This matrix is the release gate for the 4.9.x stabilization cycle. Every release candidate from 4.8.8 onward should be checked against these scenarios before promoting the runtime file.
| Scenario |
What to verify |
| Mobile narrow |
Hero, controls, progress, and volume stay aligned with no horizontal overflow. |
| Tablet landscape |
Split hero remains balanced and media controls feel centered, not detached. |
| Tablet portrait |
Rail, hero, and bottom spacing remain readable and stable. |
| Desktop wide |
No stretched controls, broken gradients, or empty dead zones. |
| RTL |
Titles, rails, queue, and sliders stay visually correct and input-safe. |
| Light theme |
Contrast, text legibility, slider track visibility, and button outlines remain premium. |
| Dark theme |
Hero hierarchy stays clear and background effects do not muddy the artwork. |
| Idle state |
Empty state remains elegant with no broken art placeholders or stale metadata. |
| Playing state |
Progress, play state, active buttons, and artwork update without visual jumps. |
| Long metadata |
Long title / artist / album do not break layout or collide with action clusters. |
| Missing artwork |
Fallback artwork, aura, and title layout remain stable. |
| Unavailable player |
Card fails gracefully with usable status messaging and no JS crashes. |
| Interaction |
What to verify |
| Play / pause |
State, icon, and pulse visuals update without double-render artifacts. |
| Previous / next |
Controls react immediately and metadata/artwork stay in sync. |
| Progress seek |
Drag, click, and release update the visual state correctly. |
| Volume slider |
Thumb, fill, mute state, and percentage remain consistent across themes. |
| Theme toggle |
No stale colors, unreadable text, or broken translucency after toggling. |
| Player switch |
Selected player chip, metadata, and queue all switch together. |
5.1.5 is blocked by any known P0 or P1 bug in the matrix above.- Cosmetic
P3 issues may ship only if they are documented and non-regressive.
- Any regression found in one viewport/theme combination must be retested across the rest of the matrix after the fix lands.