Activating #253's `Version` as an `IsConcurrencyToken` made EF guard every
UPDATE *and DELETE* of a versioned root with `WHERE Version=@orig`, so any
writer outside the If-Match contract that saves via plain `SaveChangesAsync`
throws an unhandled `DbUpdateConcurrencyException`->500 when a replace-all
editor bumps the row in its narrow load->save window (ordinary two-tab UI).
A completeness sweep (grep every `Version` bumper + every root delete, not
just the handlers PR3's close note named) found 17 exposed writers, all now
routed through `ConcurrencyExtensions.SaveChangesForcingVersion` (Phase-1
force-write: adopt the stored token and retry; rethrow only on genuine
row-deletion):
- 9 versioned-root delete handlers (a delete has no ETag to rotate -> force
only, no bump)
- UpdateProgramScheduleHandler (bumps then saved plainly - the ProgramSchedule
case PR3 only suspected; its post-commit query/enqueue also moved to
CancellationToken.None per section 7b)
- 7 item add/remove bumpers PR2 left on plain save:
Add/DeleteProgramScheduleItem + Add{Items,Movie,Show,Season,Episode}ToPlaylist
Force-write (not 412) is correct: these endpoints take no If-Match, so an
unconditional delete/edit should win. No API contract change (no new response
codes) -> no OpenAPI regen.
Still deferred to #197 (cross-editor ETag rotation only, not a 500): the
non-bumping config siblings + the scanner-shared Add*ToCollection family.
Tests: RootWriterForceVersionTests races a bump *through the handler* via a
pre-tracked context (non-vacuous - reverting a handler to plain save fails the
test, verified) for the Option-delete / Either-delete / bump+update shapes,
plus the genuine-conflict rethrow branch and an explicit negative control
proving the plain-save path throws. Full ErsatzTV.Tests green (1482).
Also strips a pre-existing UTF-8 BOM from the touched handlers to satisfy the
.editorconfig `charset=utf-8` rule the pre-commit format hook enforces.
Docs: api-conventions section 7a (fan-out completeness) + decisions.md entry.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Backend mutation-hardening cluster from the 2026-07-11 mutation-safety audit
sweep (adversarial-reviewer #22/#23), the parallel-safe backend-isolated slice.
audit#22 F4 — standardize post-commit enqueues on CancellationToken.None:
20 command handlers under MediaCollections/, ProgramSchedules/, Playouts/,
Channels/ threaded the request cancellationToken into work that runs AFTER
SaveChangesAsync commits (WriteAsync rebuild/refresh enqueues, mediator.Publish,
reindex, cache Refresh, and post-commit lookups that gate an enqueue). A late
client-disconnect then turns an already-durable commit into a thrown request AND
drops the side effect. Generalizes the #251 deco-handler fix. Excludes
BuildPlayoutHandler (worker/background token, not a client-disconnect token),
the config/FFmpeg multi-upsert handlers (partial-commit case, separate
follow-up), and response-projection reloads (correctly keep the request token).
audit#22 F2 — DeleteChannelHandler/DeletePlayoutHandler now delete the channel
guide {number}.xml through IFileSystem.File.Delete (observable under
MockFileSystem) and BEFORE the commit (a post-commit delete orphans the xml on a
crash; the xml is regenerable on demand, so pre-commit delete is the safe order).
audit#23 F4 — ReplacePlayoutAlternateScheduleItemsHandler rejects an empty item
list in the handler (not only the controller pre-guard) so a direct caller can't
trip the Max()-on-empty crash.
Docs: api-conventions.md §7a (post-commit token convention + boundaries),
decisions.md entry (rationale, sweep scope, #253 PR2-4 coordination note).
Tests: guide-cache-delete-through-FS for both delete handlers, empty-list guard.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
timothyandClaude Opus 4.8