PWA Phase 3: Add test cleanup for analytics singleton to prevent memory leaks

[kevalyq]

🧹 Test Infrastructure Issue

File: src/lib/analytics.test.ts
Severity: LOW
Origin: Copilot review comment in PR #100

Problem

The OfflineAnalytics singleton is created at module load time and persists across all test runs:

// In analytics.ts
let analyticsInstance: OfflineAnalytics | null = null;
try {
  analyticsInstance = new OfflineAnalytics();  // ← Created once at module load
} catch (error) {
  console.error("Failed to initialize analytics singleton:", error);
}

Issue: The singleton:

• Registers global event listeners (window.addEventListener('online', ...))
• Starts periodic sync interval (setInterval)
• Persists across test runs with active listeners/intervals
• Can cause test interference and memory leaks

Expected Behavior

Either:

1. Tests should clean up the singleton after each test, OR
2. Document that singleton persistence is intentional for production

Proposed Solution

Option A: Add cleanup in tests (Recommended)

// In analytics.test.ts
afterEach(() => {
  vi.restoreAllMocks();
  // Clean up singleton to prevent memory leaks and test interference
  if (analytics && typeof analytics.destroy === "function") {
    analytics.destroy();
  }
});

Option B: Document intentional behavior

If singleton persistence is intentional for production (event listeners should live for entire app lifetime), add comment:

// NOTE: Singleton persists across tests by design
// Event listeners remain active for app lifetime in production
// Test isolation is not affected as long as vi.clearAllMocks() is used

Context

• Related to PR feat: Implement PWA Phase 3 features (Push Notifications, Share Target API, Offline Analytics) #100 (PWA Phase 3 implementation)
• Copilot comment: "Potential memory leak: analytics singleton never cleaned up between tests"
• Not causing test failures currently, but good practice to address

Acceptance Criteria

• Choose Option A (cleanup) or Option B (document)
• If Option A: Add afterEach cleanup hook
• If Option A: Verify all tests still pass after cleanup
• If Option B: Add explanatory comment in both analytics.ts and analytics.test.ts
• Consider refactoring to factory pattern if cleanup becomes complex

[github-actions]

✅ This issue has been added to the SecPal Feature Roadmap with status: 💡 Ideas

New idea - needs discussion and evaluation

Status Flow:
💡 Ideas → 💬 Discussion → 📥 Backlog → 📋 Planned → 🚧 In Progress → 👀 In Review → ✅ Done

Note: Ideas that won't be implemented should be moved to 🚫 Won't Do with a reason.