Use when writing, editing, refactoring, or debugging tests anywhere under `tests/**` (unit, integration, or end-to-end); authoring NUnit 4 test classes (`*Test`, `*IntegrationTest`); using NSubstitute mocks, AutoFixture with `[AutoMockData]` / `[InlineAutoMockData]` / `[Frozen]`, or AwesomeAssertions (NOT FluentAssertions); working with `CliIntegrationFixture`, `IntegrationTestFixture`, `MockFileSystem`, `TestableLogger`, `NUnitAnsiConsole`, or `New*` factory helpers; adding or updating E2E fixtures under `tests/Recyclarr.Cli.IntegrationTests.E2E/`; editing `Fixtures/recyclarr.yml`, `metadata.json`, `cf/`, `cf-groups/`, or `quality-profiles/` fixture folders; running `Run-E2ETests.ps1` or `scripts/coverage.py`; investigating flaky tests, coverage gaps, or Testcontainers setup. Triggers on phrases like "write a test", "fix this test", "improve coverage", "add an E2E case", "mock this dependency", or any edit to `*.Tests.csproj` or files under `tests/**`.
Use when writing, editing, or reviewing ASP.NET Core Minimal API endpoints, route handlers, route groups, endpoint filters, or API responses; configuring OpenAPI document generation or build-time spec export; implementing endpoint validation or problem details error handling; using Server-Sent Events for streaming; writing integration tests against API endpoints; embedding Kestrel in a CLI tool. Triggers on phrases like "add an endpoint", "minimal API", "route group", "endpoint filter", "typed results", "OpenAPI spec", "Kestrel server", "API endpoint", "HTTP server endpoints". Do NOT use for MVC controllers, Razor Pages, Blazor Server, or SignalR hubs.
Use when adding, editing, or reorganizing entries in `CHANGELOG.md`; drafting release notes for Recyclarr; deciding which Keep a Changelog section (Added, Changed, Deprecated, Removed, Fixed, Security) a change belongs under; wording user-facing entries for `feat`, `fix`, `perf`, or breaking commits; phrasing deprecation notices or migration guidance; preparing the `[Unreleased]` section for cut. Triggers on phrases like "update the changelog", "add a changelog entry", "bump the changelog", "release notes", or any edit touching `CHANGELOG.md`. Do NOT use for commit message wording (see commit agent) or for internal `refactor`/`chore`/`test`/`ci`/`build` commits that do not require a changelog entry.
Use when creating, editing, superseding, or reviewing Architecture Decision Records (ADRs) or Product Decision Records (PDRs) under `docs/decisions/` (including `docs/decisions/architecture/` and `docs/decisions/product/`); writing MADR-formatted decision documents; recording rationale for an architectural or upstream-driven choice; linking a decision to a TRaSH Guides upstream source; changing a decision's status (proposed, accepted, deprecated, superseded). Triggers on phrases like "write an ADR", "new PDR", "document this decision", "decision record", "add an architecture decision", or any edit to files matching `docs/decisions/**/*.md`. Do NOT use for general architecture documentation under `docs/architecture/`.
Use when weighing whether to extract a shared abstraction, base class, interface, or generic helper versus keeping code duplicated; evaluating DRY tradeoffs across parallel Sonarr and Radarr implementations, Refit or other code-generated API clients, OpenAPI/gRPC/GraphQL DTOs, or anti-corruption layers over distinct external systems; reviewing a PR that introduces a new shared abstraction spanning independent bounded contexts; considering unwinding a wrong abstraction back into duplicated copies. Triggers on phrases like "should I abstract this", "extract a base class", "these look duplicated", "DRY this up", "unify Sonarr and Radarr", "refactor to share", "rule of three", "wrong abstraction". Do NOT use for mechanical refactors within a single type or for trivial helper extraction inside one module.
Use when writing, editing, or reviewing Mapperly (`Riok.Mapperly`) mapper classes; adding or changing a `[Mapper]`-attributed partial class; configuring `RequiredMappingStrategy`, `[MapProperty]`, `[MapperIgnore]`, or other Mapperly attributes; mapping between nullable Refit/OpenAPI DTOs and non-nullable domain records; debugging null-handling in generated mapping code (positional records, `required init`, initializer defaults); investigating Mapperly diagnostics such as RMG001, RMG020, or RMG089; inspecting source-generated output under `obj/Debug/*/generated/Riok.Mapperly/`. Triggers on phrases like "add a Mapperly mapper", "Mapperly null handling", "DTO to domain mapping", "generated mapper", or edits to files ending in `*Mapper.cs` under `ServarrApi/`. Do NOT use for hand-written mapping code or AutoMapper.
Use when writing, editing, or reviewing C# code that uses System.Reactive (Rx.NET); working with `IObservable`, `IObserver`, `Subject`, `BehaviorSubject`, `ReplaySubject`, or `AsyncSubject`; composing operators like `Select`, `Where`, `Merge`, `Switch`, `Publish`, `RefCount`, `Catch`, `Retry`, `ObserveOn`, or `SubscribeOn`; managing subscription lifecycle with `CompositeDisposable`, `SerialDisposable`, or `DisposeWith`; testing time-dependent reactive code with `TestScheduler` from `Microsoft.Reactive.Testing`; designing hot vs cold observables or enforcing the Rx serial-notification contract. Triggers on phrases like "observable stream", "reactive pipeline", "Rx.NET", "subject leak", "OnNext on wrong thread", "test scheduler", or edits touching files that import `System.Reactive`. Do NOT use for plain `IEnumerable` LINQ, `IAsyncEnumerable`, or TPL `Task`-based async.