@babel/types 7.29.8: isIdentifier

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.isIdentifier 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.isIdentifier
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - 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:sha256:38786eae53f85821c7443e7988ba67fc2eacef01d5a3e4e46354aebaf1818f7f","constraints":{"executionContext":"node"},"contract":["isIdentifier returns true for valid Identifier AST nodes","isIdentifier returns false for non-Identifier AST nodes, primitives, and nullish values","isIdentifier supports property filtering via match options such as name","isIdentifier correctly distinguishes identifier nodes from literal and expression nodes"],"goal":"verify @babel/types.isIdentifier in pkg:npm/%40babel/types@7.29.8","kind":"HOW","packages":["pkg:npm/%40babel/types@7.29.8"],"schemaVersion":1,"symbols":["@babel/types.isIdentifier"]},"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/%40babel/types@7.29.8"],"schemaVersion":1,"subject":"pkg:npm/%40babel/types@7.29.8","symbols":["@babel/types.isIdentifier"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-babel-types-is-identifier",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-babel-types-is-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-is-identifier",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "@babel/types": "7.29.8"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @babel/types.isIdentifier in pkg:npm/%40babel/types@7.29.8",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40babel/types@7.29.8"
  ],
  "symbols": [
    "@babel/types.isIdentifier"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import * as t from "@babel/types";

export function createIdentifier(name) {
  return t.identifier(name);
}

export function checkIsIdentifier(node, opts) {
  return t.isIdentifier(node, opts);
}

export function filterIdentifiers(nodes) {
  return nodes.filter((node) => t.isIdentifier(node));
}

export function findIdentifierByName(nodes, targetName) {
  return nodes.find((node) => t.isIdentifier(node, { name: targetName })) || null;
}

import assert from "node:assert/strict";
import * as t from "@babel/types";
import {
  createIdentifier,
  checkIsIdentifier,
  filterIdentifiers,
  findIdentifierByName
} from "../src/index.mjs";

// Test 1: isIdentifier returns true for valid Identifier AST nodes
{
  const idNode = createIdentifier("myVariable");
  assert.equal(idNode.type, "Identifier");
  assert.equal(idNode.name, "myVariable");
  assert.equal(checkIsIdentifier(idNode), true);
  assert.equal(t.isIdentifier(idNode), true);
}

// Test 2: isIdentifier returns false for non-Identifier AST nodes, primitives, and nullish values
{
  assert.equal(checkIsIdentifier(null), false);
  assert.equal(checkIsIdentifier(undefined), false);
  assert.equal(checkIsIdentifier(42), false);
  assert.equal(checkIsIdentifier("myVariable"), false);
  assert.equal(checkIsIdentifier({}), false);
  assert.equal(checkIsIdentifier({ type: "NotAnIdentifier" }), false);
}

// Test 3: isIdentifier supports property filtering via match options such as name
{
  const idFoo = createIdentifier("foo");
  const idBar = createIdentifier("bar");

  assert.equal(t.isIdentifier(idFoo, { name: "foo" }), true);
  assert.equal(t.isIdentifier(idFoo, { name: "bar" }), false);
  assert.equal(t.isIdentifier(idBar, { name: "bar" }), true);

  const list = [
    t.numericLiteral(123),
    idFoo,
    t.stringLiteral("hello"),
    idBar
  ];

  const foundFoo = findIdentifierByName(list, "foo");
  assert.notEqual(foundFoo, null);
  assert.equal(foundFoo.name, "foo");

  const foundBaz = findIdentifierByName(list, "baz");
  assert.equal(foundBaz, null);
}

// Test 4: isIdentifier correctly distinguishes identifier nodes from literal and expression nodes
{
  const numNode = t.numericLiteral(100);
  const strNode = t.stringLiteral("text");
  const binNode = t.binaryExpression("+", t.identifier("a"), t.identifier("b"));
  const callNode = t.callExpression(t.identifier("fn"), []);
  const idNode = t.identifier("result");

  const mixedNodes = [numNode, strNode, binNode, callNode, idNode];
  const identifiersOnly = filterIdentifiers(mixedNodes);

  assert.equal(identifiersOnly.length, 1);
  assert.equal(identifiersOnly[0], idNode);
  assert.equal(t.isIdentifier(numNode), false);
  assert.equal(t.isIdentifier(strNode), false);
  assert.equal(t.isIdentifier(binNode), false);
  assert.equal(t.isIdentifier(callNode), false);
  assert.equal(t.isIdentifier(idNode), true);
}

console.log("All @babel/types.isIdentifier contract tests passed successfully.");