semver 7.8.5: reverse sort semantic versions with semver.rsort

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: reverse sort semantic versions with semver.rsort
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/semver@7.8.5
Demonstrate these symbols/APIs:
  - rsort
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@11.8.0
  - runtime: node@24.13.1

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:sha256:9c29e98eccb9d3647ad828afdf34fdb5bf8d1bff57de630aa8f7dba52ae77332","constraints":{"executionContext":"node"},"contract":["rsort orders versions in descending order by major minor and patch","rsort places release versions before their corresponding prerelease versions","rsort compares build metadata in descending order when versions are otherwise identical","rsort mutates the array in place and returns the same array reference","rsort supports loose mode for non-standard version strings"],"goal":"reverse sort semantic versions with semver.rsort","kind":"HOW","packages":["pkg:npm/semver@7.8.5"],"schemaVersion":1,"symbols":["rsort"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","ecosystem":"npm","executionContext":"node","language":"javascript","moduleSystem":"cjs","os":"windows","osVersionBucket":"11","packageManager":"npm","runtime":"node","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/semver@7.8.5"],"schemaVersion":1,"symbols":["rsort"],"verifierAdapter":"node-typescript@1"}

const semver = require('semver');

/**
 * Sort an array of semantic version strings in descending order.
 * @param {string[]} list
 * @param {boolean|object} [optionsOrLoose]
 * @returns {string[]}
 */
function reverseSortVersions(list, optionsOrLoose) {
  return semver.rsort(list, optionsOrLoose);
}

module.exports = {
  rsort: semver.rsort,
  reverseSortVersions
};

{
  "name": "sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample",
      "version": "1.0.0",
      "dependencies": {
        "semver": "7.8.5"
      }
    },
    "node_modules/semver": {
      "version": "7.8.5",
      "resolved": "https://registry.npmjs.org/semver/-/semver-7.8.5.tgz",
      "integrity": "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA==",
      "license": "ISC",
      "bin": {
        "semver": "bin/semver.js"
      },
      "engines": {
        "node": ">=10"
      }
    }
  }
}

{
  "name": "sample",
  "version": "1.0.0",
  "private": true,
  "main": "index.js",
  "dependencies": {
    "semver": "7.8.5"
  }
}

{
  "schemaVersion": 1,
  "goal": "reverse sort semantic versions with semver.rsort",
  "kind": "HOW",
  "packages": [
    "pkg:npm/semver@7.8.5"
  ],
  "symbols": [
    "rsort"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@11.8.0",
    "runtime": "node@24.13.1"
  }
}

const assert = require('assert');
const { rsort, reverseSortVersions } = require('../index.js');

// Assertion 1: rsort orders versions in descending order by major minor and patch
const versions = ['1.0.2', '1.10.0', '1.2.0', '1.0.10', '10.0.0', '2.0.0'];
const expectedNumeric = ['10.0.0', '2.0.0', '1.10.0', '1.2.0', '1.0.10', '1.0.2'];
assert.deepStrictEqual(rsort([...versions]), expectedNumeric);
assert.deepStrictEqual(reverseSortVersions([...versions]), expectedNumeric);

// Assertion 2: rsort places release versions before their corresponding prerelease versions
const prereleases = ['1.0.0-alpha', '1.0.0', '1.0.0-beta.2', '1.0.0-rc.1', '1.0.0-alpha.1', '1.0.0-beta'];
const expectedPrereleases = [
  '1.0.0',
  '1.0.0-rc.1',
  '1.0.0-beta.2',
  '1.0.0-beta',
  '1.0.0-alpha.1',
  '1.0.0-alpha'
];
assert.deepStrictEqual(rsort([...prereleases]), expectedPrereleases);
assert.deepStrictEqual(reverseSortVersions([...prereleases]), expectedPrereleases);

// Assertion 3: rsort compares build metadata in descending order when versions are otherwise identical
const builds = ['1.0.0+build.1', '1.0.0+build.10', '1.0.0+build.2'];
const expectedBuilds = ['1.0.0+build.10', '1.0.0+build.2', '1.0.0+build.1'];
assert.deepStrictEqual(rsort([...builds]), expectedBuilds);
assert.deepStrictEqual(reverseSortVersions([...builds]), expectedBuilds);

// Assertion 4: rsort mutates the array in place and returns the same array reference
const targetArray = ['1.0.0', '2.1.0'];
const returnedArray = rsort(targetArray);
assert.strictEqual(returnedArray, targetArray);
assert.deepStrictEqual(targetArray, ['2.1.0', '1.0.0']);

// Assertion 5: rsort supports loose mode for non-standard version strings
const looseVersions = ['=v2.0.0', 'v1.0.0', '  1.5.0  '];
const expectedLoose = ['=v2.0.0', '  1.5.0  ', 'v1.0.0'];
assert.deepStrictEqual(rsort([...looseVersions], { loose: true }), expectedLoose);
assert.deepStrictEqual(reverseSortVersions([...looseVersions], true), expectedLoose);

console.log('PASS: all contract assertions passed for semver.rsort');