fix(button-group): preserve open trigger corners

[mattrothenberg]

Summary

• preserve the trailing rounded corners of a ButtonGroup overlay trigger while its menu is open
• flatten a control's end edge only when another button or link follows it
• add regression coverage for non-control siblings mounted by overlays

Before

After

Validation

• pnpm --filter @cloudflare/kumo exec vp test src/components/button-group/button-group.test.tsx

• pnpm --filter @cloudflare/kumo exec vp lint src/components/button-group

• verified the open-menu state in the local ButtonGroup docs using Chrome

• Reviews

• bonk has reviewed the change

• automated review not possible because: this is a focused CSS selector fix verified by regression test and local browser testing

• Tests

• Tests included/updated

• Automated tests not possible - manual testing has been completed as follows: not applicable

• Additional testing not necessary because: not applicable

[pkg-pr-new]

npm i https://pkg.pr.new/@cloudflare/kumo@809

commit: 2b971b6

[ask-bonk]

LGTM!

Review notes

• Confirmed the review target is cloudflare/kumo PR fix(button-group): preserve open trigger corners #809. I’ll inspect repository guidance, the PR diff, and existing review feedback before assessing the selector change and its regression coverage.
• The one-commit diff changes only ButtonGroup’s direct-control end-corner selector, adds a patch changeset, and adds a class-string regression assertion. There are no existing PR reviews or comments to avoid duplicating. I’m checking component nesting and overlay DOM behavior, including the retained wrapped-control selector.
• The documented split button renders DropdownMenu as a fragment-like root, so its trigger is a direct button in the group and its open portal can add a trailing non-control sibling. The revised :has(~ ...) selector correctly limits direct controls’ end-corner flattening to cases with a following direct control; I’m validating the generated selector and targeted test without modifying repository files.
• Full ButtonGroup, dropdown, tooltip, and documented split-button implementations were inspected. The end-edge selector applies only when a later sibling is a direct button or a, while the overlay trigger remains a direct control; this preserves the trailing corner when the portal adds a non-control sibling.
• Targeted test and lint commands could not run because pnpm is not installed in this runner. The worktree remains unmodified.

github run

[github-actions]

Visual Regression Report — 3 changed, 1 unchanged

3 screenshot(s) with visual changes:

Button Group / Basic

627 px (0.71%) changed

Before	After	Diff

Button Group / Button Group Split

714 px (0.81%) changed

Before	After	Diff

Button Group / Button Group Sizes

412 px (0.47%) changed

Before	After	Diff

1 screenshot(s) unchanged

• Button Group / Button Group Secondary

---

Generated by Kumo Visual Regression

[github-actions]

Visual contracts

Linux Chromium references exercised by the PR's visual-contracts job.

1 curated contract

truncating text trigger

[github-actions]

📐 Bundle Size

Consumer fixtures bundled against packages/kumo/dist (peers external, minified ESM).

Fixture	Raw	Gzip	Brotli
Button (root)	174.6 KB	49.9 KB	43.1 KB
Button (components/button)	174.5 KB	49.9 KB	43.1 KB
Button + Dialog + Select (root)	299.5 KB	85.8 KB	71.9 KB
Button + Dialog + Select (component subpaths)	299.5 KB	85.9 KB	71.9 KB
Chart (root)	247.0 KB	71.1 KB	60.9 KB
Chart (components/chart)	246.9 KB	71.1 KB	60.9 KB
Badge (components/badge)	44.7 KB	11.7 KB	10.0 KB
Flow (components/flow)	208.9 KB	58.3 KB	50.5 KB
Button (primitives/button)	12.2 KB	4.4 KB	3.9 KB
Primitives barrel	635.8 KB	176.9 KB	139.3 KB
Code highlighting (code)	2.08 MB	468.0 KB	349.3 KB

npm tarball: 544 files, 1.49 MB packed, 6.95 MB unpacked.

⚠️ 23 flagged files in tarball (tests / raw scripts)

• dist/blocks-source/resource-list/resource-list.test.tsx
• scripts/component-registry/cache.ts
• scripts/component-registry/discovery.ts
• scripts/component-registry/example-cleanup.ts
• scripts/component-registry/index.test.ts
• scripts/component-registry/index.ts
• scripts/component-registry/markdown-generator.ts
• scripts/component-registry/metadata.ts
• scripts/component-registry/props-filter.ts
• scripts/component-registry/schema-generator.ts
• scripts/component-registry/sub-components.ts
• scripts/component-registry/types.ts
• scripts/component-registry/utils.ts
• scripts/component-registry/variant-parser.ts
• scripts/css-build.ts
• scripts/generate-globe-land-mask.mjs
• scripts/generate-primitives.ts
• scripts/theme-generator/config.ts
• scripts/theme-generator/generate-css.test.ts
• scripts/theme-generator/generate-css.ts
• scripts/theme-generator/index.ts
• scripts/theme-generator/migrate.ts
• scripts/theme-generator/types.ts

Report-only: no size thresholds are enforced yet.

Commit: 2b971b62

[cloudflare-workers-and-pages]

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