Waves Browser WBP-05A Accessibility Evidence

Status: accepted corrective/evidence follow-up Captured: 2026-07-26 Owner lane: browser, qa

Scope

WBP-05A closes the additive accessibility gap found after WBP-05; it does not reopen or rewrite the completed baseline. The change remains browser-local and does not add a browser-authored WML semantic tree. Engine-derived card/action semantic adaptation remains WBP-09 scope.

The shell now owns one visually hidden role="status", aria-live="polite", aria-atomic="true" announcement channel outside collapsible content. Navigation loading and failure status changes write that channel once. The visible status panel and recovery toast retain their messages and tone without acting as parallel live regions. Toast-only host events, including deterministic script dialogs and failures, reuse the same channel.

Automated Evidence

browser/frontend/src/app/navigation-announcement.test.ts observes the live-region mutation boundary directly and proves one write for each deterministic loading and failure state change. It also proves that the visible status and toast remain populated and that the mounted shell exposes exactly one live-announcement channel.

pnpm --dir browser/frontend test:accessibility:rendered builds browser-story.html for production, loads the real WaveNav WASM engine with deterministic local fixtures, and runs headless Chromium at both configured Tauri window sizes. Effective 200 percent browser zoom is modeled as a half-sized CSS viewport with deviceScaleFactor: 2, retaining screenshots at the physical window dimensions:

Window	Physical pixels	CSS viewport at 200%	Horizontal overflow	Rendered axe violations
Default	1024 by 768	512 by 384	none	0
Minimum	880 by 640	440 by 320	none	0

The rendered check opens every host disclosure, runs the full axe ruleset (including 50 passing color-contrast nodes at each size), and independently verifies every visible enabled host target is at least 24 by 24 CSS pixels and is not horizontally clipped. Keyboard traversal asserts each of 28 host tab stops matches :focus-visible and has a 2-pixel black outline, 2-pixel offset, and white outer separation ring. Reduced motion is enabled during capture.

Machine-readable measurements, exact target boxes, focus styles, environment, and the zero- violation results are in evidence/wbp-05a/rendered-accessibility.json.

Default window at 200 percent with Reload focus visible

Minimum window at 200 percent with Reload focus visible

Reproduce

From the repository root with Node.js 22.22.1, pnpm 10.23.0, wasm-pack, and Playwright Chromium available:

cd engine-wasm/engine
wasm-pack build --target web --out-dir ../pkg
cd ../..
pnpm --dir browser/frontend test:accessibility:rendered

The default output is ignored under browser/frontend/test-results/wbp-05a. Set WAVES_ACCESSIBILITY_OUTPUT_DIR to retain a named run; relative paths resolve from the repository root.

Manual-only Packaged macOS Smoke

Browser automation cannot verify how WKWebView announcements cross macOS NSAccessibility, how VoiceOver schedules repeated polite announcements, or how platform-drawn window/menu chrome affects focus presentation. Those checks remain manual and are not claimed by the Chromium evidence.

When packaged macOS application output is enabled, run this smoke with VoiceOver:

1. Launch the packaged Waves application at the default and minimum supported window sizes.
2. Set host zoom to 200 percent and traverse browser-owned actions with Tab and Shift+Tab; confirm the focused action remains visible and controls remain operable through vertical scrolling.
3. Start a network navigation that reaches loading and then a deterministic failure. Confirm VoiceOver announces the loading change once and the failure change once while the visible status and recovery toast remain available.
4. Repeat a successful navigation and a toast-only script/dialog event to confirm the unified live channel does not suppress later distinct messages.

The repository currently has packaging disabled in browser/src-tauri/tauri.conf.json, so no packaged-app/VoiceOver result is recorded for this slice. Native-control keyboard behavior remains covered by the existing browser story and Tauri tests.