[IzumiSy]

Motivation

Navigation labels sometimes need more room, but the sidebar currently supports only expanding and collapsing. Make resizing a standard desktop interaction, including reopening a collapsed sidebar and continuing to resize without releasing the pointer.

Design Decision

Default-enabled desktop behavior

Resizing is enabled by default in <SidebarLayout /> and <GlobalHeaderLayout />; apps can opt out with resizable={false}. Mobile/tablet behavior remains unchanged. Only the central grip starts resizing, and the grip remains available when collapsed. Pointer gestures use position-based resistance and early collapse snapping rather than delayed mouse tracking or a jump to the default width. Click and keyboard expansion still restore 256px.

Live pixels outside React state

Keep pointer capture and interaction decisions in JavaScript, but apply live width and position through CSS custom properties with calc() and max(). React commits widths only at mode changes and gesture completion, avoiding per-move rerenders and Context updates while keeping ARIA values current. Content continues resizing live, so layout work remains; this is not a compositor-only animation.

Summary

• Add default-enabled desktop resize/expand handles with continuous dragging, 192–480px expanded bounds, keyboard controls, and an explicit opt-out.
• Cover defaults, opt-out, resistance, early collapse, pointer cleanup, live ARIA, CSS geometry, and the absence of per-move React renders with unit and browser tests.
• Refresh browser dependency prebundles on each run so style contracts exercise the newly built package rather than stale JavaScript.
• Update authored documentation and generated outputs, and include a minor changeset.

[github-actions]

Code Metrics Report

	main (b8ead52)	#659 (8e49999)	+/-
Coverage	89.5%	89.7%	+0.2%
Test Execution Time	3m20s	2m15s	-1m5s

Details

  |                     | main (b8ead52) | #659 (8e49999) |  +/-  |
  |---------------------|----------------|----------------|-------|
+ | Coverage            |          89.5% |          89.7% | +0.2% |
  |   Files             |            236 |            237 |    +1 |
  |   Lines             |           7517 |           7616 |   +99 |
+ |   Covered           |           6732 |           6837 |  +105 |
+ | Test Execution Time |          3m20s |          2m15s | -1m5s |

Code coverage of files in pull request scope (82.2% → 93.0%, patch 99.0%)

Files	Coverage	+/-	Patch Coverage	Status
packages/core/src/components/sidebar/global-header-layout.tsx	100.0%	0.0%	100.0%	modified
packages/core/src/components/sidebar/primitives.tsx	86.7%	+8.0%	100.0%	modified
packages/core/src/components/sidebar/sidebar-layout.tsx	100.0%	0.0%	100.0%	modified
packages/core/src/components/sidebar/sidebar-resize-handle.tsx	98.9%	+98.9%	98.9%	added

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Reported by octocov