socks-io

Your socks for the socket-io. Just a very simple non-blocking mocking lib, but useful if you don't care about the server and just want to test the clients interactions. Supports socket.on, socket.emit and socket.open.

Contents

• Installation
• Usage
• Notes

Installation

yarn add socks-io

or

npm i socks-io

Usage

In this example Session is a class responsible for handling a client interactions we want to test. Let's add two clients to the server and let them interact with each other. To do so, we just need to mock the implementation of the socket-io connect function, attach our clients and just run the tests. More below :)

import { connect as socketClient } from "socket.io-client";
import { Session } from "mySocketSessionHandler";
import { SocketServerMock, SocketClientMock } from "./socket.mock";
 
let COUNT = 0;
const SServer = new SocketServerMock(); //global server instance
 
// mock the connect(endpoint, socketConfig)
jest.spyOn(socketClient, "connect").mockImplementation(() => {
  const _socketClientMock = new SocketClientMock(COUNT.toString(), SServer);
  // we need to add a clients to the server so they can interact with each other
  SServer.addClient(_socketClientMock);
  COUNT++;
  return _socketClientMock;
});
 
describe("Session", () => {
  let user1Session;
  let user2Session;
 
  beforeEach(() => {
    SServer.reset(); // isolate the tests
    user1Session = new Session();
    user2Session = new Session();
  });
 
  it("should fire the Example signal after we run the sessions", (done) => {
    // wait for handleExampleSignal function to be called
    jest.spyOn(user1Session, "handleExampleSignal").mockImplementation(() => {
      done();
    });
 
    // start the sessions
    user1Session.run();
    user2Session.run();
  });
 
  it("should fire the YesSignal signal after the user1 ui interaction", (done) => {
    jest.spyOn(user1Session, "openYesNoModal").mockImplementation(() => {
      // mock the user interaction
      user1Session.userAgreed();
      user1Session.sendYesSignal();
    });
 
    jest.spyOn(user2Session, "onYesSignal").mockImplementation(() => {
      done();
    });
 
    user1Session.run();
    user2Session.run();
  });
});

Notes

Emit socket.emit('/join', 'room) to join a room, and SServer.rooms to check who's inside.