@babel/helper-validator-identifier 8.0.4: isStrictReservedWord

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 @babel/helper-validator-identifier.isStrictReservedWord in pkg:npm/%40babel/helper-validator-identifier@8.0.4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40babel/helper-validator-identifier@8.0.4
Demonstrate these symbols/APIs:
  - @babel/helper-validator-identifier.isStrictReservedWord
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:sha256:87b75ddc8f732b3795c462064658775932c012a5e55de70320f4d2f3f97ca028","constraints":{"executionContext":"node"},"contract":["isStrictReservedWord returns true for strict mode reserved words (implements, interface, let, package, private, protected, public, static, yield)","isStrictReservedWord returns true for enum in both module and script contexts","isStrictReservedWord returns true for await when inModule is true","isStrictReservedWord returns false for await when inModule is false or omitted","isStrictReservedWord returns false for standard keywords, regular identifiers, and casing variations"],"goal":"verify @babel/helper-validator-identifier.isStrictReservedWord in pkg:npm/%40babel/helper-validator-identifier@8.0.4","kind":"HOW","packages":["pkg:npm/%40babel/helper-validator-identifier@8.0.4"],"schemaVersion":1,"symbols":["@babel/helper-validator-identifier.isStrictReservedWord"]},"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","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40babel/helper-validator-identifier@8.0.4"],"schemaVersion":1,"subject":"pkg:npm/%40babel/helper-validator-identifier@8.0.4","symbols":["@babel/helper-validator-identifier.isStrictReservedWord"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-babel-helper-validator-identifier",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-babel-helper-validator-identifier",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@babel/helper-validator-identifier": "8.0.4"
      }
    },
    "node_modules/@babel/helper-validator-identifier": {
      "version": "8.0.4",
      "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-8.0.4.tgz",
      "integrity": "sha512-4wFaiLd0bVo4cIoTXI3zKI038NIWE/cr3jvBjejOVYVxV/m8Ltav1USiGzG1fmS5J2RhgEOgXNNK46cRPnRsrg==",
      "license": "MIT",
      "engines": {
        "node": "^22.18.0 || >=24.11.0"
      }
    }
  }
}

{
  "name": "sample-babel-helper-validator-identifier",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of @babel/helper-validator-identifier.isStrictReservedWord",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "@babel/helper-validator-identifier": "8.0.4"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @babel/helper-validator-identifier.isStrictReservedWord in pkg:npm/%40babel/helper-validator-identifier@8.0.4",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40babel/helper-validator-identifier@8.0.4"
  ],
  "symbols": [
    "@babel/helper-validator-identifier.isStrictReservedWord"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "runtime": "node@22.23.2"
  }
}

const { isStrictReservedWord } = require('@babel/helper-validator-identifier');

/**
 * Checks whether a given word is a strict reserved word in the specified module context.
 * @param {string} word - The identifier string to check.
 * @param {boolean} [inModule=false] - Whether the context is inside an ES module.
 * @returns {boolean} True if the word is a strict reserved word.
 */
function checkIsStrictReservedWord(word, inModule = false) {
  return isStrictReservedWord(word, inModule);
}

/**
 * Filters a list of words and returns only those that are strict reserved words.
 * @param {string[]} words - Array of words to check.
 * @param {boolean} [inModule=false] - Whether the context is inside an ES module.
 * @returns {string[]} Array containing only strict reserved words.
 */
function filterStrictReservedWords(words, inModule = false) {
  if (!Array.isArray(words)) {
    return [];
  }
  return words.filter((word) => typeof word === 'string' && isStrictReservedWord(word, inModule));
}

module.exports = {
  checkIsStrictReservedWord,
  filterStrictReservedWords,
};

import assert from 'node:assert';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const { checkIsStrictReservedWord, filterStrictReservedWords } = require('../src/index.js');
const { isStrictReservedWord } = require('@babel/helper-validator-identifier');

async function runContract() {
  // 1. isStrictReservedWord returns true for strict mode reserved words (implements, interface, let, package, private, protected, public, static, yield)
  const strictReservedWords = [
    'implements',
    'interface',
    'let',
    'package',
    'private',
    'protected',
    'public',
    'static',
    'yield',
  ];

  for (const word of strictReservedWords) {
    assert.strictEqual(isStrictReservedWord(word, true), true, `expected isStrictReservedWord("${word}", true) to be true`);
    assert.strictEqual(isStrictReservedWord(word, false), true, `expected isStrictReservedWord("${word}", false) to be true`);
    assert.strictEqual(isStrictReservedWord(word), true, `expected isStrictReservedWord("${word}") to be true`);
    assert.strictEqual(checkIsStrictReservedWord(word, true), true, `expected checkIsStrictReservedWord("${word}", true) to be true`);
    assert.strictEqual(checkIsStrictReservedWord(word, false), true, `expected checkIsStrictReservedWord("${word}", false) to be true`);
    assert.strictEqual(checkIsStrictReservedWord(word), true, `expected checkIsStrictReservedWord("${word}") to be true`);
  }

  // 2. isStrictReservedWord returns true for enum in both module and script contexts
  assert.strictEqual(isStrictReservedWord('enum', true), true, 'expected isStrictReservedWord("enum", true) to be true');
  assert.strictEqual(isStrictReservedWord('enum', false), true, 'expected isStrictReservedWord("enum", false) to be true');
  assert.strictEqual(isStrictReservedWord('enum'), true, 'expected isStrictReservedWord("enum") to be true');
  assert.strictEqual(checkIsStrictReservedWord('enum', true), true, 'expected checkIsStrictReservedWord("enum", true) to be true');
  assert.strictEqual(checkIsStrictReservedWord('enum', false), true, 'expected checkIsStrictReservedWord("enum", false) to be true');
  assert.strictEqual(checkIsStrictReservedWord('enum'), true, 'expected checkIsStrictReservedWord("enum") to be true');

  // 3. isStrictReservedWord returns true for await when inModule is true
  assert.strictEqual(isStrictReservedWord('await', true), true, 'expected isStrictReservedWord("await", true) to be true');
  assert.strictEqual(checkIsStrictReservedWord('await', true), true, 'expected checkIsStrictReservedWord("await", true) to be true');

  // 4. isStrictReservedWord returns false for await when inModule is false or omitted
  assert.strictEqual(Boolean(isStrictReservedWord('await', false)), false, 'expected isStrictReservedWord("await", false) to be false');
  assert.strictEqual(Boolean(isStrictReservedWord('await')), false, 'expected isStrictReservedWord("await") to be false');
  assert.strictEqual(Boolean(checkIsStrictReservedWord('await', false)), false, 'expected checkIsStrictReservedWord("await", false) to be false');
  assert.strictEqual(Boolean(checkIsStrictReservedWord('await')), false, 'expected checkIsStrictReservedWord("await") to be false');

  // 5. isStrictReservedWord returns false for standard keywords, regular identifiers, and casing variations
  const nonStrictReservedWords = [
    'if',
    'else',
    'for',
    'while',
    'function',
    'return',
    'var',
    'const',
    'class',
    'import',
    'export',
    'foo',
    'bar',
    'myIdentifier',
    'LET',
    'Let',
    'IMPLEMENTS',
    'Implements',
    'ENUM',
    'Enum',
    'AWAIT',
    'Await',
  ];

  for (const word of nonStrictReservedWords) {
    assert.strictEqual(Boolean(isStrictReservedWord(word, true)), false, `expected isStrictReservedWord("${word}", true) to be false`);
    assert.strictEqual(Boolean(isStrictReservedWord(word, false)), false, `expected isStrictReservedWord("${word}", false) to be false`);
    assert.strictEqual(Boolean(checkIsStrictReservedWord(word, true)), false, `expected checkIsStrictReservedWord("${word}", true) to be false`);
    assert.strictEqual(Boolean(checkIsStrictReservedWord(word, false)), false, `expected checkIsStrictReservedWord("${word}", false) to be false`);
  }

  // Helper validation: filterStrictReservedWords
  const testList = ['foo', 'let', 'bar', 'await', 'implements', 'if', 'enum', 'static'];
  const filteredModule = filterStrictReservedWords(testList, true);
  assert.deepStrictEqual(filteredModule, ['let', 'await', 'implements', 'enum', 'static']);

  const filteredScript = filterStrictReservedWords(testList, false);
  assert.deepStrictEqual(filteredScript, ['let', 'implements', 'enum', 'static']);

  assert.deepStrictEqual(filterStrictReservedWords([]), []);
  assert.deepStrictEqual(filterStrictReservedWords(null), []);

  console.log('Contract tests passed successfully.');
}

runContract().catch((err) => {
  console.error('Contract test failed:', err);
  process.exit(1);
});