Moves four self-contained helpers into src/utils/, each with co-located
characterization tests. playerStore re-exports them for the ~30 existing
call sites; Phase E will migrate those imports.
- shuffleArray (Fisher-Yates, generic)
- resolveReplayGainDb (track/album/auto mode resolution)
- songToTrack (Subsonic -> Track shape)
- buildInfiniteQueueCandidates (Instant-Mix top-up source)
playerStore.ts: 3732 -> 3618 LOC (-114).
Adds 22 new tests on top of the existing 7 _on* / stopPreview ones.
startPreview happy path: invokes audio_preview_play with the configured
args (id, url, durationSec, startSec, volume) and stores the previewing
track + duration + reset elapsed / audioStarted. Short tracks
(duration <= previewDuration * 1.5) start at 0; longer tracks seek to
duration * trackPreviewStartRatio. Camel-case IPC keys pinned
(startSec / durationSec, not snake_case -- CLAUDE.md gotcha).
Cross-store guard tests: no-op when previews globally disabled, no-op
when disabled at the calling location, no-op while a host or guest is
inside any Orbit phase (active / joining / starting), falls through to
play when role is null (no session).
Same-id re-click: treats it as a stop -- audio_preview_stop fires,
audio_preview_play does not.
Failure path: engine invoke rejects -> store state rolls back
(previewingId / previewingTrack / audioStarted) and the error propagates
to the caller.
Loudness pre-attenuation folding: with normalizationEngine=loudness +
loudnessPreAnalysisAttenuationDb=-6 dB, volume is multiplied by
10^(-6/20). normalizationEngine=off keeps volume verbatim. Positive
pre-attenuation values are pulled to 0 by the Math.min(0, ...) guard.
Main-player volume sync side-effect (module-level
usePlayerStore.subscribe): pings audio_preview_set_volume when volume
changes during a preview, skips when no preview is active, skips when
the new value equals the prior value (subscription guard).
previewStore.ts coverage 33% -> 100% lines. Added to the hot-path gate.
Plus the typed `OrbitRole` is `'host' | 'guest'` (null when no session),
not 'idle' as a string -- minor type-correctness alignment.
subsonic.contract.test.ts (21): parseSubsonicEntityStarRating (userRating
first then rating fallback, numeric-string coercion, undefined for null /
NaN / non-numeric), libraryFilterParams (empty without active server, empty
on "all" filter, returns musicFolderId on specific filter), getClient
(throws without a server, returns baseUrl + auth params, rotates token + salt
across calls), coverArtCacheKey (serverId:cover:id:size shape, "_" fallback
without active server, no ephemeral salt embedded -- stays cacheable),
buildStreamUrl (URL shape + Subsonic auth params: id u t s v=1.16.1
c=psysonic/* f=json, rotates t/s across calls so Rust matches by id, special
character ids encoded once not twice), buildCoverArtUrl (default size=256),
buildDownloadUrl (download.view path), trailing-slash + scheme handling on
base URL.
resolvePlaybackUrl.test.ts (15): precedence offline > hot-cache > stream
(first priority wins even when later sources also have the track), forwards
trackId + serverId to both stores. getPlaybackSourceKind for offline / hot
/ stream / engine-preload-hint cases. streamUrlTrackId parser (id from
stream.view query, null for non-stream URLs / no query / missing id, decodes
URL-encoded ids, manual-query fallback for relative paths).
copyEntityShareLink.test.ts (5): writes a psysonic2-prefixed payload that
round-trips, returns false without an active server, returns false on
empty / whitespace id, trims surrounding whitespace before encoding,
propagates clipboard-failure return.
Gate broadens with src/utils/resolvePlaybackUrl.ts (95.8 %) +
src/utils/copyEntityShareLink.ts (100 %). subsonic.ts at 12.7 % stays out
-- the URL-builder + parser surface this PR covers is the structural part;
the async API endpoints need axios mocking, deferred to a follow-up.
authStore.ts (79 %) and playerStore.ts (40 %) deferred-list comments
updated to reflect F2 + F1 actuals.
Frank Stellmacher