UA Ledger · Playable Test Bench · draft for review
Teaching laboratory. Cases run in this page against the authored functions. This is not a device panel, network approval, analytics-delivery proof or campaign result. Inputs are synthetic.
A playable should not fail its whole startup because a non-essential preference cannot be saved. This fixture checks an explicit fallback for storage errors without claiming persistence succeeded.
Primary documentation: MDN: storage fallback (body read 2026-09-19).
| Case | Input | Expected | Fixed | Broken |
|---|
A pass shows that the application can continue with an honest non-persistent state. It does not prove privacy-mode behaviour, quota handling in every browser or survival across sessions. A fallback should preserve the current interaction while making no promise that the next launch will remember the preference.