tdd-dotnet

name	tdd-dotnet
description	Write a new feature using Red-Green-Refactor TDD with xUnit and FluentAssertions for PlaylistMiner .NET backend.

TDD Feature Implementation (.NET)

Implement the requested feature using strict Red-Green-Refactor TDD.

Step 1: Red — Write Failing Tests

1. Create test class in tests/PlaylistMiner.UnitTests/ matching the source file location
2. Name tests: Test_MethodName_Scenario_ExpectedResult
3. Use FluentAssertions: .Should().Be(), .Should().Contain(), .Should().Throw<>()
4. Use Moq for dependencies: var mock = new Mock<IService>()
5. Follow Arrange-Act-Assert pattern
6. Run dotnet test — confirm tests FAIL

Step 2: Green — Minimal Implementation

1. Write the minimum code to make tests pass
2. No refactoring, no optimization, no extras
3. Run dotnet test — confirm tests PASS

Step 3: Refactor

1. Clean up implementation while keeping tests green
2. Extract interfaces, rename variables, reduce duplication
3. Run dotnet test — confirm tests still PASS

Rules

• NEVER write implementation before the test
• One test class per production class
• Use [Category("Unit")] for unit tests, [Category("Integration")] for integration tests
• Integration tests use Testcontainers (real PostgreSQL)
• All async methods accept CancellationToken
• Return DTOs from Core, never EF entities