Web Shell mention icon chips verification

Test groups

Built-in mention chips

Verify that accepting an extension, file, or MCP @ mention inserts the original serialized text into the editor and attaches an inline composer tag over the inserted reference. The visible result should be an inline chip with the built-in icon instead of plain @ext:..., @mcp:..., or file reference text.

Custom mention chips

Register an atProvider whose item provides composerTag.kind = 'table' and pass composerTagIcons={{ table: '<icon-url>' }} to WebShell. Accepting the item should insert the provider's insertText and render an inline chip using the registered table icon.

Regression coverage

Verify custom icon lookup ignores inherited object properties, built-in icons still resolve without a custom registry, and icon URLs are escaped before being written into CSS custom properties.

Local verification

• cd packages/web-shell && npx vitest run client/hooks/useComposerCore.test.ts client/hooks/useAtMentionMenu.test.tsx client/components/composerTagIcons.test.ts client/utils/cssUrlVar.test.ts
• Result: passed, 4 files and 80 tests.
• npx eslint packages/web-shell/client/customization.tsx packages/web-shell/client/components/composerTagIcons.ts packages/web-shell/client/components/composerTagIcons.test.ts packages/web-shell/client/components/ChatEditor.tsx packages/web-shell/client/hooks/useAtMentionMenu.ts packages/web-shell/client/hooks/useAtMentionMenu.test.tsx packages/web-shell/client/hooks/useComposerCore.ts packages/web-shell/client/hooks/useComposerCore.test.ts packages/web-shell/client/index.ts packages/web-shell/client/App.tsx packages/web-shell/client/utils/cssUrlVar.ts packages/web-shell/client/utils/cssUrlVar.test.ts
• Result: passed.
• npm run build --workspace=packages/web-shell
• Result: passed with existing Vite large chunk warnings.

Not run

Manual browser screenshots were not captured in this environment. The behavior is covered at the hook and rendering helper boundaries, and the package build validates the web-shell bundle.

Built-in SVG data URI regression (2026-07-16)

Baseline

• Global qwen --version: 0.18.5-preview.0.
• The pre-fix DOM matrix resolved all four built-in icons to data:image/svg+xml URLs, then rendered zero icon mask nodes in inline composer tags, top composer tags, and submitted user-message tags.

Verification

• Accepting an extension from the @ menu still inserts an inline tag with kind: 'extension'.
• Inline composer tags, top composer tags, and submitted user-message tags each render four icon mask nodes for extension, file, MCP, and skill references.
• Arbitrary SVG data URIs and javascript: custom icon URLs remain absent from the DOM on all three surfaces.
• Focused WebShell result: 5 files and 128 tests passed, including the extension @ acceptance path.
• Full repository build passed after installing the dependency set declared by the existing lockfile; full repository typecheck passed.