fix(components): [virtual-list] incorrect scroll boundary check by rzzf · Pull Request #23289 · element-plus/element-plus

rzzf · 2026-01-03T09:01:43Z

After rapidly scrolling upward with a mouse or trackpad, offset becomes negative. When scrolling downward slowly afterward, both offset and offset + newOffset remain negative, causing the boundary check to keep failing and preventing the list from scrolling down.

This issue doesn’t seem easy to reproduce in the playground. It may be better to verify it locally.

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20260103-170343.mp4

Summary by CodeRabbit

Bug Fixes
- Enhanced virtual list scroll behavior to allow smoother movement in additional scenarios when approaching edge boundaries.

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github-actions · 2026-01-03T09:01:51Z

coderabbitai · 2026-01-03T09:01:54Z

📝 Walkthrough

Walkthrough

The wheel handler's edge-detection logic was changed: the early-return now triggers based on the next offset alone reaching an edge, instead of requiring both the current and next offsets to reach an edge.

Changes

Cohort / File(s)	Summary
Wheel Handler Edge Detection `packages/components/virtual-list/src/hooks/use-wheel.ts`	Modified edge-check logic: early-return condition now checks only the next offset reaching an edge rather than requiring both current and next offsets.

Sequence Diagram(s)

(omitted — change is localized and does not introduce multi-component sequential flow)

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Possibly related PRs

improvement(components): [virtual-list] preventDefault only when the scroll directions match #22989 — Modifies wheel-event handling in the same file (use-wheel.ts), changing when wheel events are suppressed/prevented.

Suggested labels

CommitMessage::Unqualified

Suggested reviewers

Dsaquel
btea

Poem

🐰 I nudge the wheel with careful paws tonight,
One step ahead I see the edge in sight.
No double-check, just the next hop's cue,
I hop, the list scrolls—smooth and new! ✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: fixing an incorrect scroll boundary check in the virtual-list component.
Description check	✅ Passed	The description adequately explains the bug, reproduction steps, and includes a working example link, but does not follow the repository's pull request template structure.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between 4b04769 and 23d10b0.

📒 Files selected for processing (1)

packages/components/virtual-list/src/hooks/use-wheel.ts

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pkg-pr-new · 2026-01-03T09:03:32Z

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pnpm add https://pkg.pr.new/element-plus/element-plus@23289

npm i https://pkg.pr.new/element-plus/element-plus@23289

yarn add https://pkg.pr.new/element-plus/[email protected]

commit: 23d10b0

github-actions · 2026-01-03T09:04:43Z

Size Change: -22 B (0%)

Total Size: 1.6 MB

Filename	Size	Change
`./dist/element-plus/dist/index.full.js`	459 kB	-6 B (0%)
`./dist/element-plus/dist/index.full.min.js`	323 kB	-6 B (0%)
`./dist/element-plus/dist/index.full.min.mjs`	318 kB	-5 B (0%)
`./dist/element-plus/dist/index.full.mjs`	450 kB	-5 B (0%)

ℹ️ View Unchanged

Filename	Size
`./dist/element-plus/dist/index.css`	46.7 kB

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coderabbitai

Actionable comments posted: 0

🧹 Nitpick comments (1)

packages/components/virtual-list/src/hooks/use-wheel.ts (1)
22-27: Consider adding clarifying comment for edge detection logic.

The hasReachedEdge function's behavior might benefit from a brief comment explaining that it returns true only when attempting to scroll further in the direction of an already-reached edge, not when scrolling away from it. This would make the intent clearer for future maintainers.
Suggested documentation
 const hasReachedEdge = (offset: number) => {
+  // Returns true only when trying to scroll further past an edge:
+  // - negative offset while at start edge, or positive offset while at end edge
   const edgeReached =
     (offset < 0 && atStartEdge.value) || (offset > 0 && atEndEdge.value)

   return edgeReached
 }

📜 Review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 4b04769 and 23d10b0.

📒 Files selected for processing (1)

packages/components/virtual-list/src/hooks/use-wheel.ts

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🔇 Additional comments (1)

packages/components/virtual-list/src/hooks/use-wheel.ts (1)

41-41: Correct fix for the edge-detection bug.

The change from checking offset + newOffset to checking only newOffset correctly resolves the issue where accumulated negative offset prevented scrolling away from an edge. The new logic properly distinguishes between:

Scrolling further into an edge (blocked): newOffset direction matches the edge we've reached

Scrolling away from an edge (allowed): newOffset direction is opposite to the edge

This prevents the scenario where rapid scrolling accumulates a large offset before the frame executes, causing the old offset + newOffset check to incorrectly block scrolling in the opposite direction.

github-actions · 2026-01-03T09:05:48Z

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	85.34%	17794 / 20849
🔵	Statements	84.14%	18622 / 22132
🔵	Functions	83.82%	4793 / 5718
🔵	Branches	73.57%	10170 / 13822

File Coverage

File	Stmts	% Branch	% Funcs	% Lines	Uncovered Lines
Changed Files
packages/components/virtual-list/src/hooks/use-wheel.ts	23.8%	0%	25%	25%	24, 26, 30, 32, 34-37, 35-36, 39, 41, 41, 43, 45-47, 46, 49-52, 50-51

Generated in workflow #510

github-actions · 2026-01-03T09:10:06Z

🧪 Playground Preview: https://element-plus.run/?pr=23289
Please comment the example via this playground if needed.

rzzf · 2026-01-03T09:12:11Z

@coderabbitai summary

coderabbitai · 2026-01-03T09:12:19Z

✅ Actions performed

Summary regeneration triggered.

github-actions · 2026-01-04T06:35:20Z

@rzzf Thanks for your contribution! ❤️

fix(components): [virtual-list] incorrect scroll boundary check

23d10b0

pull-request-triage Bot assigned rzzf Jan 3, 2026

coderabbitai Bot reviewed Jan 3, 2026

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Dsaquel approved these changes Jan 3, 2026

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btea approved these changes Jan 4, 2026

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btea merged commit 71e5216 into dev Jan 4, 2026
21 checks passed

btea deleted the fix/virtual-list-reached-edge branch January 4, 2026 06:35

coderabbitai Bot mentioned this pull request Jan 5, 2026

fix(components): [virtual-list] incorrect scroll boundary check #20766

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3 tasks

element-bot mentioned this pull request Jan 9, 2026

D2M #23355

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coderabbitai Bot mentioned this pull request Jan 9, 2026

chore: Update changelog 2.13.1 #23357

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coderabbitai Bot mentioned this pull request Feb 20, 2026

fix(components): [table-v2] navigation back triggered by trackpad scrolling #23673

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coderabbitai Bot mentioned this pull request Mar 15, 2026

feat(components): [select/select-v2] add end-reached event #23806

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3 tasks

coderabbitai Bot mentioned this pull request Jun 2, 2026

feat(components): [transfer] add virtual scroll support #24367

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