Architecture

Dependencies

The project relies on a minimal set of dependencies to ensure lightweight and efficient execution:

• Express: Web server framework for handling HTTP requests.
• Zod: Schema validation for runtime type checking.
• Dotenv: Environment variable management.

Development dependencies include Jest for testing, TypeDoc for documentation, and ESLint/Prettier for code quality.

Testing Framework

The project uses Jest as the primary testing framework.

• Integration/E2E Tests: Located in the tests/ directory (e.g., e2e.spec.ts).
• Unit Tests: Co-located with source files (e.g., src/Domain/ValueObjects/Pokemon.spec.ts).

Tracing Technique

Tracing is implemented via a custom TracingMiddleware.

• Location: src/Infrastructure/Http/Middlewares/TracingMiddleware.ts
• Mechanism: uses AsyncLocalStorage to store and propagate a correlation ID for each request.
• Integration: The correlation ID is passed to the Logger to ensure all logs for a specific request can be traced back to a single event chain.

Folder Structure

The project follows Clean Architecture principles to separate concerns into distinct layers:

• src/Domain/: Contains the core business logic, entities, and repository interfaces (Ports). usage of this layer is independent of any external agency.
• src/Application/: Contains the application logic and use cases (Queries and Commands). It orchestrates the flow of data between the Domain and Infrastructure layers.
• src/Infrastructure/: Contains the implementation of the interfaces defined in the Domain layer (Adapters). This includes database repositories, external API clients, and the HTTP server setup.