@babel/types 7.29.8: identifier

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/types.identifier in pkg:npm/%40babel/types@7.29.8
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40babel/types@7.29.8
Demonstrate these symbols/APIs:
  - @babel/types.identifier

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:sha256:1302532634dad1cda52b695f6158a64b38a50d2eec560e4c4b881893c925272f","contract":["types.identifier creates an Identifier AST node with the specified name string and type 'Identifier'","types.isIdentifier returns true for Identifier nodes with optional name matching and false for non-Identifier nodes","types.assertIdentifier succeeds for valid Identifier nodes and throws an Error for non-Identifier nodes","types.isValidIdentifier correctly validates JavaScript identifier names","Identifier nodes created with types.identifier integrate into larger AST constructs like VariableDeclarator and MemberExpression","types.cloneNode produces an independent equivalent copy of an Identifier node"],"goal":"verify @babel/types.identifier in pkg:npm/%40babel/types@7.29.8","kind":"HOW","packages":["pkg:npm/%40babel/types@7.29.8"],"schemaVersion":1,"symbols":["@babel/types.identifier"]},"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/types@7.29.8"],"schemaVersion":1,"subject":"pkg:npm/%40babel/types@7.29.8","symbols":["@babel/types.identifier"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-babel-types-identifier",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-babel-types-identifier",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@babel/types": "7.29.8"
      }
    },
    "node_modules/@babel/helper-string-parser": {
      "version": "7.29.7",
      "resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.29.7.tgz",
      "integrity": "sha512-Pb5ijPrZ89GDH8223L4UP8i6QApWxs04RbPQJTeWDV0/keR2E36MeKnyr6LYmUUvqRRI+Iv87SuF1W6ErINzYw==",
      "license": "MIT",
      "engines": {
        "node": ">=6.9.0"
      }
    },
    "node_modules/@babel/helper-validator-identifier": {
      "version": "7.29.7",
      "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.29.7.tgz",
      "integrity": "sha512-qehxGkRj55h/ff8EMaJ+cYhyaKlHIxqYDn682wQD7RNp9UujOQsHog2uS0r2vzr4pW+sXf90NeeayjcNaX3fFg==",
      "license": "MIT",
      "engines": {
        "node": ">=6.9.0"
      }
    },
    "node_modules/@babel/types": {
      "version": "7.29.8",
      "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.29.8.tgz",
      "integrity": "sha512-Vj1jF3cPfxg7OAfoI7QnVKLoILlm2JF9pnVHrX8qx7AHMiYWT+NDAA7jChlNgRS4WTLc/fD1lXLmPixluj+3Gg==",
      "license": "MIT",
      "dependencies": {
        "@babel/helper-string-parser": "^7.29.7",
        "@babel/helper-validator-identifier": "^7.29.7"
      },
      "engines": {
        "node": ">=6.9.0"
      }
    }
  }
}

{
  "name": "sample-babel-types-identifier",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of @babel/types.identifier",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "@babel/types": "7.29.8"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @babel/types.identifier in pkg:npm/%40babel/types@7.29.8",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40babel/types@7.29.8"
  ],
  "symbols": [
    "@babel/types.identifier"
  ]
}

const t = require('@babel/types');

/**
 * Creates an AST Identifier node.
 * @param {string} name
 * @returns {object}
 */
function createIdentifier(name) {
  return t.identifier(name);
}

/**
 * Checks if a string is a valid JavaScript identifier.
 * @param {string} name
 * @returns {boolean}
 */
function isValidIdentifierName(name) {
  return t.isValidIdentifier(name);
}

/**
 * Checks if a node is an Identifier, optionally matching properties.
 * @param {object} node
 * @param {object} [opts]
 * @returns {boolean}
 */
function isIdentifierNode(node, opts) {
  return t.isIdentifier(node, opts);
}

/**
 * Asserts that a node is an Identifier, throwing if not.
 * @param {object} node
 * @param {object} [opts]
 */
function assertIdentifierNode(node, opts) {
  t.assertIdentifier(node, opts);
}

/**
 * Creates a VariableDeclaration AST node using an Identifier for the binding.
 * @param {string} kind
 * @param {string} name
 * @param {object} [init]
 * @returns {object}
 */
function createVariableWithIdentifier(kind, name, init) {
  const id = t.identifier(name);
  const declarator = t.variableDeclarator(id, init);
  return t.variableDeclaration(kind, [declarator]);
}

/**
 * Creates a MemberExpression AST node using an Identifier for the property.
 * @param {object} object
 * @param {string|object} property
 * @param {boolean} [computed=false]
 * @returns {object}
 */
function createMemberExpression(object, property, computed = false) {
  const propNode = typeof property === 'string' ? t.identifier(property) : property;
  return t.memberExpression(object, propNode, computed);
}

/**
 * Clones an Identifier AST node.
 * @param {object} node
 * @returns {object}
 */
function cloneIdentifier(node) {
  return t.cloneNode(node);
}

module.exports = {
  t,
  createIdentifier,
  isValidIdentifierName,
  isIdentifierNode,
  assertIdentifierNode,
  createVariableWithIdentifier,
  createMemberExpression,
  cloneIdentifier,
};

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

const require = createRequire(import.meta.url);
const {
  t,
  createIdentifier,
  isValidIdentifierName,
  isIdentifierNode,
  assertIdentifierNode,
  createVariableWithIdentifier,
  createMemberExpression,
  cloneIdentifier,
} = require('../src/index.js');

async function runContract() {
  // 1. types.identifier creates an Identifier AST node with the specified name string and type 'Identifier'
  const idNode = createIdentifier('myVar');
  assert.strictEqual(idNode.type, 'Identifier');
  assert.strictEqual(idNode.name, 'myVar');

  const anotherId = t.identifier('counter');
  assert.strictEqual(anotherId.type, 'Identifier');
  assert.strictEqual(anotherId.name, 'counter');

  // 2. types.isIdentifier returns true for Identifier nodes with optional name matching and false for non-Identifier nodes
  assert.strictEqual(isIdentifierNode(idNode), true);
  assert.strictEqual(isIdentifierNode(idNode, { name: 'myVar' }), true);
  assert.strictEqual(isIdentifierNode(idNode, { name: 'otherVar' }), false);

  const numNode = t.numericLiteral(123);
  assert.strictEqual(isIdentifierNode(numNode), false);
  assert.strictEqual(isIdentifierNode(null), false);
  assert.strictEqual(isIdentifierNode(undefined), false);

  // 3. types.assertIdentifier succeeds for valid Identifier nodes and throws an Error for non-Identifier nodes
  assertIdentifierNode(idNode);
  assertIdentifierNode(idNode, { name: 'myVar' });
  assert.throws(
    () => assertIdentifierNode(numNode),
    (err) => err instanceof Error,
    'assertIdentifier on non-Identifier node must throw'
  );
  assert.throws(
    () => assertIdentifierNode(idNode, { name: 'wrongName' }),
    (err) => err instanceof Error,
    'assertIdentifier with mismatching name option must throw'
  );

  // 4. types.isValidIdentifier correctly validates JavaScript identifier names
  assert.strictEqual(isValidIdentifierName('validIdent'), true);
  assert.strictEqual(isValidIdentifierName('$dollarSign'), true);
  assert.strictEqual(isValidIdentifierName('_underscore'), true);
  assert.strictEqual(isValidIdentifierName('123invalid'), false);
  assert.strictEqual(isValidIdentifierName('class'), false);
  assert.strictEqual(isValidIdentifierName('const'), false);

  // 5. Identifier nodes created with types.identifier integrate into larger AST constructs like VariableDeclarator and MemberExpression
  const varDecl = createVariableWithIdentifier('const', 'result', t.numericLiteral(42));
  assert.strictEqual(varDecl.type, 'VariableDeclaration');
  assert.strictEqual(varDecl.kind, 'const');
  assert.strictEqual(varDecl.declarations.length, 1);
  assert.strictEqual(varDecl.declarations[0].type, 'VariableDeclarator');
  assert.strictEqual(varDecl.declarations[0].id.type, 'Identifier');
  assert.strictEqual(varDecl.declarations[0].id.name, 'result');
  assert.strictEqual(varDecl.declarations[0].init.type, 'NumericLiteral');
  assert.strictEqual(varDecl.declarations[0].init.value, 42);

  const memberExpr = createMemberExpression(idNode, 'prop', false);
  assert.strictEqual(memberExpr.type, 'MemberExpression');
  assert.strictEqual(memberExpr.object, idNode);
  assert.strictEqual(memberExpr.property.type, 'Identifier');
  assert.strictEqual(memberExpr.property.name, 'prop');
  assert.strictEqual(memberExpr.computed, false);

  // 6. types.cloneNode produces an independent equivalent copy of an Identifier node
  const cloned = cloneIdentifier(idNode);
  assert.notStrictEqual(cloned, idNode, 'cloned node should have separate object identity');
  assert.strictEqual(cloned.type, 'Identifier');
  assert.strictEqual(cloned.name, 'myVar');
  assert.strictEqual(t.isNodesEquivalent(cloned, idNode), true);

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

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