Copilot + CodeRabbit review findings:
- React.memo ChapterTicks and ChapterList (project guideline: hot-path
components must use React.memo to cut redraw work during control
updates).
- chapterNameAt now sorts the chapter array once instead of twice per
call. The previous version went through currentChapterIndex
(chapterStartsMs + sort) then sortedChapters (sort again). Runs on
every playback tick, so the duplicate work added up.
- Import getUserLibraryApi from the public barrel
(@jellyfin/sdk/lib/utils/api) instead of the deep internal path
(@jellyfin/sdk/lib/utils/api/user-library-api) to match the rest of
the codebase and avoid coupling to SDK file layout.
TrickplayBubble polish:
- Sit just above the slider (bottom: 0) so the bubble no longer overlaps
the progress bar.
- Move the chapter-name + timestamp overlay to the bottom-left of the
preview frame, smaller font, in front of the surrounding overlays
(zIndex + elevation).
BottomControls cleanup:
- Drop dev-only "pick one to test" comment in favour of a one-line note
on TICK_HEIGHT.
- Inline scrubMs into its useMemo callback so the scrub-chapter-name
lookup only recomputes while a slide is active.
Adds dependency-free helpers in utils/chapters.ts for working with
Jellyfin chapter markers:
- chapterMarkers(chapters, durationMs): markers within range, with
precomputed percent for slider overlays.
- chapterStartsMs(chapters): sorted start positions in ms (skips
entries without StartPositionTicks).
- currentChapterIndex(positionMs, chapters): active chapter index
for the live playback position (-1 if before the first chapter).
- chapterNameAt(positionMs, chapters): the active chapter name, or
null if missing/unnamed.
- sortedChapters(chapters): chapter entries paired with ms start.
- formatChapterTime(positionMs): m:ss or h:mm:ss label.
All helpers tolerate null/undefined/empty inputs.
17 unit tests under bun test cover sort order, boundary positions,
missing fields, and out-of-range inputs.
