Bitcoin Price Guessing Game

This is a web app that allows users to make guesses on whether the market price of Bitcoin (BTC/USD) will be higher or lower after one minute.

Functionality

Users can:

• See their current score and the latest available BTC price in USD
• Choose to enter a guess of either "up" or "down"
• Only make one guess at a time (each 60s)
• Have their guess resolved when the price changes and at least 60 seconds have passed since the guess was made
• Get 1 point added to their score if their guess is correct, or lose 1 point if their guess is incorrect
• Start with a score of 0
• The can close their browser and return to see their score and continue to make more guesses

How to run the application

The project consists of a client (ReactJS, TailwindCSS) and a server (NodeJS, ExpressJS, AWS - DynamoDB) written in TypeScript.

To run the app locally, follow these steps:

Client

To run the client:

1. Navigate to the /client folder in your terminal.
2. Run npm install to install the required dependencies.
3. Run npm run start to start the development server.

Server

To run the server:

1. Navigate to the /server folder of the project in your terminal.
2. Run npm install to install the required dependencies.
3. In /server/config duplicate the file aws-config_dev.json as aws-config.json and add your aws credentials.
4. Run npm run migrate to execute database migrations.
5. Run npm run build to build the server project.
6. Run npm run start to start the server.

Code Improvements

1. Move Server to a DDD Approach - Refactor the server code to follow a Domain-Driven Design (DDD) approach. This would involve creating necessary copies of entities, such as the Player and Guess entities, to avoid tight coupling and promote modularity;

2. Improve test coverage - Although there are currently some unit tests in the server code, it is recommended to further improve the test coverage to ensure the reliability and stability of the application;

3. Improve error handling - Enhance error handling in the server code by adding appropriate error messages and codes, and implementing appropriate error-handling mechanisms;

4. Use environment variables for configuration;

5. Implement E2E testing: Write automated tests for the server and client code to ensure that the application functions as expected;

App Improvements

1. Prevent simultaneous guesses: To prevent the possibility of a user making two simultaneous guesses by copying their browser's localStorage value to another browser, the server-side code should be updated. Whenever the server receives a guess from a player, it should automatically resolve all pending guesses associated with that player ID.