The BlackJack App

A WebSocket implementation of the blackjack game using Node.js, React.js and CSS.

Supported Features

About the app:

• Multiplayer
• Sounds in the UI
• Mobile friendly

Players can:

• Bet
• Hit
• Stand
• Split
• Double-down

Notes for this version of the game:

• Black-Jack pays 3 : 2
• Black-Jack beats 21
• Surrender is not supported
• Spliting aces is restricted
• The maximum bet is limited by the amount of money the player has

Configurable:

• Number of decks: 6
• Minimum allowed bet: 10
• Initial amount of every player: 1000

How to play

1. Choose a name and click Register.

2. You are redirected to the waiting room. When every player is ready (or just you) one of you must click Start Game.

3. Round has started! Every one should decide their wager. You cannot perform any action (apart from exiting the game by click the Exit Game button) until every player has bet.

4. It is the first player's turn! If it is you, you can choose to hit (draw a card), stand (stop and finish your turn), split (if possible) or double down. Otherwise, you need to wait for your turn.

5. After every player has played, you can see if the result is a win, a defeat or a tie.

6. To start another round with the same players click the Next Round button and play again.

7. You can also play in separate rooms. For example one player could exit the game and start the game while the others are already in a room. This will create a new room for that player while the others will continue playing together.

8. Finally, if you do something "unexpected", you will be notified with a toast notification message.

Setup Instructions (development)

1. Clone the repository.

2. Install node dependencies (skip this step if using the devcontainer).

   cd server_app && npm i && cd -
   cd client_app && npm i && cd -
   

3. Run the server and client applications by opening two terminal windows. For the server:

   cd server_app
   npm run dev
   

   and for the client:

   cd client_app
   npm start
   

Tests

Tests are also implemented to validate the behavior of the game.

• To run all the tests you can run:

  npm test
  

• for the unit tests only run:

  npm run test:unit
  

• and for the integration tests (not implemented yet) run:

  npm run test:int
  

Some notes about the architecture

The architecture is structured in a way that attempts to decouple the game/business logic from the delivery mechanism used to expose the game (WebSockets).

The idea is that the main file index.js creates a WebSocket server that uses the ConnectionHandler class to open a connection, handle input messages, or close a connection. The ConnectionHandler class then uses the GameHandler class to keep a list of all the games (either completed or active) and is responsible for forwarding commands to each Game. It must be noted that there are some commands that the user can instruct that are related to the Game (for example End-Game) and others that are related to a particular Round (for example Hit).

Each Game consists of multiple Rounds and serves multiple Clients. Furthermore, each Round must have one or more decks of Cards (GameCards class) that the Dealer will use to deal the Cards to the players.

In a Round we have two types of Participants, the Players and the Dealer which is unique in each game.

A Player takes a Client object via Dependency Injection as each Player is assigned to one and only Client. However, a Client might belong to two Players in case of split. In this case, two Player objects are used to manipulate the same Client object and transfer the amount of money that the player either won or lost.

By Konstantinos Letros (kosletr)