iconv-lite 0.4.24: encodingExists

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 iconv-lite.encodingExists in pkg:npm/iconv-lite@0.4.24
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/iconv-lite@0.4.24
Demonstrate these symbols/APIs:
  - iconv-lite.encodingExists
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - runtime: node@22.23.2

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:a62ecd17e209f0335f4d1ea1975044d9cae8e1c0ae1f6bc65c3844cc71f1c816","constraints":{"executionContext":"node"},"contract":["assert iconv.encodingExists returns true for standard encodings including UTF-8, UTF-16, and ASCII","assert iconv.encodingExists returns true for case-insensitive and hyphenated alias names like utf-8, UTF8, and Utf-8","assert iconv.encodingExists returns true for legacy single-byte encodings including Windows-1252, Windows-1251, and ISO-8859-1","assert iconv.encodingExists returns true for CJK multibyte encodings including EUC-KR, Shift_JIS, and GBK","assert iconv.encodingExists returns false for unknown or invalid encoding names","assert iconv.encodingExists returns false for empty or non-string inputs"],"goal":"verify iconv-lite.encodingExists in pkg:npm/iconv-lite@0.4.24","kind":"HOW","packages":["pkg:npm/iconv-lite@0.4.24"],"schemaVersion":1,"symbols":["iconv-lite.encodingExists"]},"contractCommand":["node","test/contract.mjs"],"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/iconv-lite@0.4.24"],"schemaVersion":1,"subject":"pkg:npm/iconv-lite@0.4.24","symbols":["iconv-lite.encodingExists"],"verifierAdapter":"node-typescript@1"}

const iconv = require('iconv-lite');

/**
 * Checks whether the given character encoding is supported by iconv-lite.
 *
 * @param {string} encoding - The character encoding name or alias to test (e.g. 'utf-8', 'win1252', 'euc-kr').
 * @returns {boolean} True if the encoding is supported, false otherwise.
 */
function isEncodingSupported(encoding) {
  return iconv.encodingExists(encoding);
}

module.exports = {
  isEncodingSupported,
  iconv,
};

{
  "name": "sample-iconv-lite-encoding-exists",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-iconv-lite-encoding-exists",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "iconv-lite": "0.4.24"
      }
    },
    "node_modules/iconv-lite": {
      "version": "0.4.24",
      "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.24.tgz",
      "integrity": "sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==",
      "license": "MIT",
      "dependencies": {
        "safer-buffer": ">= 2.1.2 < 3"
      },
      "engines": {
        "node": ">=0.10.0"
      }
    },
    "node_modules/safer-buffer": {
      "version": "2.1.2",
      "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-iconv-lite-encoding-exists",
  "version": "1.0.0",
  "description": "Clean-room sample verifying iconv-lite.encodingExists functionality",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "iconv-lite": "0.4.24"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify iconv-lite.encodingExists in pkg:npm/iconv-lite@0.4.24",
  "kind": "HOW",
  "packages": [
    "pkg:npm/iconv-lite@0.4.24"
  ],
  "symbols": [
    "iconv-lite.encodingExists"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert';
import iconv from 'iconv-lite';
import { isEncodingSupported } from '../index.js';

// 1. Standard encodings
assert.strictEqual(isEncodingSupported('utf8'), true, 'iconv.encodingExists must return true for utf8');
assert.strictEqual(isEncodingSupported('utf-8'), true, 'iconv.encodingExists must return true for utf-8');
assert.strictEqual(isEncodingSupported('utf16le'), true, 'iconv.encodingExists must return true for utf16le');
assert.strictEqual(isEncodingSupported('ascii'), true, 'iconv.encodingExists must return true for ascii');

// 2. Case insensitivity and aliases
assert.strictEqual(isEncodingSupported('UTF-8'), true, 'iconv.encodingExists must be case-insensitive for UTF-8');
assert.strictEqual(isEncodingSupported('UTF8'), true, 'iconv.encodingExists must match alias UTF8');
assert.strictEqual(isEncodingSupported('Utf-8'), true, 'iconv.encodingExists must handle mixed-case Utf-8');

// 3. Legacy single-byte encodings
assert.strictEqual(isEncodingSupported('windows-1252'), true, 'iconv.encodingExists must return true for windows-1252');
assert.strictEqual(isEncodingSupported('win1251'), true, 'iconv.encodingExists must return true for win1251');
assert.strictEqual(isEncodingSupported('iso-8859-1'), true, 'iconv.encodingExists must return true for iso-8859-1');

// 4. Multibyte CJK encodings
assert.strictEqual(isEncodingSupported('euc-kr'), true, 'iconv.encodingExists must return true for euc-kr');
assert.strictEqual(isEncodingSupported('shift_jis'), true, 'iconv.encodingExists must return true for shift_jis');
assert.strictEqual(isEncodingSupported('gbk'), true, 'iconv.encodingExists must return true for gbk');

// 5. Unknown or invalid encoding names
assert.strictEqual(isEncodingSupported('unknown-encoding-xyz'), false, 'iconv.encodingExists must return false for unknown encodings');
assert.strictEqual(isEncodingSupported('not_a_real_charset'), false, 'iconv.encodingExists must return false for invalid encodings');

// 6. Empty or non-string inputs
assert.strictEqual(isEncodingSupported(''), false, 'iconv.encodingExists must return false for empty string');
assert.strictEqual(isEncodingSupported(null), false, 'iconv.encodingExists must return false for null');
assert.strictEqual(isEncodingSupported(undefined), false, 'iconv.encodingExists must return false for undefined');

console.log('All contract assertions passed.');