testing-strategy

Testing Strategy

Implement the testing pyramid with domain unit tests, integration tests for repositories, and e2e tests for API endpoints, following consistent naming and fixture patterns.

When to Use

• Writing tests for new features or bug fixes
• Setting up test infrastructure for a new project
• Improving test coverage on existing code
• Reviewing test quality and naming conventions
• Configuring CI/CD test pipelines

Available Operations

1. Write unit tests for domain entities and value objects
2. Write integration tests for repositories and external services
3. Write e2e tests for API endpoints
4. Configure test fixtures and factories
5. Run tests and measure coverage
6. Set up test pipelines in CI/CD

Multi-Step Workflow

Step 1: Understand the Testing Pyramid

        /  E2E  \          Few, slow, expensive
       / Integr. \         Moderate count
      / Unit Tests \       Many, fast, cheap

• Unit tests: Test domain logic in isolation. No database, no HTTP, no external services.
• Integration tests: Test adapters (repositories, clients) against real infrastructure.
• E2E tests: Test full API request/response cycles.

Step 2: Write Unit Tests for Domain Entities

Test business rules without any infrastructure dependency.

# tests/domain/test_demand.py
import pytest

class TestDemand:
    def test_should_decompose_new_demand(self):
        demand = Demand(id=DemandId.generate(), description="Create CRUD")
        planner = FakePlanner(tasks=[Task(...), Task(...)])

        tasks = demand.decompose(planner)

        assert len(tasks) == 2
        assert demand.status == DemandStatus.PLANNED

    def test_should_reject_decompose_if_already_planned(self):
        demand = Demand(id=DemandId.generate(), description="Create CRUD")
        demand.decompose(FakePlanner(tasks=[Task(...)]))

        with pytest.raises(DemandAlreadyDecomposedException):
            demand.decompose(FakePlanner(tasks=[]))

    def test_should_not_allow_more_than_20_tasks(self):
        demand = Demand(id=DemandId.generate(), description="Mega project")
        for i in range(20):
            demand.add_task(Task(...))

        with pytest.raises(TooManyTasksException):
            demand.add_task(Task(...))