14 testing

14 — Testing

The test project, conventions, coverage, and how to run the tests. Related: ManualTests.md (manual checklist) · 02 — Projects & Solution

Project

• SimpleLauncher.Tests — xUnit (net10.0-windows), references SimpleLauncher (and transitively SimpleLauncher.Core); InternalsVisibleTo gives access to internal members.
• Frameworks: xUnit, Moq 4.20.72, Serilog ILogger mocks via NoOpLogger; Meziantou analyzer enabled.
• 150 test files (~2000 tests). Parallelization is disabled (AssemblyInfo.cs: CollectionBehavior(DisableTestParallelization = true)) because several tests share static/WPF state.

Test helpers (SimpleLauncher.Tests\TestHelpers\)

Helper	Purpose
NoOpLogger	Serilog ILogger that discards everything
NoOpMessageBoxLibraryService	Stub for IMessageBoxLibraryService (large; all methods)
NoOpCredentialProtector	Plaintext credential protector for settings tests
NoOpGetListOfFiles / NoOpResourceProvider	Other no-op stubs
ServiceProviderMock	Installs a fake IServiceProvider where static access is required
ProjectPathHelper	Resolves repo-relative paths for tests (e.g. parameters.md)
StaApartment	Runs test actions on an STA thread (with optional WPF Application) for headless UI tests

What is covered (summary)

Unit tests cover the core logic layer: settings & system manager persistence, favorites, play history, game scanner core, file finder, search orchestrator, launch strategies (default, DOSBox, Commander Genius, CHD/CUE, PBP, XISO, ZIP), mount-strategy matching, Core emulator config-injection services, models/DTOs, path/URL/sanitizer/pagination/filter helpers, RetroAchievements manager/matcher/hasher, Steam VDF parser, update-check logic, API connectivity, converters' strategy classes — plus the batch added in 5.6.x: parameter resolver API service, system.xml writer + emulator XML helpers, game file watcher, loading overlay, UI reset, status bar, menu check-marks, credential protector (DPAPI), system-selection ViewModel, default-folder/temp/missing-file services.

What is not covered (windows, Views, ViewModels, live file operations, store scanners, gamepad/audio, RA API layer, per-emulator launch handlers) — see ManualTests.md for the full manual checklist.

Running the tests

# build + run everything
dotnet test SimpleLauncher.Tests/SimpleLauncher.Tests.csproj

# run a single class or feature
dotnet test SimpleLauncher.Tests/SimpleLauncher.Tests.csproj \
  --filter "FullyQualifiedName~GameFileWatcherServiceTests"

# run everything except the slow network/integration tests
dotnet test SimpleLauncher.Tests/SimpleLauncher.Tests.csproj \
  --filter "FullyQualifiedName!~IntegrationTests&FullyQualifiedName!~ApiConnectivity&FullyQualifiedName!~StatsApiConnection&FullyQualifiedName!~UpdateSimulation&FullyQualifiedName!~RetroAchievementsManager"

⚠ Known slow test: UrlValidationTests.ParametersMdAllUrlsAreReachable pings every URL in parameters.md over the network without a timeout — it can take 15+ minutes or hang when a URL is unreachable. Exclude it (or fix it with a CancellationToken timeout) for local runs.

Writing new tests — conventions

• One test file per production class: XxxTests.cs; test class name matches the target.
• using Xunit; explicitly (no global using).
• Mock interfaces with Moq; use real temp directories for filesystem services (Path.GetTempPath() + GUID, cleanup in Dispose).
• WPF-touching tests run inside StaApartment.Run/RunAsync (see LoadingOverlayServiceTests, MenuCheckMarkServiceTests, UiResetServiceTests).
• Timing-based tests (watcher debounce) keep delays small and use TaskCompletionSource + WaitAsync timeouts.
• String assertions use StringComparer.Ordinal overloads (Meziantou MA0002/MA0074).

Related docs

• ManualTests.md
• 15 — Development
• 13 — Logging & Debug