# Testing map

Purpose: authoritative map of what each test project/suite covers and how to run it. Read this
before adding tests, not just `docs/contributing.md` §8 (which now just points here).

## Test projects

| Project | Covers | Notes |
|---|---|---|
| `ErsatzTV.Tests` | API controllers + MediatR handlers | In-memory SQLite fixture: a shared `SqliteConnection("Data Source=:memory:;Foreign Keys=False")` kept open + `EnsureCreatedAsync()` (**not** full migration replay) + `PRAGMA foreign_keys=OFF`, then seed; a tiny `IDbContextFactory` wraps `new TvContext(...)`. 828 tests currently. |
| `ErsatzTV.Core.Tests` | Domain logic, scheduling, IPTV/XMLTV generation | References `ErsatzTV.Application` directly — there is no separate `Application.Tests` project. 542 tests + 1 skipped under `TZ=UTC` (the Block playout golden additionally skips under a non-UTC `TZ`; see Golden-file nets). |
| `ErsatzTV.Scanner.Tests` | Library scanning: scan handlers, folder scanners, NFO readers | Handler tests substitute the folder scanners + `ILibraryRepository` and assert the resulting repository writes (e.g. `ScanLocalLibraryHandlerTests` pins which `LastScan` levels a scan records — ersatztv#264). Fakes/`Testably` back the file-system-facing scanners. 1471 tests. Additionally contains `Core/FFmpeg/TranscodingTests` — `[Explicit]` + `[Combinatorial]`, so it never runs in CI or a plain `dotnet test` (it needs real ffmpeg/hardware) and contributes 0 to that count; run it by name when touching the transcoding pipeline. |
| `ErsatzTV.Architecture.Tests` | Layering rules via NetArchTest.eNhancedEdition | Core↛Infra/App/EF; FFmpeg↛all; App↛concrete providers. 5 tests. See `docs/contributing.md` §1. |
| `ErsatzTV.FFmpeg.Tests` | FFmpeg command construction | Build a pipeline, assert the exact rendered arg string (`PipelineBuilderBaseTests.cs`). |
| `web/` (vitest) | React SPA unit tests | 330 tests; run alongside typecheck + build (see below). |

## Golden-file nets

Three golden-file suites guard the highest-value, most-subtle output:

- **M3U**: `ErsatzTV.Core.Tests/Iptv/ChannelPlaylistGoldenTests.cs` (ersatztv#11) — env var `ETV_UPDATE_GOLDENS`
- **XMLTV**: `ChannelGuideGoldenTests` (ersatztv#28) — env var `ETV_UPDATE_GOLDENS`
- **Playout build**: `ErsatzTV.Core.Tests/Scheduling/Goldens/PlayoutBuildGoldenTests.cs` (ersatztv#163)
  — env var **`ETV_UPDATE_PLAYOUT_GOLDENS`** (deliberately separate from `ETV_UPDATE_GOLDENS` so
  regenerating one net can't silently rewrite the other). Snapshots the `PlayoutItem`s each builder
  produces over a pinned build window. Covers the **Classic** (`PlaybackOrder.Chronological`) and
  **Block** builders; **Sequential (YAML)** + **Scripted** are tracked in ersatztv#381. A third case,
  `Classic_clock_padded` (ersatztv#77), locks clock-boundary padding: a `FillerMode.Pad` +
  `PadToNearestMinute=15` PostRoll preset snaps content to `:15`, and the test both goldens the output and
  asserts every content item after the first starts on a quarter-hour. Its EPG counterpart is
  `ErsatzTV.Core.Tests/Channels/ChannelGuideProjectorClockPadTests.cs` (guide programmes stop on the padded
  boundary). The build reads
  no wall clock — time enters only via the caller-supplied `start` — so a pinned `start` is fully
  deterministic. Snapshots the raw `PlayoutItem.Start`/`Finish` (UTC), **not** the `*Offset` properties
  (those call `.ToLocalTime()` and would make the golden machine-TZ dependent). The **Block** case is
  TZ-sensitive by construction (`BlockPlayoutBuilder` maps template times via `TimeZoneInfo.Local`), so
  it is guarded with `Assume.That(TimeZoneInfo.Local.BaseUtcOffset == Zero)`: it runs under `TZ=UTC`
  (CI) and reports **inconclusive** (a graceful skip, not a failure) under any other TZ. A real TZ seam
  for the block builder is ersatztv#380's scope.

All three locate their golden files via `[CallerFilePath]`. A missing golden is a hard fail, not a
skip. Regenerate via `ETV_UPDATE_GOLDENS=1 dotnet test ...` (M3U/XMLTV) or
`ETV_UPDATE_PLAYOUT_GOLDENS=1 dotnet test ...` (playout build).

**Never set `ETV_UPDATE_GOLDENS` / `ETV_UPDATE_PLAYOUT_GOLDENS` in CI or from an agent.** A golden
diff during normal test runs means the code changed the output — regenerating to make the diff go
away hides the change instead of surfacing it. Only a human who has confirmed the change is
intentional should regenerate.

## Timezone independence

The suite is timezone-independent (ersatztv#24). When constructing test `PlayoutItem`s, always
set a real `Start` (e.g. `startState.CurrentTime.UtcDateTime`) — never rely on the default
`DateTime.MinValue`, which underflows `DateTimeOffset.MinValue` once a non-UTC local offset is
applied (`StartOffset` calls `ToLocalTime()`). CI runs in UTC; local runs may not.

## Running tests

Full .NET gate:

```bash
dotnet build ErsatzTV.sln
TZ=UTC dotnet test
```

CI adds `--blame-hang-timeout 2m` to catch hangs.

Fast subsets:

```bash
# single project
dotnet test ErsatzTV.Tests

# filtered
dotnet test ErsatzTV.Core.Tests --filter FullyQualifiedName~ChannelPlaylistGoldenTests
```

Web (`web/`):

```bash
npm test           # vitest
npm run typecheck  # tsc -b --pretty false
npm run lint       # eslint .
npm run build      # tsc -b && vite build
```

## Per-PR verification gate

Before opening a PR: build the solution, run `ErsatzTV.Tests` + `ErsatzTV.Core.Tests` (plus
`ErsatzTV.Scanner.Tests`, `ErsatzTV.Architecture.Tests` and `ErsatzTV.FFmpeg.Tests` if touched),
and run the web test/lint/typecheck/build steps above. All must be green. A golden-file diff or
an architecture-test failure is a hard stop — fix the code, don't regenerate/relax the test.

## See also

- `docs/ci-cd.md` — CI pipeline (test → migrations → build), versioning, dependency management.
- `docs/contributing.md` §1 — layering rules enforced by `ErsatzTV.Architecture.Tests`.
- `docs/contributing.md` §8 — short pointer back to this doc.