sockifyClient creates a mock Socket.IO client that intercepts function calls on a dependency object and emits events to a server, enabling testing of Socket.IO interactions in a serverless context.

Run example

npm run import -- "Mock any module with promisify and socket.io-client"

Mock any module with promisify and socket.io-client

var client = require('socket.io-client');

function sockifyClient(req, dep, host) {
    let ctx;
    ctx = automock.mockValue(req, {
        stubCreator: (name) => {
            return function () {
                var args = ['call', dep, name.split('.')[1]];
                for (var i = 0; i < arguments.length; i++) {
                    args[args.length] = arguments[i];
                }
                socket.emit.apply(socket, args);
            };
        },
        name: dep
    });
    var promises = promisifyMock(ctx, dep);
    promises.___close = () => socket.emit('close');
    var socket = client.connect(host);
    socket.on('connect', function () {
        // TODO: socket.emit('handler') service provider
        socket.emit('require', dep, function () {

        });
        socket.on('resolve', function () {

        });
    });
    return promises;
};
module.exports = sockifyClient;

const socketIO = require('socket.io-client');

/**
 * Creates an automated client socket with mock functionality.
 *
 * @param {object} req - The request object.
 * @param {string} dep - The dependency name.
 * @param {string} host - The socket.io host.
 * @returns {Promise} A promise that resolves with the socket instance.
 */
function sockifyClient(req, dep, host) {
    const socket = socketIO.connect(host);

    // Initialize the mock stub
    const mockStub = automock.mockValue(req, {
        stubCreator: (name) => {
            const args = ['call', dep, name.split('.').pop()];

            // Prepend the stub with the mock dependencies
            for (const arg of args.slice(1)) {
                args[1] = arg;
            }

            return () => socket.emit.apply(socket, args);
        },
        name: dep
    });

    // Promisify the mock stub
    const { promises } = promisifyMock(mockStub, dep);

    // Attach a close event handler
    promises.___close = () => socket.emit('close');

    // Set up socket events
    socket.on('connect', () => {
        socket.emit('require', dep, () => {});

        // Setup resolve event handler
        socket.on('resolve', () => {});
    });

    return promises;
}

module.exports = sockifyClient;

The code defines a function sockifyClient that creates a mock client for a Socket.IO server.

Functionality:

1. Mock Context Creation:

   • Uses automock.mockValue to create a mock context (ctx) for the request object (req).
   • Defines a stub creator function within the mock context that intercepts function calls on the dependency object (dep).
   • When a function is called on dep, it emits an event to the Socket.IO server with the function name and arguments.

2. Promise-Based Mocking:

   • Uses promisifyMock to create promise-based versions of the mocked functions.

3. Socket.IO Connection:

   • Establishes a connection to the Socket.IO server at the specified host.
   • Emits events to the server to register the dependency and handle responses.

4. Return Value:

   • Returns the promise-based mocked functions.

Purpose:

The code likely aims to facilitate testing and mocking of Socket.IO interactions within a serverless environment.