@nestjs/graphql/dist/services/gql-subscription.service.js

Nest - modern, fast, powerful node.js web framework (@graphql)

import { execute as graphqlExecute, subscribe as graphqlSubscribe, } from 'graphql';
import { GRAPHQL_TRANSPORT_WS_PROTOCOL, } from 'graphql-ws';
import { useServer } from 'graphql-ws/use/ws';
import { WebSocketServer } from 'ws';
export class GqlSubscriptionService {
    constructor(options, httpServer) {
        this.options = options;
        this.httpServer = httpServer;
        this.wss = new WebSocketServer({
            path: this.options['graphql-ws']?.path ??
                this.options.path,
            noServer: true,
        });
        this.initialize();
    }
    initialize() {
        const { execute = graphqlExecute, subscribe = graphqlSubscribe } = this.options;
        if ('graphql-ws' in this.options) {
            const graphqlWsOptions = this.options['graphql-ws'] === true ? {} : this.options['graphql-ws'];
            this.wsGqlDisposable = useServer({
                schema: this.options.schema,
                execute,
                subscribe,
                context: this.options.context,
                ...graphqlWsOptions,
            }, this.wss);
        }
        this.httpServer.on('upgrade', (req, socket, head) => {
            const protocol = req.headers['sec-websocket-protocol'];
            let protocols = Array.isArray(protocol)
                ? protocol
                : protocol?.split(',').map((p) => p.trim());
            protocols = protocols?.filter((supportedProtocol) => supportedProtocol === GRAPHQL_TRANSPORT_WS_PROTOCOL);
            const wss = this.wss;
            if (req.url?.startsWith(wss.options.path)) {
                wss.handleUpgrade(req, socket, head, (ws) => {
                    wss.emit('connection', ws, req);
                });
            }
        });
    }
    async stop() {
        await this.wsGqlDisposable?.dispose();
    }
}