Previously, accessing a non-existent step via results.nonexistent would
throw an error. This fix makes both Deno Core and QuickJS return null
instead, enabling patterns like:
- results.nonexistent ?? 'default'
- results.nonexistent?.value ?? 'default'
The fix was applied to:
- js_eval.rs: handle_full_regex fast-path now uses .ok().flatten()
- js_eval_quickjs.rs: fallback path now uses .ok().unwrap_or(null)
Added flow engine test to verify the behavior.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>