[Nitro][Nuxt3] How to get nitro handler's event inside socket events

[xiaosasori]

I am following the documentation, but I can't figure out how to get the handler's event inside socket events.
I need it to retrieve user credentials from event.context.

import type { NitroApp } from "nitropack";
import { Server as Engine } from "engine.io";
import { Server } from "socket.io";
import { defineEventHandler } from "h3";

export default defineNitroPlugin((nitroApp: NitroApp) => {
  const engine = new Engine();
  const io = new Server();

  io.bind(engine);

  io.on("connection", (socket) => {
    // I want to access to handler's event here...
  });

  nitroApp.router.use("/socket.io/", defineEventHandler({
    handler(event) {
      engine.handleRequest(event.node.req, event.node.res);
      event._handled = true;
    },
    websocket: {
      open(peer) {
        const nodeContext = peer.ctx.node;
        const req = nodeContext.req;

        // @ts-expect-error private method
        engine.prepare(req);

        const rawSocket = nodeContext.req.socket;
        const websocket = nodeContext.ws;

        // @ts-expect-error private method
        engine.onWebSocket(req, rawSocket, websocket);
      }
    }
  }));
});

Thank you in advance! 🙏

[darrachequesne]

Hi! I think the easiest way is to keep a reference to the event.context object on the req object:

import type { NitroApp } from "nitropack";
import { Server as Engine } from "engine.io";
import { Server } from "socket.io";
import { defineEventHandler } from "h3";

export default defineNitroPlugin((nitroApp: NitroApp) => {
  const engine = new Engine();
  const io = new Server();

  io.bind(engine);

  io.on("connection", (socket) => {
    const context = socket.request.context;
  });

  nitroApp.router.use("/socket.io/", defineEventHandler({
    handler(event) {
      event.node.req.context = event.context;
      engine.handleRequest(event.node.req, event.node.res);
      event._handled = true;
    },
    websocket: {
      open(peer) {
        const nodeContext = peer.ctx.node;
        const req = nodeContext.req;

        // @ts-expect-error private method
        engine.prepare(req);

        const rawSocket = nodeContext.req.socket;
        const websocket = nodeContext.ws;

        // @ts-expect-error private method
        engine.onWebSocket(req, rawSocket, websocket);
      }
    }
  }));
});