punycode 2.3.1: convert punycode encoded domain names to unicode using punycode.toUnicode

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: convert punycode encoded domain names to unicode using punycode.toUnicode
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/punycode@2.3.1
Demonstrate these symbols/APIs:
  - punycode.toUnicode

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:ad90fa5f52e68ea88c52ba160dbe90e35f8eedd2cfd9bad5d13a870920128445","contract":["punycode.toUnicode converts Punycode ASCII domain names to Unicode characters","punycode.toUnicode leaves ASCII-only domain names unchanged"],"goal":"convert punycode encoded domain names to unicode using punycode.toUnicode","kind":"HOW","packages":["pkg:npm/punycode@2.3.1"],"schemaVersion":1,"symbols":["punycode.toUnicode"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/punycode@2.3.1"],"schemaVersion":1,"subject":"pkg:npm/punycode@2.3.1","symbols":["punycode.toUnicode"],"verifierAdapter":"node-typescript@1"}

const punycode = require('punycode/');

/**
 * Converts a Punycode ASCII domain name to its Unicode equivalent.
 * @param {string} domain - Domain name containing Punycode-encoded ASCII
 * @returns {string} Decoded Unicode domain name
 */
function convertDomainToUnicode(domain) {
  return punycode.toUnicode(domain);
}

module.exports = {
  convertDomainToUnicode
};

{
  "name": "punycode-tounicode-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "punycode-tounicode-sample",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "punycode": "2.3.1"
      }
    },
    "node_modules/punycode": {
      "version": "2.3.1",
      "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
      "integrity": "sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==",
      "license": "MIT",
      "engines": {
        "node": ">=6"
      }
    }
  }
}

{
  "name": "punycode-tounicode-sample",
  "version": "1.0.0",
  "description": "Convert punycode encoded domain names to unicode using punycode.toUnicode",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "punycode": "2.3.1"
  },
  "private": true,
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "convert punycode encoded domain names to unicode using punycode.toUnicode",
  "kind": "HOW",
  "packages": [
    "pkg:npm/punycode@2.3.1"
  ],
  "symbols": [
    "punycode.toUnicode"
  ]
}

const assert = require('assert');
const punycode = require('punycode/');
const { convertDomainToUnicode } = require('../index.js');

// 1. Direct symbol test: punycode.toUnicode converts Punycode ASCII domain names to Unicode characters
assert.strictEqual(
  punycode.toUnicode('xn--maana-pta.com'),
  'mañana.com',
  'punycode.toUnicode should decode Spanish domain xn--maana-pta.com to mañana.com'
);

assert.strictEqual(
  punycode.toUnicode('xn--bcher-kva.example.com'),
  'bücher.example.com',
  'punycode.toUnicode should decode German domain with umlaut'
);

// 2. Direct symbol test: punycode.toUnicode leaves ASCII-only domain names unchanged
assert.strictEqual(
  punycode.toUnicode('example.com'),
  'example.com',
  'punycode.toUnicode should leave ASCII domains unchanged'
);

// 3. Helper test
assert.strictEqual(
  convertDomainToUnicode('xn--maana-pta.com'),
  'mañana.com',
  'convertDomainToUnicode should return expected Unicode domain'
);

console.log('Contract assertions passed.');