Vending Machine API

Exercise Brief

Design an API for a vending machine, allowing users with a “seller” role to add, update, or remove products, while users with a “buyer” role can deposit coins into the machine and make purchases. The vending machine should only accept 5, 10, 20, 50, and 100 cent coins.

Tasks

• Framework of choice: FastAPI
• REST API consuming and producing “application/json”
• Implement CRUD for users (POST doesn’t require authentication)
• Implement CRUD for a product model (GET can be called by anyone, while POST, PUT, and DELETE can be called only by the seller user who created the product)
• Implement /deposit endpoint so users with a “buyer” role can deposit coins into their vending machine account
• Implement /buy endpoint (accepts productId, amount of products) so users with a “buyer” role can buy products with the money they’ve deposited
• Implement /reset endpoint so users with a “buyer” role can reset their deposit

Evaluation Criteria

• Edge cases covered
• Bonus: API tests
• Attention to security
• Dockerized

Deliverables

• Github repository
• Postman collection or Swagger documentation

Usage

To run the solution locally:

1. Clone this repository.
2. Ensure Docker is installed on your machine.
3. Navigate to the root directory of the project.
4. Make sure the .env file is setup properly. Two fields required are DATABASE_URI and SECRET_KEY
5. Run docker-compose up -d --build to build and start the Docker containers.
6. Run docker exec vendor-machine-api pytest to run the test cases.
7. Access the Swagger documentation at http://localhost:port_number/api/docs to explore and test the API endpoints.