Zero Patterns

Zero Query Patterns

Zero keeps cached data during re-sync (type === "unknown"). Never gate UI on "unknown" — it causes skeleton/content flash cycles.

• DO: Derive loading state from data emptiness + type: const isLoading = data.length === 0 && result.type !== "complete". This shows skeleton only on first load; once data is cached it persists through re-sync.
• DO: For singular queries (.byId): const isLoading = !item && result.type !== "complete".
• DO: Always compute derived data (stats, counts, filters) from the live query data — never gate computation on isLoading. This prevents values flashing to 0 during re-sync.
• DO NOT: Check result.type === "unknown" to show loading UI — Zero returns cached data during "unknown", so it's never truly empty after first load.
• DO NOT: Use per-query error hooks — connection errors are handled globally by ZeroConnectionMonitor in _app.tsx via useConnectionState().
• DO NOT: Pass unstable object references (e.g., session from ) as dependencies for ZeroProvider props — extract stable primitives (, ) instead. Unstable refs cause ZeroProvider to reinitialize and remount the entire app.