CodeSampleX

Sample

verify react.useMemo in pkg:npm/react@19.2.8

sha256:43f7228d74ce084ce9be60e73ec9bba58191797ea82530a96cf304a8f15703ac

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux 24 · ubuntu · glibc 2.39 x64 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…
2026-08-26

Case

HOW
Goal
verify react.useMemo in pkg:npm/react@19.2.8
Packages
Symbols
  • react.useMemo
Created
2026-08-26T08:11:36Z

Contract

  1. react exports useMemo as a function
  2. calling react.useMemo outside of an active component render cycle throws because the dispatcher is unassigned
  3. react.useMemo invokes factory function and caches the result on initial render
  4. react.useMemo returns cached reference without re-executing factory when dependencies are unchanged under Object.is equality
  5. react.useMemo recomputes value when dependencies change
  6. react.useMemo with empty dependency array maintains cached value across all re-renders
  7. react.useMemo with undefined dependencies re-executes factory on every render
  8. react.useMemo respects Object.is semantics distinguishing +0 and -0 while treating NaN as equal
  9. react.useMemo propagates factory exceptions synchronously without persisting a cached value

Files

  • NOTES.md
  • PROMPT.md
  • csx.json
  • package-lock.json
  • package.json
  • spec.json
  • src/index.mjs
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

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