feat(timeline): scroll position lives in url by chiptus · Pull Request #201 · chiptus/UpLine

chiptus · 2026-07-14T18:34:12Z

Stacked on the #191 branch (claude/188-191-timeline-geometry) / PR. Adds a scrollTo search param that captures the moment centered in the Timeline viewport, with a pure precedence function deciding the mount position and a dedicated hook owning one-way scroll<->URL sync.

Closes #192

Verification

Load the timeline with no scrollTo in the URL; scroll the horizontal timeline and confirm scrollTo appears in the URL (~300ms after scrolling stops), rounded to 5 minutes, via history replace (back doesn't land on an intermediate scroll state).
Load a timeline URL with scrollTo set; confirm the viewport centers on that moment on mount.
Change the day filter with no scrollTo present; confirm the viewport centers on that day's start.
Scroll the timeline and confirm the day/time/stage filters and rendered schedule do not recompute (no flicker/reflow) purely from the scrollTo write.
Run pnpm vitest run — includes new unit tests for resolveTimelineMountMoment and roundToNearestMinutes in src/lib/timelineMountMoment.test.ts.
New Playwright spec tests/e2e/timeline-scroll.spec.ts covers scroll-to-URL writing, mount centering, and back/reload restoring the viewport (runs in CI, not run locally in this environment).

Generated by Claude Code

qodo-code-review · 2026-07-14T18:34:16Z

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vercel · 2026-07-14T18:34:18Z

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Project	Deployment	Actions	Updated (UTC)
upline	Ready	Preview, Comment	Jul 18, 2026 2:54pm

Copilot

Pull request overview

Adds URL-backed scroll position for the horizontal schedule timeline by introducing a scrollTo search param, a pure mount-moment precedence resolver, and a dedicated hook to own one-way scroll ↔ URL synchronization. This builds on the timeline geometry work by centralizing time↔pixel mapping helpers and adding unit/e2e coverage around the new behavior.

Changes:

Introduces scrollTo URL state with debounced history-replace writes and mount-time centering via useTimelineScrollSync.
Adds pure utilities (resolveTimelineMountMoment, roundToNearestMinutes, timeToOffset, offsetToTime) with new unit tests.
Updates timeline rendering to consume shared geometry functions and adds Playwright coverage for scrollTo behavior.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/e2e/timeline-scroll.spec.ts	New e2e coverage for debounced URL writes, mount centering, and back/reload restoration.
src/pages/EditionView/tabs/ScheduleTab/horizontal/TimeScale.tsx	Switches time axis positioning to shared `timeToOffset` mapping.
src/pages/EditionView/tabs/ScheduleTab/horizontal/TimelineContainer.tsx	Wires in `useTimelineScrollSync` and adds a test id for the scroll container.
src/lib/timelineMountMoment.ts	Adds pure mount precedence resolver + rounding helper for coarse `scrollTo` values.
src/lib/timelineMountMoment.test.ts	Unit tests for mount precedence and rounding behavior.
src/lib/timelineCalculator.ts	Adds canonical time↔pixel conversion helpers and applies them to set positioning/width and total width.
src/lib/timelineCalculator.test.ts	Unit tests for geometry mappings and key timeline-boundary behaviors.
src/lib/searchSchemas.ts	Extends timeline search schema to accept optional `scrollTo`.
src/hooks/useTimelineUrlState.ts	Uses narrowed `select` + structural sharing to prevent scrollTo writes from invalidating filter state.
src/hooks/useTimelineScrollSync.ts	New hook implementing one-way mount centering and debounced scroll→URL sync.

Add a scrollTo search param that captures the moment centered in the Timeline viewport. A pure resolveTimelineMountMoment precedence function (scrollTo -> day filter -> festival start) decides where to center on mount; useTimelineScrollSync owns that one-time centering plus debounced (~300ms), 5-minute-rounded, history-replace writes on user scroll. useTimelineUrlState now selects its filter params with structural sharing so scrollTo writes don't recompute the filtered schedule. Closes #192 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

Position-based suppression of programmatic scroll events (a browser may fire more than one per scrollLeft write), and the back-restore e2e half now skips explicitly instead of silently passing when no set link is rendered. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

Also drops a redundant schema comment, per review. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

The browser clamps scrollLeft to the scrollable range, so the suppression ref must record the read-back value, not the requested target, for the scroll handler to recognize the mount event. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

The rebase onto main brought in #199's removal of the view search param; the select still read it, failing typecheck. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

Extracts the repeated clock-install/goto/skip-if-hidden block into openTimeline(), and turns the set-detail-link skip in the back-navigation test into an assertion so missing seed data fails loudly instead of silently dropping that acceptance criterion's coverage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

Addresses review feedback — the invariant is already explained inline by the structuralSharing thread on this PR.

Turns on defaultStructuralSharing router-wide instead of opting in per-hook, so any future select-based hook gets stable identities by default rather than needing to remember structuralSharing: true.

This structuralSharing addition belonged to the earlier scrollTo URL-state work (#192/#201), not the day-jump toolbar; it was leftover diff noise picked up before the branch was rebased onto main.

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chiptus commented Jul 15, 2026

View reviewed changes

Comment thread src/hooks/useTimelineUrlState.ts Outdated

Comment thread src/lib/searchSchemas.ts Outdated

Comment thread tests/e2e/timeline-scroll.spec.ts Outdated

Base automatically changed from claude/188-191-timeline-geometry to main July 15, 2026 19:31

Copilot AI review requested due to automatic review settings July 15, 2026 19:33

Copilot started reviewing on behalf of chiptus July 15, 2026 19:33 View session

vercel Bot deployed to Preview July 15, 2026 19:33 View deployment

Copilot AI reviewed Jul 15, 2026

View reviewed changes

Comment thread src/hooks/useTimelineScrollSync.ts

Comment thread src/hooks/useTimelineScrollSync.ts

Comment thread src/hooks/useTimelineScrollSync.ts

vercel Bot deployed to Preview July 15, 2026 19:43 View deployment

claude added 4 commits July 16, 2026 14:17

test(timeline): drive debounce waits with playwright fake clock

162493c

Also drops a redundant schema comment, per review. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

chiptus force-pushed the claude/188-192-scrollto-url-state branch from 5fcab7c to acf2265 Compare July 16, 2026 14:17

vercel Bot deployed to Preview July 16, 2026 14:18 View deployment

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chiptus mentioned this pull request Jul 18, 2026

fix(timeline): hour-axis geometry is 20px out of sync with set/date-label positioning #207

Open

vercel Bot deployed to Preview July 18, 2026 11:56 View deployment

chiptus commented Jul 18, 2026

View reviewed changes

Comment thread src/hooks/useTimelineScrollSync.ts

refactor(timeline): move scroll handler below effect wiring

1e9b23c

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AziTqr3f12fxALYD6jhrW8

vercel Bot deployed to Preview July 18, 2026 12:28 View deployment

chiptus commented Jul 18, 2026

View reviewed changes

Comment thread src/hooks/useTimelineScrollSync.ts

chiptus commented Jul 18, 2026

View reviewed changes

Comment thread src/hooks/useTimelineUrlState.ts Outdated

refactor(timeline): drop select/structuralSharing comment

2f346ac

Addresses review feedback — the invariant is already explained inline by the structuralSharing thread on this PR.

vercel Bot deployed to Preview July 18, 2026 14:47 View deployment

refactor(router): default structural sharing on for all useSearch/select

59eae62

Turns on defaultStructuralSharing router-wide instead of opting in per-hook, so any future select-based hook gets stable identities by default rather than needing to remember structuralSharing: true.

vercel Bot deployed to Preview July 18, 2026 14:54 View deployment

chiptus merged commit 95b94d7 into main Jul 18, 2026
10 checks passed

chiptus deleted the claude/188-192-scrollto-url-state branch July 18, 2026 16:55

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feat(timeline): scroll position lives in url#201

feat(timeline): scroll position lives in url#201
chiptus merged 9 commits into
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claude/188-192-scrollto-url-state

chiptus commented Jul 14, 2026

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chiptus commented Jul 14, 2026

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Pull request overview

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vercel Bot commented Jul 14, 2026 •

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