conformance — the KidLisp pixel oracle #

Renders the corpus (the top pieces by live hits, corpus.json) from a checkout and compares it against another, so a KidLisp change is judged by what it draws. This is the gate every agent PR runs; its sheets go in the PR body.

node kidlisp/conformance/oracle.mjs check                 # this checkout vs origin/main (~8 min, exit 1 = broke)
node kidlisp/conformance/oracle.mjs check --against HEAD  # vs your last commit
node kidlisp/conformance/oracle.mjs refresh --top 40      # re-pull the corpus from prod
node kidlisp/conformance/oracle.mjs render --out DIR [--repo PATH | --base URL] [--only bop,pie] [--at 1500,4000] [--video]
node kidlisp/conformance/oracle.mjs compare BEFORE AFTER --out DIR [--noise AGAIN]

check boots lith/server.mjs for both trees (no env or db needed; $code lookups are answered from prod by the oracle), renders the base twice and the change once, and writes before/, noise/, after/ and diff/ (with compare.md and a before/after sheet per flagged piece).

verdicts #

verdict	meaning	fails?
`same`	within the piece's own noise	no
`drift`	moved a little past its noise	no, sheet for the eye
`changed`	moved a lot; may be a chaotic piece being itself	no, sheet for the eye
`blank`	went flat and far from before	yes
`gone`	a steady piece became a different picture	yes
`error`	a console error the base didn't throw	yes

why it isn't pixel-exact (yet) #

KidLisp seeds ? from Date.now() and runs in a worker the harness can't clock, so the same code draws different frames run to run. The oracle judges by 64-bin colour histograms against each piece's measured self-noise. A deterministic mode (seeded ?, frame-stepped time, behind a URL flag) would make this exact, and is the first roadmap item it wants.

gotchas #

kidlisp.mjs is bundled into the disk worker. An edit renders nothing new until cd system && npm run build:disk-worker, and the bundle + manifest must be committed with it.
Clocks start at window.acBOOTED, not navigation: boot swings by seconds under load. Each piece gets its own browser context (shared service worker breaks parallel boots) and background throttling is off.
Local network noise (no db, no session server) is filtered out of errors.
Proven on 2026-09-23: identical trees pass (38 same, 2 chaotic flagged); a tree with wipe stubbed fails (4 blank, 1 gone).