test: regression coverage for favicon mask-icon and error handler fallbacks

[cursor]

Asana Task/Github Issue: Test coverage automation (cron)

Description

Adds missing regression tests for two recently merged production changes:

1. Favicon mask-icon exclusion (Exclude Safari mask-icon links from favicon collection #2772) — The dedicated unit test was removed during review with the assumption integration tests already covered getFaviconList, but no test asserted Safari rel="mask-icon" links are excluded. This PR adds unit tests (jsdom) and an integration test with mask-icon fixtures.

2. Special-pages error handler fallbacks (Fall back to ErrorEvent.message in special-pages error handlers #2714) — Production handlers in history and new-tab were updated alongside onboarding, but only onboarding received integration coverage for cross-origin ErrorEvent.message fallback, unknown-error fallback, non-Error throws, and primitive rejection reasons. This PR brings history and new-tab to parity.

Risky behavior now covered

• Safari mask-icon / MASK-ICON links are excluded from favicon collection while real SVG favicons remain
• Cross-origin script errors report event.message instead of [uncaught] unknown error
• Falsy rejection reasons (undefined, null, 0) report distinct messages instead of bucketing to a generic unknown

Test files added/updated

• injected/unit-test/favicon.spec.js (new)
• injected/integration-test/favicon.spec.js
• injected/integration-test/test-pages/favicon/svg-test.html + mask-icon SVG fixtures
• special-pages/pages/history/integration-tests/history.spec.js
• special-pages/pages/new-tab/integration-tests/new-tab.spec.js

Why these tests materially reduce regression risk

• Mask-icon mis-collection caused solid black squares in production favicon UI; selector regressions would reintroduce that
• Error-handler fallbacks fixed a production telemetry spike (m_mac_onboarding_exception-reported); history/new-tab share identical handler logic and would silently regress without page-specific tests

Testing Steps

• cd injected && npx jasmine unit-test/favicon.spec.js
• cd injected && npm run test-int -- favicon.spec.js --grep "mask-icon" --reporter list
• cd special-pages && npm run test-int -- pages/history/integration-tests/history.spec.js --grep "global error listeners" --reporter list
• cd special-pages && npm run test-int -- pages/new-tab/integration-tests/new-tab.spec.js --grep "global error listeners" --reporter list

Checklist

• I have tested this change locally
• I have tested this change locally in all supported browsers
• This change will be visible to users
• I have added automated tests that cover this change
• I have ensured the change is gated by config
• This change was covered by a ship review
• This change was covered by a tech design
• Any dependent config has been merged

  

[github-actions]

Build Branch

Branch	pr-releases/cursor/test-coverage-automation-b7a5
Commit	c5880b591f
Updated	June 29, 2026 at 8:07:28 AM UTC

Static preview entry points

• Docs: docs/index.html
• Static pages: build/integration/pages/index.html
• Integration pages: injected/integration-test/test-pages/index.html

QR codes (mobile preview)

Entry point	QR code
Docs
Static pages
Integration pages

Integration commands

npm (Android / Extension):

npm i github:duckduckgo/content-scope-scripts#pr-releases/cursor/test-coverage-automation-b7a5

Swift Package Manager (Apple):

.package(url: "https://github.com/duckduckgo/content-scope-scripts.git", branch: "pr-releases/cursor/test-coverage-automation-b7a5")

git submodule (Windows):

git -C submodules/content-scope-scripts fetch origin pr-releases/cursor/test-coverage-automation-b7a5
git -C submodules/content-scope-scripts checkout origin/pr-releases/cursor/test-coverage-automation-b7a5

Pin to exact commit

npm (Android / Extension):

npm i github:duckduckgo/content-scope-scripts#c5880b591ff25ce22220ada257a11071bbaa12c2

Swift Package Manager (Apple):

.package(url: "https://github.com/duckduckgo/content-scope-scripts.git", revision: "c5880b591ff25ce22220ada257a11071bbaa12c2")

git submodule (Windows):

git -C submodules/content-scope-scripts fetch origin pr-releases/cursor/test-coverage-automation-b7a5
git -C submodules/content-scope-scripts checkout c5880b591ff25ce22220ada257a11071bbaa12c2

[github-actions]

[Beta] Generated file diff

Time updated: Mon, 29 Jun 2026 08:08:17 GMT