cac 6.7.14: parse command line options with cac

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: parse command line options with cac
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/cac@6.7.14
Demonstrate these symbols/APIs:
  - cac
  - cac.command
  - cac.parse

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:sha256:7f8693f0ec9174ab44d913606f33803ee8750cca3fd52f80c790b4f479239d5a","contract":["cac creates a CLI instance with the specified name","cac.command registers commands with positional arguments and options with default values","cac.parse parses arguments for matched command and extracts positional args and option values","cac.parse applies default option values when options are not provided"],"goal":"parse command line options with cac","kind":"HOW","packages":["pkg:npm/cac@6.7.14"],"schemaVersion":1,"symbols":["cac","cac.command","cac.parse"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","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/cac@6.7.14"],"schemaVersion":1,"subject":"pkg:npm/cac@6.7.14","symbols":["cac","cac.command","cac.parse"],"verifierAdapter":"node-typescript@1"}

const { cac } = require('cac');

/**
 * Creates and configures a CLI instance with commands and options.
 * @param {string} [name='cli-app'] - Name of the CLI application.
 * @returns {import('cac').CAC} Configured CAC instance.
 */
function createCli(name = 'cli-app') {
  const cli = cac(name);

  cli
    .command('build <entry>', 'Build the project from entry point')
    .option('--target <target>', 'Target output environment (e.g. node, browser)', {
      default: 'node',
    })
    .option('--minify', 'Minify the generated output bundle', {
      default: false,
    });

  cli
    .command('serve', 'Start local development server')
    .option('--port <port>', 'Port to listen on', {
      default: 3000,
    });

  return cli;
}

/**
 * Parses command line arguments using a CAC CLI instance.
 * @param {import('cac').CAC} cli - CAC instance.
 * @param {string[]} argv - Array of command line arguments (e.g. process.argv).
 * @param {object} [options] - CAC parse options (e.g. { run: false }).
 * @returns {import('cac').ParsedArgv} Parsed command line arguments and options.
 */
function parseArgs(cli, argv, options = { run: false }) {
  return cli.parse(argv, options);
}

module.exports = {
  createCli,
  parseArgs,
};

{
  "name": "cac-sample",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "cac-sample",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "cac": "6.7.14"
      }
    },
    "node_modules/cac": {
      "version": "6.7.14",
      "resolved": "https://registry.npmjs.org/cac/-/cac-6.7.14.tgz",
      "integrity": "sha512-b6Ilus+c3RrdDk+JhLKUAQfzzgLEPy6wcXqS7f/xe1EETvsDP6GORG7SFuOs6cID5YkqchW/LXZbX5bc8j7ZcQ==",
      "license": "MIT",
      "engines": {
        "node": ">=8"
      }
    }
  }
}

{
  "name": "cac-sample",
  "version": "1.0.0",
  "description": "Parse command line options with cac",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "cac": "6.7.14"
  },
  "private": true,
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "parse command line options with cac",
  "kind": "HOW",
  "packages": [
    "pkg:npm/cac@6.7.14"
  ],
  "symbols": [
    "cac",
    "cac.command",
    "cac.parse"
  ]
}

const assert = require('assert');
const { cac } = require('cac');
const { createCli, parseArgs } = require('../index.js');

// 1. Direct symbol test: cac factory
const cli = cac('test-cli');
assert.strictEqual(typeof cli, 'object', 'cac() should return a CLI instance object');
assert.strictEqual(cli.name, 'test-cli', 'cli.name should match the constructor argument');

// 2. Direct symbol test: cli.command and cli.parse
cli
  .command('bundle <entry>', 'Bundle project')
  .option('--format <format>', 'Output format', { default: 'esm' })
  .option('--sourcemap', 'Generate source maps');

const parsed = cli.parse(['node', 'cli.js', 'bundle', 'src/main.js', '--format', 'cjs', '--sourcemap'], { run: false });
assert.deepStrictEqual(
  parsed.args,
  ['src/main.js'],
  'cli.parse should extract positional command argument'
);
assert.strictEqual(
  parsed.options.format,
  'cjs',
  'cli.parse should parse explicit option value'
);
assert.strictEqual(
  parsed.options.sourcemap,
  true,
  'cli.parse should parse boolean flag option'
);

// 3. Test default options with helper
const helperCli = createCli('sample-tool');
const defaultParsed = parseArgs(helperCli, ['node', 'cli.js', 'build', 'index.ts'], { run: false });

assert.deepStrictEqual(
  defaultParsed.args,
  ['index.ts'],
  'helperCli should parse entry positional argument'
);
assert.strictEqual(
  defaultParsed.options.target,
  'node',
  'helperCli should apply default option value when omitted'
);
assert.strictEqual(
  defaultParsed.options.minify,
  false,
  'helperCli should apply default boolean false when omitted'
);

// 4. Test command with custom option values
const customParsed = parseArgs(
  helperCli,
  ['node', 'cli.js', 'build', 'index.ts', '--target', 'browser', '--minify'],
  { run: false }
);
assert.strictEqual(
  customParsed.options.target,
  'browser',
  'helperCli should override default option with user value'
);
assert.strictEqual(
  customParsed.options.minify,
  true,
  'helperCli should set boolean flag to true when passed'
);

console.log('Contract assertions passed.');