fix(collapsible): forward all Panel props through DefaultPanel

[mattrothenberg]

Summary

• Collapsible.DefaultPanel had a standalone props interface (children + className only), silently dropping props like keepMounted and hiddenUntilFound that Collapsible.Panel supports

• Extended CollapsibleDefaultPanelProps from BasePanelProps and spread remaining props through to the underlying Base UI Panel, bringing it to parity with Collapsible.Panel

• Added a keepMounted demo to the docs showing state preservation across collapse/expand

• Updated the DefaultPanel API reference table

• Reviews

• bonk has reviewed the change

• automated review not possible because: straightforward prop forwarding fix

• Tests

• Tests included/updated

• Additional testing not necessary because: typecheck passes, no existing component tests to update, and the change is a mechanical props passthrough

[mattrothenberg]

/bonk please approve

[ask-bonk]

/bonk approved

Clean mechanical fix that properly forwards Base UI Panel props through Collapsible.DefaultPanel. The interface now extends BasePanelProps and spreads remaining props to the underlying component, bringing it to parity with Collapsible.Panel.

• Code follows existing patterns ✅
• keepMounted demo added ✅
• API docs updated ✅
• Changeset included ✅

[ask-bonk]

Approved PR #468. The fix correctly extends CollapsibleDefaultPanelProps from BasePanelProps and forwards all remaining props to the underlying Base UI Panel component, resolving the issue where keepMounted and hiddenUntilFound were being silently dropped.

github run

[pkg-pr-new]

npm i https://pkg.pr.new/@cloudflare/kumo@468

commit: e919772

[github-actions]

Docs Preview

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Commit: dd4862c

[github-actions]

Visual Regression Report — 18 changed, 20 unchanged

18 screenshot(s) with visual changes:

Button / Icon Only

32 px (0.03%) changed

Before	After	Diff

Button / Loading State

6 px (0.01%) changed

Before	After	Diff

Dialog / Dialog With Actions

138 px (0.14%) changed

Before	After	Diff

Dialog / Dialog With Select

130 px (0.13%) changed

Before	After	Diff

Dialog / Dialog With Combobox

130 px (0.13%) changed

Before	After	Diff

Dialog / Dialog With Dropdown

130 px (0.13%) changed

Before	After	Diff

Dialog (Open)

0 px (0%) changed

Before	After	Diff

Select / Select Basic

485 px (0.48%) changed

Before	After	Diff

Select / Select Sizes

947 px (0.51%) changed

Before	After	Diff

Select / Select Without Label

105 px (0.1%) changed

Before	After	Diff

Select / Select With Field

852 px (0.72%) changed

Before	After	Diff

Select / Select Placeholder

418 px (0.41%) changed

Before	After	Diff

Select / Select With Tooltip

294 px (0.29%) changed

Before	After	Diff

Select / Select Custom Rendering

413 px (0.41%) changed

Before	After	Diff

Select / Select Disabled Options

765 px (0.75%) changed

Before	After	Diff

Select / Select Disabled Items

176 px (0.17%) changed

Before	After	Diff

Select / Select Grouped With Disabled

848 px (0.84%) changed

Before	After	Diff

Select (Open)

538 px (0%) changed

Before	After	Diff

20 screenshot(s) unchanged

• Button / Basic
• Button / Variant: Primary
• Button / Variant: Secondary
• Button / Variant: Ghost
• Button / Variant: Destructive
• Button / Variant: Outline
• Button / Variant: Secondary Destructive
• Button / Sizes
• Button / With Icon
• Button / Disabled State
• Button / Title
• Button / Link as Button
• Dialog / Dialog Basic
• Dialog / Dialog Alert
• Dialog / Dialog Confirmation
• Select / Select Loading
• Select / Select Multiple
• Select / Select Complex
• Select / Select Grouped
• Select / Select Long List

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Generated by Kumo Visual Regression