@babel/compat-data 8.0.0

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 pkg:npm/%40babel/compat-data@8.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40babel/compat-data@8.0.0
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:sha256:791ff65aac65219a74113a4f63c0e6c61347e5bc564f71c2467cd0507c3168e5","constraints":{"executionContext":"node"},"contract":["@babel/compat-data/plugins exports compatibility mapping object containing target environment minimum versions for Babel transform plugins","@babel/compat-data/plugins contains valid target environment versions for standard ECMAScript transforms such as classes, arrow functions, and optional chaining","@babel/compat-data/native-modules exports compatibility requirements for native ES module support","@babel/compat-data/overlapping-plugins maps transform plugins to their corresponding bugfix plugin subsets","@babel/compat-data/plugin-bugfixes exports environment support versions for specific browser engine bug fixes","@babel/compat-data/package.json subpath export provides valid package metadata matching version 8.0.0","compat-data exports are accessible and identical via both CommonJS require and ES module import attributes"],"goal":"verify pkg:npm/%40babel/compat-data@8.0.0","kind":"HOW","packages":["pkg:npm/%40babel/compat-data@8.0.0"],"schemaVersion":1},"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/compat-data@8.0.0"],"schemaVersion":1,"subject":"pkg:npm/%40babel/compat-data@8.0.0","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-babel-compat-data",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-babel-compat-data",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@babel/compat-data": "8.0.0"
      }
    },
    "node_modules/@babel/compat-data": {
      "version": "8.0.0",
      "resolved": "https://registry.npmjs.org/@babel/compat-data/-/compat-data-8.0.0.tgz",
      "integrity": "sha512-DOjnob/cXOUgDOozCDeq/aK2p5y8dUIVdf6tNhEV1HQRd6I8aQ4f4fbtHRVEvb6lP3BGomrKHiS8ICAASSVQSw==",
      "license": "MIT",
      "engines": {
        "node": "^22.18.0 || >=24.11.0"
      }
    }
  }
}

{
  "name": "sample-babel-compat-data",
  "version": "1.0.0",
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "@babel/compat-data": "8.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/%40babel/compat-data@8.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40babel/compat-data@8.0.0"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import plugins from '@babel/compat-data/plugins' with { type: 'json' };
import nativeModules from '@babel/compat-data/native-modules' with { type: 'json' };
import overlappingPlugins from '@babel/compat-data/overlapping-plugins' with { type: 'json' };
import pluginBugfixes from '@babel/compat-data/plugin-bugfixes' with { type: 'json' };

const require = createRequire(import.meta.url);

// 1. @babel/compat-data/plugins exports compatibility mapping object containing target environment minimum versions for Babel transform plugins
assert.equal(typeof plugins, 'object', 'plugins export must be an object');
assert.ok(plugins !== null, 'plugins export must not be null');
assert.ok(Object.keys(plugins).length > 0, 'plugins export must contain transform mappings');

// 2. @babel/compat-data/plugins contains valid target environment versions for standard ECMAScript transforms such as classes, arrow functions, and optional chaining
assert.ok('transform-classes' in plugins, 'plugins must contain transform-classes');
assert.ok('transform-arrow-functions' in plugins, 'plugins must contain transform-arrow-functions');
assert.ok('transform-optional-chaining' in plugins, 'plugins must contain transform-optional-chaining');

const classCompat = plugins['transform-classes'];
assert.equal(typeof classCompat, 'object', 'transform-classes compat data must be an object');
assert.equal(typeof classCompat.chrome, 'string', 'transform-classes chrome version must be a string');
assert.equal(typeof classCompat.node, 'string', 'transform-classes node version must be a string');
assert.equal(typeof classCompat.firefox, 'string', 'transform-classes firefox version must be a string');
assert.equal(typeof classCompat.safari, 'string', 'transform-classes safari version must be a string');

const optionalChainingCompat = plugins['transform-optional-chaining'];
assert.equal(typeof optionalChainingCompat, 'object', 'transform-optional-chaining compat data must be an object');
assert.equal(typeof optionalChainingCompat.chrome, 'string', 'transform-optional-chaining chrome version must be a string');
assert.equal(typeof optionalChainingCompat.node, 'string', 'transform-optional-chaining node version must be a string');

// 3. @babel/compat-data/native-modules exports compatibility requirements for native ES module support
assert.equal(typeof nativeModules, 'object', 'nativeModules export must be an object');
assert.ok('es6.module' in nativeModules, 'nativeModules must include es6.module definition');
const es6Module = nativeModules['es6.module'];
assert.equal(typeof es6Module.chrome, 'string', 'es6.module chrome target must be defined');
assert.equal(typeof es6Module.node, 'string', 'es6.module node target must be defined');
assert.equal(typeof es6Module.safari, 'string', 'es6.module safari target must be defined');

// 4. @babel/compat-data/overlapping-plugins maps transform plugins to their corresponding bugfix plugin subsets
assert.equal(typeof overlappingPlugins, 'object', 'overlappingPlugins export must be an object');
assert.ok('transform-async-to-generator' in overlappingPlugins, 'overlappingPlugins must contain transform-async-to-generator');
assert.ok(Array.isArray(overlappingPlugins['transform-async-to-generator']), 'overlapping mapping must be an array of bugfix plugins');
assert.ok(
  overlappingPlugins['transform-async-to-generator'].includes('bugfix/transform-async-arrows-in-class'),
  'transform-async-to-generator must map to bugfix/transform-async-arrows-in-class'
);

// 5. @babel/compat-data/plugin-bugfixes exports environment support versions for specific browser engine bug fixes
assert.equal(typeof pluginBugfixes, 'object', 'pluginBugfixes export must be an object');
assert.ok('bugfix/transform-async-arrows-in-class' in pluginBugfixes, 'pluginBugfixes must include async arrows bugfix');
const asyncArrowsFix = pluginBugfixes['bugfix/transform-async-arrows-in-class'];
assert.equal(typeof asyncArrowsFix.chrome, 'string', 'bugfix chrome version must be defined');
assert.equal(typeof asyncArrowsFix.node, 'string', 'bugfix node version must be defined');
assert.equal(typeof asyncArrowsFix.safari, 'string', 'bugfix safari version must be defined');

// 6. @babel/compat-data/package.json subpath export provides valid package metadata matching version 8.0.0
const pkgJson = require('@babel/compat-data/package.json');
assert.equal(pkgJson.name, '@babel/compat-data', 'package name must be @babel/compat-data');
assert.equal(pkgJson.version, '8.0.0', 'package version must be 8.0.0');

// 7. compat-data exports are accessible and identical via both CommonJS require and ES module import attributes
const cjsPlugins = require('@babel/compat-data/plugins');
const cjsNativeModules = require('@babel/compat-data/native-modules');
const cjsOverlappingPlugins = require('@babel/compat-data/overlapping-plugins');
const cjsPluginBugfixes = require('@babel/compat-data/plugin-bugfixes');

assert.deepEqual(plugins, cjsPlugins, 'ESM and CJS plugins data must match identically');
assert.deepEqual(nativeModules, cjsNativeModules, 'ESM and CJS nativeModules data must match identically');
assert.deepEqual(overlappingPlugins, cjsOverlappingPlugins, 'ESM and CJS overlappingPlugins data must match identically');
assert.deepEqual(pluginBugfixes, cjsPluginBugfixes, 'ESM and CJS pluginBugfixes data must match identically');

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