Creating the project

We will implement the backend of our web chat application in the node, so the first thing is to create a folder to store our project and, inside this folder, start the project using the following command:

    npm init

This command will ask you for a lot of metadata for the project. You can leave all the defaults in force, just hitting Enter until the end. After this we need to install some libraries we will use to implement our project; the first one is RxJS, and to install it you must type the following command:

    npm install rx@4.1.0 --save

We also need a library to implement our WebSocket server: we will use the most famous library to implement WebSocket in JavaScript socket.io with the following command:

    npm install socket.io@1.7.3 --save

We will use express to serve the HTML page of our client, so we need to install it:

    npm install --save express@4.15.2

Lastly, we need...