[Maxwell-tom]

Overview

This PR adds direct test coverage for frontend/public/sw.js, the service worker that handles push events and notification clicks. Previously, notification tests mocked the subscribe/unsubscribe helpers and never executed the worker script, so regressions in push payload parsing, waitUntil lifetimes, window reuse, or openWindow behavior could go undetected. The new harness runs the actual script and asserts on those paths.

Related Issue

Changes

🧪 Service Worker Test Harness

• [ADD] frontend/src/__tests__/service-worker.test.ts

  • Loads and executes public/sw.js inside a worker-like harness.
  • Push handling: valid JSON payload, malformed JSON / plain text payload, and missing push payload.
  • Notification click handling: with an existing window (close/navigate behavior) and with no open window (openWindow behavior), including event.waitUntil lifetime assertions.

• [MODIFY] frontend/public/sw.js

  • Adjustments needed so the script can be evaluated under the harness and the tested branches are reachable.

• [MODIFY] frontend/src/__tests__/notifications.test.tsx

  • Updated to account for the real service-worker behavior exercised by the new tests.

• [MODIFY] frontend/src/__tests__/setup.ts

  • Shared test setup for the worker globals (self, clients, registration) used by the harness.

Verification Results

npm test -- src/__tests__/service-worker.test.ts

Acceptance Criteria	Status
Execute the actual service-worker script in a worker harness; test valid JSON, malformed JSON/text, and missing push payloads	✅ Covered in service-worker.test.ts
Test notification clicks with an existing window and with no window, asserting close/navigation/openWindow and event.waitUntil	✅ Covered in service-worker.test.ts

Closes #1712