fix: clamp trim handle end position to timeline boundary

[muratclk]

Summary

Fixes #393 — the right-side trim handle could be dragged indefinitely past the end of the timeline.

Root cause: clampSpanToBounds in TimelineWrapper.tsx computed end = start + duration without capping it at totalMs. The sibling function clampToNeighbours does clamp end to totalMs, but it's only invoked when there's overlap with neighboring regions — so when no neighbor exists to the right, the handle was unconstrained.

Fix: Add Math.min(start + duration, totalMs) to ensure the end position never exceeds the video duration.

Test plan

• Open the video editor/trimmer interface
• Select a clip on the timeline
• Drag the right trim handle past the end of the timeline
• Verify the handle stops/snaps at the timeline boundary
• Verify left trim handle still works correctly
• Verify dragging the entire clip still clamps correctly

Summary by CodeRabbit

• Bug Fixes
  • Fixed video editor timeline behavior where selection spans could extend beyond the video's maximum duration. Selections are now clamped to the video's total time so range start/end values cannot exceed the video's end, preventing out-of-bounds ranges and improving timeline accuracy when trimming or selecting segments.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 6f6068ab-eeb0-4999-a0e0-a10412cdf3e8

📥 Commits

Reviewing files that changed from the base of the PR and between a72c3eb and c771bf8.

📒 Files selected for processing (1)

• src/components/video-editor/timeline/TimelineWrapper.tsx

🚧 Files skipped from review as they are similar to previous changes (1)

• src/components/video-editor/timeline/TimelineWrapper.tsx

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📝 Walkthrough

Walkthrough

Clamped timeline span end to never exceed totalMs: end is computed as Math.min(start + duration, totalMs) in clampSpanToBounds, ensuring returned { start, end } stays within the timeline's maximum duration.

Timeline Boundary Clamping

Layer / File(s)	Summary
Core clamp logic src/components/video-editor/timeline/TimelineWrapper.tsx	Changed clampSpanToBounds so end = Math.min(start + duration, totalMs) rather than start + duration, preventing span endpoints (e.g., right trim handle) from exceeding the timeline's total duration.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• siddharthvaddem/openscreen#243: also modifies timeline clamping logic to prevent visible spans from exceeding video duration.

Poem

a trim handle went rogue, stretching past the end,
lowkey cursed the edge — chaos to mend.
Math.min whispered gently, "that's where we stop,"
now the timeline breathes easy, no more crop.
small fix, calm UI — nightshift win, my friend.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title clearly and concisely describes the main fix: clamping trim handle end position to the timeline boundary.
Description check	✅ Passed	Description covers root cause, fix explanation, and test plan. Most template sections are present; Type of Change checkbox is unchecked but the fix is evident from context.
Linked Issues check	✅ Passed	The PR directly addresses issue #393 by implementing the exact fix needed: clamping end position with Math.min(start + duration, totalMs) to prevent handles from exceeding timeline boundaries.
Out of Scope Changes check	✅ Passed	Single-line change in clampSpanToBounds is scoped precisely to fix the trim handle boundary issue; no unrelated modifications detected.

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[selmamehdi48]

Thanks for this fix ❤️

[siddharthvaddem]

@muratclk linting and type checks failing