Dear candidate, thank you to join our code test interview.

To start code test

1. Fork this repository
2. Create new branch
3. Do your code in new branch
4. Create the PR to merge back to main in your repository
5. Share your PR link to us 😀

Kindly notes: for the code test

• You don't need to write a complete implementation code. Only simple and minimum code to demonstrate your idea, and your solution to solve the problem.
• We would like to see how you will solve the problem in code and your solution for it.

We are expecting you to demonstrate mastery in the following areas:

• Clean & Maintainable Code
• Test-Driven Development
• SOLID principles
• KISS principles
• Design Patterns

A huge plus is you will demonstrate:

• Domain-Driven Development
• CQRS approach
• Event Sourcing
• Behavior-Driven Development

---

NodeJs with ExpresJS + Typescript will be used for code & unit tests.

• Use any IDE you want.
• Use any unit test framework you love.
• Update and change any settings, or configurations in the projects as you want.

For data storage,

• You could choose to use a real database (MySQL, Postgres) or fake data (JSON file, the object in NodeJs, or any).

Tasks: API implementation

1. Site and Game APIs: get, add, update, delete

• 1 site can have many games
• Site code is unique
• Game code is unique

{
    "site": {
        "id": number,
        "code": string,
        "games": [
            {
                "id": number,
                "code": string
            }
        ]
    }
}

2. Transactions API

• Method Post: two actions "play" and "win"

• Has idempotency check with "id" ref here https://www.oreilly.com/library/view/hands-on-restful-api/9781788992664/f75ee8f9-056b-41df-b250-e40f0fdfd639.xhtml

• Concurrent: one player can only play 1 game at the same time.

• Amount: will accumulate in playerBalance by each player.

  • + with win
  • - with play

• Can not play if the playerBalance is less than zero, throw error.

• Can not play if the amount less than zero, throw an error.

• Can not win if the amount less than zero, throw an error.

• If the player wins a big amount - greater than 100: send a notification to the system.

  • Notes: implement send a notification is code pattern only.

Request:

{
    "transaction": {
        "id": number,
        "playerId": number,
        "action": "play or win",
        "amount": number,
        "gameId": number,
    }
}

Response:

On Success

{
    "id": number,
    "playerBalance": number
}

On Error:

{
    "code": string,
    "message": string
}

3. (Optional - plug if you could do) Docker & CI setup

• Add the dockerfile
• Add .yml for Github actions