Persistence Validator (Future Test)

Purpose

This page will test cross-page data persistence using sessionStorage and the "Nuclear Persistence" cascade strategy. This ensures tracking data survives across navigations, redirects, and page reloads within a session.

What Will Be Tested

sessionStorage persistence across page navigations
Data recovery after redirects (302, meta refresh, JavaScript)
Multi-layer persistence cascade (sessionStorage → URL params → POST body)
Session ID continuity across the user journey
Data cleanup and expiration strategies

Nuclear Persistence Cascade

The "Nuclear Persistence" strategy uses multiple fallback layers to ensure data survives even in hostile browser environments:

Layer 1: sessionStorage (primary)

↓ If unavailable or cleared:

Layer 2: URL query parameters

↓ If stripped or lost:

Layer 3: Hidden form fields in POST

↓ If POST fails:

Layer 4: Cookie fallback (last resort)

Storage Mechanisms

sessionStorage (Primary)

Lifespan: Until browser tab closes
Capacity: ~5-10MB per origin
Scope: Same-origin only
Use case: Session ID, user journey data, form state

URL Parameters (Fallback Layer 2)

Lifespan: Duration of URL
Capacity: ~2KB practical limit
Scope: Visible in browser history
Use case: Session ID, source tracking

Future Implementation

When the ListenLayer tracking script is integrated, this page will include:

      // Future: Nuclear persistence write

      function persistData(key, value) {

        // Layer 1: sessionStorage

        try {

          sessionStorage.setItem(key, JSON.stringify(value));

        } catch (e) {

          console.warn('sessionStorage failed, using URL params');

        }

        // Layer 2: URL parameters (for critical data)

        const url = new URL(window.location);

        url.searchParams.set('_ll_' + key, value);

        history.replaceState({}, '', url);

      }

      // Future: Nuclear persistence read

      function readData(key) {

        // Try Layer 1: sessionStorage

        try {

          const stored = sessionStorage.getItem(key);

          if (stored) return JSON.parse(stored);

        } catch (e) {}

        // Fallback to Layer 2: URL parameters

        const params = new URLSearchParams(window.location.search);

        return params.get('_ll_' + key);

      }

Test Workflow (Phase 2)

The following test workflow will be implemented:

Page A: Write session data to sessionStorage
Navigate to Page B via redirect (data should persist)
Page B: Verify sessionStorage contains data from Page A
Clear sessionStorage (simulate hostile environment)
Navigate to Page C with URL params (Layer 2 fallback)
Page C: Verify data recovered from URL parameters
Submit form with hidden fields (Layer 3 fallback)
Verify data continuity across all 3 layers

Expected Behavior (Phase 2)

Session ID persists across all page navigations
User journey data is never lost (nuclear persistence)
Console logs show which persistence layer is active
Network tab shows tracking data in requests
Data is cleaned up when session expires