The reviewer proved my behavioural claim false by running the stale-cache
mutant against the smoke: 11 vs 12 total calls — indistinguishable. Two real
defects hid behind that finding:
1. The cache keyed on _cfgEpoch, which ticks on every ACCEPTED PREVIEW —
the cache missed on every pointermove and the baseline was recomputed
~4 times per gesture (measured). The key is now the document identity
plus spacePhysicalGeometryFingerprint of its space: content, not a
counter. A preview overlay leaves the fingerprint alone; an in-place
structural commit changes it and honestly invalidates.
2. The smoke now counts BASELINE computations only (calls whose document is
_serverCfg) across two gestures with a commit in between, expecting
exactly 1 then exactly 2. A disabled cache lands near 20, an eternal
cache stays at 1 — every mutant class turns the smoke red, and the smoke
is now the mutant's guard alongside the source-contract unit.
Issue: #330
User-Visible: no
Codex
04bb54aef3