assertion-error 2.0.1: AssertionResult

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 assertion-error.AssertionResult in pkg:npm/assertion-error@2.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/assertion-error@2.0.1
Demonstrate these symbols/APIs:
  - assertion-error.AssertionResult

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.

{"case":{"caseId":"case:sha256:b7e8bfdfc8a69ba45c8d8a1838a250c6baf3a7122f813b1574e984adff0f3aa4","contract":["AssertionResult instance has name 'AssertionResult' and ok true and does not inherit from Error","AssertionResult constructor copies custom properties from props object","AssertionResult constructor does not overwrite existing instance getters like name and ok","AssertionResult.prototype.toJSON serializes instance properties along with name and ok"],"goal":"verify assertion-error.AssertionResult in pkg:npm/assertion-error@2.0.1","kind":"HOW","packages":["pkg:npm/assertion-error@2.0.1"],"schemaVersion":1,"symbols":["assertion-error.AssertionResult"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/assertion-error@2.0.1"],"schemaVersion":1,"subject":"pkg:npm/assertion-error@2.0.1","symbols":["assertion-error.AssertionResult"],"verifierAdapter":"node-typescript@1"}

{
  "name": "assertion-result-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "assertion-result-sample",
      "version": "1.0.0",
      "dependencies": {
        "assertion-error": "2.0.1"
      }
    },
    "node_modules/assertion-error": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
      "integrity": "sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==",
      "license": "MIT",
      "engines": {
        "node": ">=12"
      }
    }
  }
}

{
  "name": "assertion-result-sample",
  "version": "1.0.0",
  "type": "module",
  "dependencies": {
    "assertion-error": "2.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify assertion-error.AssertionResult in pkg:npm/assertion-error@2.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/assertion-error@2.0.1"
  ],
  "symbols": [
    "assertion-error.AssertionResult"
  ]
}

import assert from 'node:assert';
import { AssertionResult } from 'assertion-error';

// 1. AssertionResult instance has name 'AssertionResult' and ok true and does not inherit from Error
const result = new AssertionResult();
assert.strictEqual(result.name, 'AssertionResult');
assert.strictEqual(result.ok, true);
assert.strictEqual(result instanceof Error, false);

// 2. AssertionResult constructor copies custom properties from props object
const customResult = new AssertionResult({
  message: 'check passed',
  details: { count: 5 },
  code: 0,
});
assert.strictEqual(customResult.message, 'check passed');
assert.deepStrictEqual(customResult.details, { count: 5 });
assert.strictEqual(customResult.code, 0);
assert.strictEqual(customResult.name, 'AssertionResult');
assert.strictEqual(customResult.ok, true);

// 3. AssertionResult constructor does not overwrite existing instance getters like name and ok
const protectedResult = new AssertionResult({
  name: 'OverriddenName',
  ok: false,
  extra: 'preserved',
});
assert.strictEqual(protectedResult.name, 'AssertionResult');
assert.strictEqual(protectedResult.ok, true);
assert.strictEqual(protectedResult.extra, 'preserved');

// 4. AssertionResult.prototype.toJSON serializes instance properties along with name and ok
const jsonResult = customResult.toJSON();
assert.strictEqual(jsonResult.name, 'AssertionResult');
assert.strictEqual(jsonResult.ok, true);
assert.strictEqual(jsonResult.message, 'check passed');
assert.deepStrictEqual(jsonResult.details, { count: 5 });
assert.strictEqual(jsonResult.code, 0);

console.log('Contract passed');