CodeSampleX

Sample

verify es-toolkit.isError in pkg:npm/es-toolkit@1.50.0

sha256:ad70b3e6a6df5f63bb07512422ad186c31aae9b1413b6d97ac9b2f5ddb8c3e8d

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 node 22.23 linux 24 · ubuntu · glibc 2.39 x64 node 22.23 javascript npm 10

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…
2026-08-27

Case

HOW
Goal
verify es-toolkit.isError in pkg:npm/es-toolkit@1.50.0
Packages
Symbols
  • es-toolkit.isError
Environment
node 22.23.2
Created
2026-08-27T23:56:00Z

Contract

  1. isError is exported from es-toolkit root and es-toolkit/predicate subpath as the identical function
  2. isError returns true for standard Error instances including TypeError and RangeError
  3. isError returns true for custom error classes extending Error
  4. isError returns false for non-error values including strings, numbers, booleans, and null or undefined
  5. isError returns false for plain objects with error-like properties

Files

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

Download the source artifact (tar.gz)

Origin Seeder

anonymous