punycode 2.3.1: decode

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 punycode.decode in pkg:npm/punycode@2.3.1
Kind: HOW

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

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:sha256:9792940e595fcf7d2174de2dc0773ccce82b03d19cbcafacf9efe9037281cbdc","contract":["punycode.decode converts Punycode encoded ASCII strings containing non-basic code points to Unicode strings","punycode.decode decodes basic ASCII strings with trailing hyphen delimiter","punycode.decode throws RangeError on invalid input"],"goal":"verify punycode.decode in pkg:npm/punycode@2.3.1","kind":"HOW","packages":["pkg:npm/punycode@2.3.1"],"schemaVersion":1,"symbols":["punycode.decode"]},"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.decode"],"verifierAdapter":"node-typescript@1"}

const punycode = require('punycode/');

/**
 * Decodes a Punycode string of ASCII symbols to a string of Unicode symbols.
 *
 * @param {string} input - The Punycode string to decode.
 * @returns {string} The decoded Unicode string.
 */
function decode(input) {
  return punycode.decode(input);
}

module.exports = {
  decode,
  punycode
};

{
  "name": "punycode-decode-verification",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "punycode-decode-verification",
      "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-decode-verification",
  "version": "1.0.0",
  "description": "verify punycode.decode in pkg:npm/punycode@2.3.1",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "punycode": "2.3.1"
  },
  "private": true,
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify punycode.decode in pkg:npm/punycode@2.3.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/punycode@2.3.1"
  ],
  "symbols": [
    "punycode.decode"
  ]
}

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

// 1. Verify punycode.decode converts Punycode encoded ASCII string to Unicode string
assert.strictEqual(
  punycode.decode('maana-pta'),
  'mañana',
  'punycode.decode should decode Spanish word with basic prefix'
);

assert.strictEqual(
  punycode.decode('bcher-kva'),
  'bücher',
  'punycode.decode should decode German umlaut word'
);

assert.strictEqual(
  punycode.decode('--dqo34k'),
  '☃-⌘',
  'punycode.decode should decode Unicode symbols with hyphen'
);

assert.strictEqual(
  punycode.decode('wgv71a119e'),
  '日本語',
  'punycode.decode should decode pure non-basic characters'
);

assert.strictEqual(
  decode('maana-pta'),
  'mañana',
  'exported decode function should decode Punycode string'
);

// 2. Verify punycode.decode handles basic ASCII strings with trailing hyphen delimiter
assert.strictEqual(
  punycode.decode('example-'),
  'example',
  'punycode.decode should decode basic ASCII string with trailing delimiter'
);

assert.strictEqual(
  decode('hello world-'),
  'hello world',
  'exported decode function should decode basic string with trailing delimiter'
);

// 3. Verify punycode.decode throws RangeError on invalid input
assert.throws(
  () => {
    punycode.decode('-dqo34k');
  },
  {
    name: 'RangeError'
  },
  'punycode.decode should throw RangeError for malformed punycode input'
);

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