CodeSampleX

Sample

check-error 2.1.3: compatibleConstructor

Verified sample for npm check-error 2.1.3: compatibleConstructor. The contract ran on node 22 · linux debian/x64 · docker and passed.

sha256:54c0f378a5be7b5da4b47b7e675478b518cc29a843629c9da23f887c6f22a45d

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 debian/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22@sha256:8a34c4ab3ea2…
2026-09-06

Case

HOW
Goal
verify check-error.compatibleConstructor in pkg:npm/check-error@2.1.3
Packages
Symbols
  • check-error.compatibleConstructor
Environment
node 22.23.2
Created
2026-09-06T17:53:48Z

Contract

  1. compatibleConstructor matches error instances against matching constructor functions
  2. compatibleConstructor matches error instances against inherited superclass constructor functions
  3. compatibleConstructor matches error instances against another error instance with compatible constructors
  4. compatibleConstructor returns false when constructors do not match or inherit
  5. compatibleConstructor returns false for non-constructor values and throws TypeError for null target

Files

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

Download the source artifact (tar.gz)

Source

PROMPT.md
Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify check-error.compatibleConstructor in pkg:npm/check-error@2.1.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/check-error@2.1.3
Demonstrate these symbols/APIs:
  - check-error.compatibleConstructor

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.
csx.json
{"case":{"caseId":"case:sha256:3d57342d5d14eb292985354e06efb333f7f611ac72aeedaaae265ec5b2838ebe","contract":["compatibleConstructor matches error instances against matching constructor functions","compatibleConstructor matches error instances against inherited superclass constructor functions","compatibleConstructor matches error instances against another error instance with compatible constructors","compatibleConstructor returns false when constructors do not match or inherit","compatibleConstructor returns false for non-constructor values and throws TypeError for null target"],"goal":"verify check-error.compatibleConstructor in pkg:npm/check-error@2.1.3","kind":"HOW","packages":["pkg:npm/check-error@2.1.3"],"schemaVersion":1,"symbols":["check-error.compatibleConstructor"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/check-error@2.1.3"],"schemaVersion":1,"subject":"pkg:npm/check-error@2.1.3","symbols":["check-error.compatibleConstructor"],"verifierAdapter":"node-typescript@1"}
package-lock.json
{
  "name": "sample-check-error",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-check-error",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "check-error": "2.1.3"
      }
    },
    "node_modules/check-error": {
      "version": "2.1.3",
      "resolved": "https://registry.npmjs.org/check-error/-/check-error-2.1.3.tgz",
      "integrity": "sha512-PAJdDJusoxnwm1VwW07VWwUN1sl7smmC3OKggvndJFadxxDRyFJBX/ggnu/KE4kQAB7a3Dp8f/YXC1FlUprWmA==",
      "license": "MIT",
      "engines": {
        "node": ">= 16"
      }
    }
  }
}
package.json
{
  "name": "sample-check-error",
  "version": "1.0.0",
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "check-error": "2.1.3"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify check-error.compatibleConstructor in pkg:npm/check-error@2.1.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/check-error@2.1.3"
  ],
  "symbols": [
    "check-error.compatibleConstructor"
  ]
}
test/contract.mjs
import assert from 'node:assert/strict';
import { compatibleConstructor } from 'check-error';

// 1. compatibleConstructor matches error instances against matching constructor functions
const standardErr = new Error('standard error');
const typeErr = new TypeError('type error');
const rangeErr = new RangeError('range error');

assert.equal(compatibleConstructor(standardErr, Error), true);
assert.equal(compatibleConstructor(typeErr, TypeError), true);
assert.equal(compatibleConstructor(rangeErr, RangeError), true);

// 2. compatibleConstructor matches error instances against inherited superclass constructor functions
class CustomAppError extends Error {}
class SpecificServiceError extends CustomAppError {}

const customErr = new CustomAppError('custom error');
const specificErr = new SpecificServiceError('specific error');

assert.equal(compatibleConstructor(typeErr, Error), true);
assert.equal(compatibleConstructor(rangeErr, Error), true);
assert.equal(compatibleConstructor(customErr, Error), true);
assert.equal(compatibleConstructor(customErr, CustomAppError), true);
assert.equal(compatibleConstructor(specificErr, CustomAppError), true);
assert.equal(compatibleConstructor(specificErr, Error), true);

// 3. compatibleConstructor matches error instances against another error instance with compatible constructors
const anotherStandardErr = new Error('another standard error');
const anotherTypeErr = new TypeError('another type error');

assert.equal(compatibleConstructor(standardErr, anotherStandardErr), true);
assert.equal(compatibleConstructor(typeErr, anotherTypeErr), true);
assert.equal(compatibleConstructor(customErr, standardErr), true);
assert.equal(compatibleConstructor(specificErr, customErr), true);

// 4. compatibleConstructor returns false when constructors do not match or inherit
assert.equal(compatibleConstructor(standardErr, TypeError), false);
assert.equal(compatibleConstructor(standardErr, RangeError), false);
assert.equal(compatibleConstructor(standardErr, CustomAppError), false);
assert.equal(compatibleConstructor(standardErr, typeErr), false);
assert.equal(compatibleConstructor(standardErr, customErr), false);
assert.equal(compatibleConstructor(typeErr, RangeError), false);
assert.equal(compatibleConstructor(customErr, SpecificServiceError), false);
assert.equal(compatibleConstructor(customErr, specificErr), false);

// 5. compatibleConstructor returns false for non-constructor values and throws TypeError for null target
assert.equal(compatibleConstructor(standardErr, undefined), false);
assert.equal(compatibleConstructor(standardErr, {}), false);
assert.equal(compatibleConstructor(standardErr, 'Error'), false);
assert.equal(compatibleConstructor(standardErr, 123), false);
assert.equal(compatibleConstructor(standardErr, () => {}), false);
assert.throws(() => compatibleConstructor(standardErr, null), TypeError);

console.log('All check-error.compatibleConstructor contract assertions passed.');

Origin Seeder

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