node-releases 2.0.56: slice

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 node-releases.slice in pkg:npm/node-releases@2.0.56
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/node-releases@2.0.56
Demonstrate these symbols/APIs:
  - node-releases.slice

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:sha256:32cf9a9b67a9dc2626653f7cb4a3a0d5b41ab301098920d4c74a4024256a27c9","contract":["slice(start, end) returns a contiguous sub-range of release entries without mutating envs","slice(-n) extracts the latest n release entries from the tail of the dataset","slice(start, -endOffset) combines positive start and negative end index","slice() with no arguments returns a distinct shallow copy of all release entries","slice with start \u003e= length or start \u003e= end returns an empty array","CommonJS require of envs.json supports identical slice semantics"],"goal":"verify node-releases.slice in pkg:npm/node-releases@2.0.56","kind":"HOW","packages":["pkg:npm/node-releases@2.0.56"],"schemaVersion":1,"symbols":["node-releases.slice"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","runtime":"node","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/node-releases@2.0.56"],"schemaVersion":1,"subject":"pkg:npm/node-releases@2.0.56","symbols":["node-releases.slice"],"verifierAdapter":"node-typescript@1"}

{
  "name": "verify-node-releases-slice",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "verify-node-releases-slice",
      "version": "1.0.0",
      "dependencies": {
        "node-releases": "2.0.56"
      }
    },
    "node_modules/node-releases": {
      "version": "2.0.56",
      "resolved": "https://registry.npmjs.org/node-releases/-/node-releases-2.0.56.tgz",
      "integrity": "sha512-x0InOIyzgdk+eyaWaRJFH5snEtiImgBgblZ2CyPrLmqqcuMQkEvcDPHbzqbD8eDsSeJbVOjn+crzyzHaM4D+/A==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      }
    }
  }
}

{
  "name": "verify-node-releases-slice",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "node-releases": "2.0.56"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify node-releases.slice in pkg:npm/node-releases@2.0.56",
  "kind": "HOW",
  "packages": [
    "pkg:npm/node-releases@2.0.56"
  ],
  "symbols": [
    "node-releases.slice"
  ]
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import envs from 'node-releases/data/processed/envs.json' with { type: 'json' };

const require = createRequire(import.meta.url);
const cjsEnvs = require('node-releases/data/processed/envs.json');

// Verify baseline envs dataset
assert.ok(Array.isArray(envs), 'processed envs.json must export an array');
const totalCount = envs.length;
assert.ok(totalCount > 10, 'envs dataset must contain multiple release entries');

// 1. slice(start, end) returns a contiguous sub-range of release entries without mutating envs
const subRange = envs.slice(2, 7);
assert.equal(subRange.length, 5);
assert.equal(envs.length, totalCount);
for (let i = 0; i < 5; i++) {
  assert.deepEqual(subRange[i], envs[2 + i]);
  assert.equal(typeof subRange[i].version, 'string');
  assert.equal(typeof subRange[i].date, 'string');
}

// 2. slice(-n) extracts the latest n release entries from the tail of the dataset
const latestThree = envs.slice(-3);
assert.equal(latestThree.length, 3);
assert.deepEqual(latestThree[0], envs[totalCount - 3]);
assert.deepEqual(latestThree[2], envs[totalCount - 1]);

// 3. slice(start, -endOffset) combines positive start and negative end index
const trimmed = envs.slice(1, -1);
assert.equal(trimmed.length, totalCount - 2);
assert.deepEqual(trimmed[0], envs[1]);
assert.deepEqual(trimmed[trimmed.length - 1], envs[totalCount - 2]);

// 4. slice() with no arguments returns a distinct shallow copy of all release entries
const cloned = envs.slice();
assert.notEqual(cloned, envs);
assert.equal(cloned.length, totalCount);
assert.deepEqual(cloned[0], envs[0]);
assert.deepEqual(cloned[totalCount - 1], envs[totalCount - 1]);

// 5. slice with start >= length or start >= end returns an empty array
assert.deepEqual(envs.slice(totalCount), []);
assert.deepEqual(envs.slice(5, 2), []);

// 6. CommonJS require of envs.json supports identical slice semantics
const cjsHead = cjsEnvs.slice(0, 4);
assert.equal(cjsHead.length, 4);
assert.deepEqual(cjsHead, envs.slice(0, 4));