeRetry() {
    // if you have a server healthcheck, you can wait for it to become
    // healthy before retrying after an abrupt disconnect (most commonly a restart)
    await waitForHealthy(url);

    // after the server becomes ready, wait for a second + random 1-4s timeout
    // (avoid DDoSing yourself) and try connecting again
    await new Promise((resolve) =>
      setTimeout(resolve, 1000 + Math.random() * 3000),
    );
  },
});

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Client usage with graceful restart

import { createClient, Client, ClientOptions } from 'graphql-ws';
import { giveMeAFreshToken } from './token-giver';

interface RestartableClient extends Client {
  restart(): void;
}

function createRestartableClient(options: ClientOptions): RestartableClient {
  let restartRequested = false;
  let restart = () => {
    restartRequested = true;
  };

  const client = createClient({
    ...options,
    on: {
      ...options.on,
      opened: (socket) => {
        options.on?.opened?.(socket);

        restart = () => {
          if (socket.readyState === WebSocket.OPEN) {
            // if the socket is still open for the restart, do the restart
            socket.close(4205, 'Client Restart');
          } else {
            // otherwise the socket might've closed, indicate that you want
            // a restart on the next opened event
            restartRequested = true;
          }
        };

        // just in case you were eager to restart
        if (restartRequested) {
          restartRequested = false;
          restart();
        }
      },
    },
  });

  return {
    ...client,
    restart: () => restart(),
  };
}

const client = createRestartableClient({
  url: 'ws://graceful.restart:4000/is/a/non-fatal/close-code',
  connectionParams: async () => {
    const token = await giveMeAFreshToken();
    return { token };
  },
});

// all subscriptions from `client.subscribe` will resubscribe after `client.restart`

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Client usage with ping/pong timeout and latency metrics

import { createClient } from 'graphql-ws';

let activeSocket,
  timedOut,
  pingSentAt = 0,
  latency = 0;
createClient({
  url: 'ws://i.time.out:4000/and-measure/latency',
  keepAlive: 10_000, // ping server every 10 seconds
  on: {
    opened: (socket) => (activeSocket = socket),
    ping: (received) => {
      if (!received /* sent */) {
        pingSentAt = Date.now();
        timedOut = setTimeout(() => {
          if (activeSocket.readyState === WebSocket.OPEN)
            activeSocket.close(4408, 'Request Timeout');
        }, 5_000); // wait 5 seconds for the pong and then close the connection
      }
    },
    pong: (received) => {
      if (received) {
        latency = Date.now() - pingSentAt;
        clearTimeout(timedOut); // pong is received, clear connection close timeout
      }
    },
  },
});

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Client usage with manual pings and pongs

import {
  createClient,
  Client,
  ClientOptions,
  stringifyMessage,
  PingMessage,
  PongMessage,
  MessageType,
} from 'graphql-ws';

interface PingerClient extends Client {
  ping(payload?: PingMessage['payload']): void;
  pong(payload?: PongMessage['payload']): void;
}

function createPingerClient(options: ClientOptions): PingerClient {
  let activeSocket: WebSocket;

  const client = createClient({
    disablePong: true,
    ...options,
    on: {
      opened: (socket) => {
        options.on?.opened?.(socket);
        activeSocket = socket;
      },
    },
  });

  return {
    ...client,
    ping: (payload) => {
      if (activeSocket.readyState === WebSocket.OPEN)
        activeSocket.send(
          stringifyMessage({
            type: MessageType.Ping,
            payload,
          }),
        );
    },
    pong: (payload) => {
      if (activeSocket.readyState === WebSocket.OPEN)
        activeSocket.send(
          stringifyMessage({
            type: MessageType.Pong,
            payload,
          }),
        );
    },
  };
}

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Client usage supported check

import { createClient } from 'graphql-ws';

function supportsGraphQLTransportWS(url: string): Promise<boolean> {
  return new Promise((resolve) => {
    const client = createClient({
      url,
      retryAttempts: 0, // fail immediately
      lazy: false, // connect as soon as the client is created
      on: {
        closed: () => resolve(false), // connection rejected, probably not supported
        connected: () => {
          resolve(true); // connected = supported
          client.dispose(); // dispose after check
        },
      },
    });
  });
}

const supported = await supportsGraphQLTransportWS(
  'ws://some.unknown:4000/enpoint',
);
if (supported) {
  // use graphql-ws
} else {
  // fallback (use subscriptions-transport-ws?)
}

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Client usage in browser

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>GraphQL over WebSocket</title>
    <script
      type="text/javascript"
      src="https://unpkg.com/graphql-ws/umd/graphql-ws.min.js"
    ></script>
  </head>
  <body>
    <script type="text/javascript">
      const client = graphqlWs.createClient({
        url: 'ws://umdfor.the:4000/win/graphql',
      });

      // consider other recipes for usage inspiration
    </script>
  </body>
</html>

��

Client usage in Node

const ws = require('ws'); // yarn add ws
const Crypto = require('crypto');
const { createClient } = require('graphql-ws');

const client = createClient({
  url: 'ws://no.browser:4000/graphql',
  webSocketImpl: ws,
  /**
   * Generates a v4 UUID to be used as the ID.
   * Reference: https://gist.github.com/jed/982883
   */
  generateID: () =>
    ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, (c) =>
      (c ^ (Crypto.randomBytes(1)[0] & (15 >> (c / 4)))).toString(16),
    ),
});

// consider other recipes for usage inspiration

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Server usage with ws

// minimal version of `import { useServer } from 'graphql-ws/lib/use/ws';`

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { makeServer, CloseCode } from 'graphql-ws';
import { schema } from './my-graphql-schema';

// make
const server = makeServer({ schema });

// create websocket server
const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

// implement
wsServer.on('connection', (socket, request) => {
  // a new socket opened, let graphql-ws take over
  const closed = server.opened(
    {
      protocol: socket.protocol, // will be validated
      send: (data) =>
        new Promise((resolve, reject) => {
          socket.send(data, (err) => (err ? reject(err) : resolve()));
        }), // control your data flow by timing the promise resolve
      close: (code, reason) => socket.close(code, reason), // there are protocol standard closures
      onMessage: (cb) =>
        socket.on('message', async (event) => {
          try {
            // wait for the the operation to complete
            // - if init message, waits for connect
            // - if query/mutation, waits for result
            // - if subscription, waits for complete
            await cb(event.toString());
          } catch (err) {
            // all errors that could be thrown during the
            // execution of operations will be caught here
            socket.close(CloseCode.InternalServerError, err.message);
          }
        }),
    },
    // pass values to the `extra` field in the context
    { socket, request },
  );

  // notify server that the socket closed
  socket.once('close', (code, reason) => closed(code, reason));
});

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Server usage with ws and custom auth handling

// check extended implementation at `{ useServer } from 'graphql-ws/lib/use/ws'`

import http from 'http';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { makeServer, CloseCode } from 'graphql-ws';
import { schema } from './my-graphql-schema';
import { validate } from './my-auth';

// extra in the context
interface Extra {
  readonly request: http.IncomingMessage;
}

// your custom auth
class Forbidden extends Error {}
function handleAuth(request: http.IncomingMessage) {
  // do your auth on every subscription connect
  const good = validate(request.headers['authorization']);
  // or const { iDontApprove } = session(request.cookies);
  if (!good) {
    // throw a custom error to be handled
    throw new Forbidden(':(');
  }
}

// make graphql server
const gqlServer = makeServer<Extra>({
  schema,
  onConnect: async (ctx) => {
    // do your auth on every connect
    await handleAuth(ctx.extra.request);
  },
  onSubscribe: async (ctx) => {
    // or maybe on every subscribe
    await handleAuth(ctx.extra.request);
  },
  onNext: async (ctx) => {
    // haha why not on every result emission?
    await handleAuth(ctx.extra.request);
  },
});

// create websocket server
const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

// implement
wsServer.on('connection', (socket, request) => {
  // you may even reject the connection without ever reaching the lib
  // return socket.close(4403, 'Forbidden');

  // pass the connection to graphql-ws
  const closed = gqlServer.opened(
    {
      protocol: socket.protocol, // will be validated
      send: (data) =>
        new Promise((resolve, reject) => {
          // control your data flow by timing the promise resolve
          socket.send(data, (err) => (err ? reject(err) : resolve()));
        }),
      close: (code, reason) => socket.close(code, reason), // for standard closures
      onMessage: (cb) => {
        socket.on('message', async (event) => {
          try {
            // wait for the the operation to complete
            // - if init message, waits for connect
            // - if query/mutation, waits for result
            // - if subscription, waits for complete
            await cb(event.toString());
          } catch (err) {
            // all errors that could be thrown during the
            // execution of operations will be caught here
            if (err instanceof Forbidden) {
              // your magic
            } else {
              socket.close(CloseCode.InternalServerError, err.message);
            }
          }
        });
      },
    },
    // pass request to the extra
    { request },
  );

  // notify server that the socket closed
  socket.once('close', (code, reason) => closed(code, reason));
});

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Server usage with ws and subprotocol pings and pongs

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import {
  makeServer,
  CloseCode,
  stringifyMessage,
  MessageType,
} from 'graphql-ws';
import { schema } from './my-graphql-schema';

// make
const server = makeServer({ schema });

// create websocket server
const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

// implement
wsServer.on('connection', (socket, request) => {
  // subprotocol pinger because WS level ping/pongs might not be available
  let pinger, pongWait;
  function ping() {
    if (socket.readyState === socket.OPEN) {
      // send the subprotocol level ping message
      socket.send(stringifyMessage({ type: MessageType.Ping }));

      // wait for the pong for 6 seconds and then terminate
      pongWait = setTimeout(() => {
        clearInterval(pinger);
        socket.close();
      }, 6_000);
    }
  }

  // ping the client on an interval every 12 seconds
  pinger = setInterval(() => ping(), 12_000);

  // a new socket opened, let graphql-ws take over
  const closed = server.opened(
    {
      protocol: socket.protocol, // will be validated
      send: (data) => socket.send(data),
      close: (code, reason) => socket.close(code, reason),
      onMessage: (cb) =>
        socket.on('message', async (event) => {
          try {
            // wait for the the operation to complete
            // - if init message, waits for connect
            // - if query/mutation, waits for result
            // - if subscription, waits for complete
            await cb(event.toString());
          } catch (err) {
            // all errors that could be thrown during the
            // execution of operations will be caught here
            socket.close(CloseCode.InternalServerError, err.message);
          }
        }),
      // pong received, clear termination timeout
      onPong: () => clearTimeout(pongWait),
    },
    // pass values to the `extra` field in the context
    { socket, request },
  );

  // notify server that the socket closed and stop the pinger
  socket.once('close', (code, reason) => {
    clearTimeout(pongWait);
    clearInterval(pinger);
    closed(code, reason);
  });
});

��

Server usage with Cloudflare Workers

Please check the worker-graphql-ws-template repo out.

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ws server usage with Express GraphQL

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import express from 'express';
import { graphqlHTTP } from 'express-graphql';
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';

// create express and middleware
const app = express();
app.use('/graphql', graphqlHTTP({ schema }));

const server = app.listen(4000, () => {
  // create and use the websocket server
  const wsServer = new WebSocketServer({
    server,
    path: '/graphql',
  });

  useServer({ schema }, wsServer);
});

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ws server usage with Apollo Server Express

import express from 'express';
import { ApolloServer } from 'apollo-server-express';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';

// create express
const app = express();

// create apollo server
const apolloServer = new ApolloServer({ schema });

// apply middleware
apolloServer.applyMiddleware({ app });

const server = app.listen(4000, () => {
  // create and use the websocket server
  const wsServer = new WebSocketServer({
    server,
    path: '/graphql',
  });

  useServer({ schema }, wsServer);
});

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ws server usage with subscriptions-transport-ws backwards compatibility

import http from 'http';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { execute, subscribe } from 'graphql';
import { GRAPHQL_TRANSPORT_WS_PROTOCOL } from 'graphql-ws';
import { useServer } from 'graphql-ws/lib/use/ws';
import { SubscriptionServer, GRAPHQL_WS } from 'subscriptions-transport-ws';
import { schema } from './my-graphql-schema';

// graphql-ws
const graphqlWs = new WebSocketServer({ noServer: true });
useServer({ schema }, graphqlWs);

// subscriptions-transport-ws
const subTransWs = new WebSocketServer({ noServer: true });
SubscriptionServer.create(
  {
    schema,
    execute,
    subscribe,
  },
  subTransWs,
);

// create http server
const server = http.createServer(function weServeSocketsOnly(_, res) {
  res.writeHead(404);
  res.end();
});

// listen for upgrades and delegate requests according to the WS subprotocol
server.on('upgrade', (req, socket, head) => {
  // extract websocket subprotocol from header
  const protocol = req.headers['sec-websocket-protocol'];
  const protocols = Array.isArray(protocol)
    ? protocol
    : protocol?.split(',').map((p) => p.trim());

  // decide which websocket server to use
  const wss =
    protocols?.includes(GRAPHQL_WS) && // subscriptions-transport-ws subprotocol
    !protocols.includes(GRAPHQL_TRANSPORT_WS_PROTOCOL) // graphql-ws subprotocol
      ? subTransWs
      : // graphql-ws will welcome its own subprotocol and
        // gracefully reject invalid ones. if the client supports
        // both transports, graphql-ws will prevail
        graphqlWs;
  wss.handleUpgrade(req, socket, head, (ws) => {
    wss.emit('connection', ws, req);
  });
});

server.listen(4000);

��

ws server usage with console logging

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    schema,
    onConnect: (ctx) => {
      console.log('Connect', ctx);
    },
    onSubscribe: (ctx, msg) => {
      console.log('Subscribe', { ctx, msg });
    },
    onNext: (ctx, msg, args, result) => {
      console.debug('Next', { ctx, msg, args, result });
    },
    onError: (ctx, msg, errors) => {
      console.error('Error', { ctx, msg, errors });
    },
    onComplete: (ctx, msg) => {
      console.log('Complete', { ctx, msg });
    },
  },
  wsServer,
);

��

ws server usage on a multi WebSocket server

import http from 'http';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import url from 'url';
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';

const server = http.createServer(function weServeSocketsOnly(_, res) {
  res.writeHead(404);
  res.end();
});

/**
 * Two websocket servers on different paths:
 * - `/wave` sends out waves
 * - `/graphql` serves graphql
 */
const waveWS = new WebSocketServer({ noServer: true });
const graphqlWS = new WebSocketServer({ noServer: true });

// delegate upgrade requests to relevant destinations
server.on('upgrade', (request, socket, head) => {
  const pathname = url.parse(request.url).pathname;

  if (pathname === '/wave') {
    return waveWS.handleUpgrade(request, socket, head, (client) => {
      waveWS.emit('connection', client, request);
    });
  }

  if (pathname === '/graphql') {
    return graphqlWS.handleUpgrade(request, socket, head, (client) => {
      graphqlWS.emit('connection', client, request);
    });
  }

  return socket.destroy();
});

// wave on connect
waveWS.on('connection', (socket) => {
  socket.send('��');
});

// serve graphql
useServer({ schema }, graphqlWS);

server.listen(4000);

��

ws server usage with custom context value

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, roots, getDynamicContext } from './my-graphql';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    context: (ctx, msg, args) => {
      return getDynamicContext(ctx, msg, args);
    }, // or static context by supplying the value direcly
    schema,
    roots,
  },
  wsServer,
);

��

ws server usage with dynamic schema

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, checkIsAdmin, getDebugSchema } from './my-graphql';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    schema: async (ctx, msg, executionArgsWithoutSchema) => {
      // will be called on every subscribe request
      // allowing you to dynamically supply the schema
      // using the depending on the provided arguments.
      // throwing an error here closes the socket with
      // the `Error` message in the close event reason
      const isAdmin = await checkIsAdmin(ctx.request);
      if (isAdmin) return getDebugSchema(ctx, msg, executionArgsWithoutSchema);
      return schema;
    },
  },
  wsServer,
);

��

ws server usage with custom validation

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { validate } from 'graphql';
import { schema, myValidationRules } from './my-graphql';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    validate: (schema, document) =>
      validate(schema, document, myValidationRules),
  },
  wsServer,
);

��

ws server usage with custom execution arguments

import { parse, validate } from 'graphql';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, myValidationRules } from './my-graphql';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    onSubscribe: (ctx, msg) => {
      const args = {
        schema,
        operationName: msg.payload.operationName,
        document: parse(msg.payload.query),
        variableValues: msg.payload.variables,
      };

      // dont forget to validate when returning custom execution args!
      const errors = validate(args.schema, args.document, myValidationRules);
      if (errors.length > 0) {
        return errors; // return `GraphQLError[]` to send `ErrorMessage` and stop subscription
      }

      return args;
    },
  },
  wsServer,
);

��

ws server usage accepting only subscription operations

import { parse, validate, getOperationAST, GraphQLError } from 'graphql';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql';

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    onSubscribe: (_ctx, msg) => {
      // construct the execution arguments
      const args = {
        schema,
        operationName: msg.payload.operationName,
        document: parse(msg.payload.query),
        variableValues: msg.payload.variables,
      };

      const operationAST = getOperationAST(args.document, args.operationName);
      if (!operationAST) {
        // returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
        return [new GraphQLError('Unable to identify operation')];
      }

      // handle mutation and query requests
      if (operationAST.operation !== 'subscription') {
        // returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
        return [new GraphQLError('Only subscription operations are supported')];

        // or if you want to be strict and terminate the connection on illegal operations
        throw new Error('Only subscription operations are supported');
      }

      // dont forget to validate
      const errors = validate(args.schema, args.document);
      if (errors.length > 0) {
        // returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
        return errors;
      }

      // ready execution arguments
      return args;
    },
  },
  wsServer,
);

��

ws server and client usage with persisted queries

// �� server

import { parse, ExecutionArgs } from 'graphql';
import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';

// a unique GraphQL execution ID used for representing
// a query in the persisted queries store. when subscribing
// you should use the `SubscriptionPayload.query` to transmit the id
type QueryID = string;

const queriesStore: Record<QueryID, ExecutionArgs> = {
  iWantTheGreetings: {
    schema, // you may even provide different schemas in the queries store
    document: parse('subscription Greetings { greetings }'),
  },
};

const wsServer = new WebSocketServer({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    onSubscribe: (_ctx, msg) => {
      const persistedQuery =
        queriesStore[msg.payload.extensions?.persistedQuery];
      if (persistedQuery) {
        return {
          ...persistedQuery,
          variableValues: msg.payload.variables, // use the variables from the client
        };
      }

      // for extra security you only allow the queries from the store.
      // if you want to support both, simply remove the throw below and
      // graphql-ws will handle the query for you
      throw new Error('404: Query Not Found');
    },
  },
  wsServer,
);

// �� client

import { createClient } from 'graphql-ws';

const client = createClient({
  url: 'ws://persisted.graphql:4000/queries',
});

(async () => {
  const onNext = () => {
    /**/
  };

  await new Promise((resolve, reject) => {
    client.subscribe(
      {
        query: '', // query field is required, but you can leave it empty for persisted queries
        extensions: {
          persistedQuery: 'iWantTheGreetings',
        },
      },
      {
        next: onNext,
        error: reject,
        complete: resolve,
      },
    );
  });

  expect(onNext).toBeCalledTimes(5); // greetings in 5 languages
})();

��

ws server and client auth usage with token expiration, validation and refresh

// �� server

import { WebSocketServer } from 'ws'; // yarn add ws
// import ws from 'ws'; yarn add ws@7
// const WebSocketServer = ws.Server;
import { useServer } from 'graphql-ws/lib/use/ws';
import { CloseCode } from 'graphql-ws';
import { schema } from './my-graphql-schema';
import { isTokenValid } from './my-auth';

const wsServer = new WebSocket.Server({
  port: 4000,
  path: '/graphql',
});

useServer(
  {
    schema,
    onConnect: async (ctx) => {
      // do your auth check on every connect
      if (!(await isTokenValid(ctx.connectionParams?.token)))
        // returning false from the onConnect callback will close with `4403: Forbidden`;
        // therefore, being synonymous to ctx.extra.socket.close(4403, 'Forbidden');
        return false;
    },
    onSubscribe: async (ctx) => {
      // or maybe on every subscribe
      if (!(await isTokenValid(ctx.connectionParams?.token)))
        return ctx.extra.socket.close(CloseCode.Forbidden, 'Forbidden');
    },
    onNext: async (ctx) => {
      // why not on every result emission? lol
      if (!(await isTokenValid(ctx.connectionParams?.token)))
        return ctx.extra.socket.close(CloseCode.Forbidden, 'Forbidden');
    },
  },
  wsServer,
);

// �� client

import { createClient, CloseCode } from 'graphql-ws';
import {
  getCurrentToken,
  getCurrentTokenExpiresIn,
  refreshCurrentToken,
} from './my-auth';

// non-fatal WebSocket connection close events will cause the
// client to automatically reconnect. the retries are silent, meaning
// that the client will not error out unless the retry attempts have been
// exceeded or the close event was fatal (read more about the fatal
// close events in the documentation). additionally, all active subscriptions
// will automatically resubscribe upon successful reconnect. this behaviour
// can be leveraged to implement a secure and sound way of authentication;
// handling server-side validation, expiry indication and timely token refreshes

// indicates that the server closed the connection because of
// an auth problem. it indicates that the token should refresh
let shouldRefreshToken = false,
  // the socket close timeout due to token expiry
  tokenExpiryTimeout = null;

const client = createClient({
  url: 'ws://server-validates.auth:4000/graphql',
  connectionParams: async () => {
    if (shouldRefreshToken) {
      // refresh the token because it is no longer valid
      await refreshCurrentToken();
      // and reset the flag to avoid refreshing too many times
      shouldRefreshToken = false;
    }
    return { token: getCurrentToken() };
  },
  on: {
    connected: (socket) => {
      // clear timeout on every connect for debouncing the expiry
      clearTimeout(tokenExpiryTimeout);

      // set a token expiry timeout for closing the socket
      // with an `4403: Forbidden` close event indicating
      // that the token expired. the `closed` event listner below
      // will set the token refresh flag to true
      tokenExpiryTimeout = setTimeout(() => {
        if (socket.readyState === WebSocket.OPEN)
          socket.close(CloseCode.Forbidden, 'Forbidden');
      }, getCurrentTokenExpiresIn());
    },
    closed: (event) => {
      // if closed with the `4403: Forbidden` close event
      // the client or the server is communicating that the token
      // is no longer valid and should be therefore refreshed
      if (event.code === CloseCode.Forbidden) shouldRefreshToken = true;
    },
  },
});

Documentation

Check the docs folder out for TypeDoc generated documentation.

How does it work?

Read about the exact transport intricacies used by the library in the GraphQL over WebSocket Protocol document.

Want to help?

File a bug, contribute with code, or improve documentation? Read up on our guidelines for contributing and drive development with yarn test --watch away!

Disclaimer

This library and the GraphQL over WebSocket Protocol are not cross-compatible with the legacy subscriptions-transport-ws and its accompanying Protocol.

You must use graphql-ws coherently and implement the GraphQL over WebSocket Protocol on both sides, server and the client.

使用案例

nodejs中graphql的服务端和客户端实现

先简单介绍一下GraphQL。 GraphQL 是一门出自Facebook，用于api的查询语言，被称作是Restful的替代品，已经有越来越多的公司和系统使用GraphQL来代替Restful。它的几个主要特点是： 1、只返回你想要的数据。传统Restful中返回的是对象的所有字段，而往往我们需要的只是其中几个字段，这样无疑造成了很大的带宽浪费。GraphQL中由你定义你的查询请求，
GraphQL 客户端开发

前置知识传送门 GraphQL入门四. 客户端开发 4.1 基本查询按需获取需要的数据 // 定义类型 const typeDefs = gql` type Hero { name: String age: Int } # 查询类型 type Query { hero: Hero } `; // resolver 函数 const resolv