socket.test.js

const { Server } = require("socket.io");
const Client = require("socket.io-client");
const { escape } = require('validator');
let io, serverSocket, clientSocket;

beforeAll((done) => {
  io = new Server(3000);
  const sanitize = require('./middleware/socket/sanitize');
  io.use(sanitize);
  clientSocket = new Client("http://localhost:3000");
  io.on("connection", (socket) => {
    serverSocket = socket;
  });
  clientSocket.on("connect", done);
});

afterAll(() => {
  io.close();
  clientSocket.close();
});

describe("Sanitization Middleware", () => {
  it("should sanitize incoming string data", (done) => {
    const payload = "<h1>Hi</h1>";
    const sanitizedPayload = escape(payload); // escaping logic using `validator`

    clientSocket.emit("testEvent", {payload});

    serverSocket.on("testEvent", (data) => {
      expect(data.payload).toBe(sanitizedPayload);
      done();
    });
  });
});

/** 
 * FAILED ExPERIMENTAL MIDDLEWARE
 */
/*
const { Server } = require("socket.io");
const Client = require("socket.io-client");
let io, serverSocket, clientSocket;

beforeAll((done) => {
  io = new Server(3000);
  const sanitize = require('./middleware/socket/sanitize.experimental');
  io.use(sanitize);
  clientSocket = new Client("http://localhost:3000");
  io.on("connection", (socket) => {
    serverSocket = socket;
  });
  clientSocket.on("connect", done);
});

afterAll(() => {
  io.close();
  clientSocket.close();
});

describe("Sanitization Middleware", () => {
  it("should sanitize incoming string data", (done) => {
    const payload = { message: "{ $ne: null }" }; // NoSQL Injection attempt
    const expectedSanitizedPayload = { message: "{  ne: null }" }; // '$' should be removed

    clientSocket.emit("testEvent", payload);

    serverSocket.on("testEvent", (data) => {
      expect(data).toEqual(expectedSanitizedPayload);
      console.log(data);
      done();
    });
  });
});

*/