@isaacs/brace-expansion 5.0.1: expand

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 expand in pkg:npm/%40isaacs/brace-expansion@5.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40isaacs/brace-expansion@5.0.1
Demonstrate these symbols/APIs:
  - expand
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:beff9f0e497924c7a2c39e39d4349578282820afc79973b263065f424223b8e5","constraints":{"executionContext":"node"},"contract":["assert expand expands comma-separated alternatives and sequential brace sets","assert expand expands numeric and alphabetical ranges with steps and zero padding","assert expand expands nested braces and empty alternatives","assert expand respects max option to cap total expansions","assert expand handles unexpanded strings and escaped braces"],"goal":"verify expand in pkg:npm/%40isaacs/brace-expansion@5.0.1","kind":"HOW","packages":["pkg:npm/%40isaacs/brace-expansion@5.0.1"],"schemaVersion":1,"symbols":["expand"]},"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/%40isaacs/brace-expansion@5.0.1"],"schemaVersion":1,"subject":"pkg:npm/%40isaacs/brace-expansion@5.0.1","symbols":["expand"],"verifierAdapter":"node-typescript@1"}

const { expand, EXPANSION_MAX } = require('@isaacs/brace-expansion');

/**
 * Expands a brace pattern into an array of resulting strings.
 *
 * @param {string} pattern - Pattern containing braces to expand.
 * @param {Object} [options] - Expansion options (e.g. { max: 100 }).
 * @returns {string[]} Array of expanded strings.
 */
function expandPattern(pattern, options) {
  return expand(pattern, options);
}

module.exports = {
  expand,
  expandPattern,
  EXPANSION_MAX,
};

{
  "name": "sample-brace-expansion",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-brace-expansion",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@isaacs/brace-expansion": "5.0.1"
      }
    },
    "node_modules/@isaacs/balanced-match": {
      "version": "4.0.1",
      "resolved": "https://registry.npmjs.org/@isaacs/balanced-match/-/balanced-match-4.0.1.tgz",
      "integrity": "sha512-yzMTt9lEb8Gv7zRioUilSglI0c0smZ9k5D65677DLWLtWJaXIS3CqcGyUFByYKlnUj6TkjLVs54fBl6+TiGQDQ==",
      "license": "MIT",
      "engines": {
        "node": "20 || >=22"
      }
    },
    "node_modules/@isaacs/brace-expansion": {
      "version": "5.0.1",
      "resolved": "https://registry.npmjs.org/@isaacs/brace-expansion/-/brace-expansion-5.0.1.tgz",
      "integrity": "sha512-WMz71T1JS624nWj2n2fnYAuPovhv7EUhk69R6i9dsVyzxt5eM3bjwvgk9L+APE1TRscGysAVMANkB0jh0LQZrQ==",
      "license": "MIT",
      "dependencies": {
        "@isaacs/balanced-match": "^4.0.1"
      },
      "engines": {
        "node": "20 || >=22"
      }
    }
  }
}

{
  "name": "sample-brace-expansion",
  "version": "1.0.0",
  "description": "Clean-room sample verifying pkg:npm/@isaacs/brace-expansion@5.0.1 functionality",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "@isaacs/brace-expansion": "5.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify expand in pkg:npm/%40isaacs/brace-expansion@5.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40isaacs/brace-expansion@5.0.1"
  ],
  "symbols": [
    "expand"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import { expand } from '@isaacs/brace-expansion';
import { expandPattern, EXPANSION_MAX } from '../index.js';

// 1. Expand comma-separated alternatives and sequential brace sets
{
  const result = expand('file-{a,b,c}.jpg');
  assert.deepStrictEqual(
    result,
    ['file-a.jpg', 'file-b.jpg', 'file-c.jpg'],
    'expand must expand comma-separated sets into individual string elements'
  );

  const sequential = expandPattern('{a,b}{1,2}');
  assert.deepStrictEqual(
    sequential,
    ['a1', 'a2', 'b1', 'b2'],
    'expand must expand sequential brace sets'
  );

  const repeated = expand('-v{,,}');
  assert.deepStrictEqual(
    repeated,
    ['-v', '-v', '-v'],
    'expand must handle empty alternatives in comma-separated sets'
  );
}

// 2. Expand numeric and alphabetical ranges with steps and zero padding
{
  const numRange = expandPattern('file{0..2}.jpg');
  assert.deepStrictEqual(
    numRange,
    ['file0.jpg', 'file1.jpg', 'file2.jpg'],
    'expand must expand ascending numeric range'
  );

  const reverseRange = expandPattern('file{2..0}.jpg');
  assert.deepStrictEqual(
    reverseRange,
    ['file2.jpg', 'file1.jpg', 'file0.jpg'],
    'expand must expand descending numeric range'
  );

  const steppedNumRange = expandPattern('file{0..4..2}.jpg');
  assert.deepStrictEqual(
    steppedNumRange,
    ['file0.jpg', 'file2.jpg', 'file4.jpg'],
    'expand must expand numeric range with custom step increment'
  );

  const alphaRange = expandPattern('file-{a..c}.jpg');
  assert.deepStrictEqual(
    alphaRange,
    ['file-a.jpg', 'file-b.jpg', 'file-c.jpg'],
    'expand must expand alphabetical range'
  );

  const steppedAlphaRange = expandPattern('file-{a..e..2}.jpg');
  assert.deepStrictEqual(
    steppedAlphaRange,
    ['file-a.jpg', 'file-c.jpg', 'file-e.jpg'],
    'expand must expand alphabetical range with step increment'
  );

  const paddedRange = expandPattern('file{00..10..5}.jpg');
  assert.deepStrictEqual(
    paddedRange,
    ['file00.jpg', 'file05.jpg', 'file10.jpg'],
    'expand must preserve zero padding in numeric ranges'
  );
}

// 3. Expand nested braces and empty alternatives
{
  const nested = expandPattern('{{A..C},{a..c}}');
  assert.deepStrictEqual(
    nested,
    ['A', 'B', 'C', 'a', 'b', 'c'],
    'expand must expand nested range sets'
  );

  const nestedComplex = expandPattern('ppp{,config,oe{,conf}}');
  assert.deepStrictEqual(
    nestedComplex,
    ['ppp', 'pppconfig', 'pppoe', 'pppoeconf'],
    'expand must expand nested sets with empty choices'
  );
}

// 4. Respect max option to cap total expansions
{
  assert.strictEqual(EXPANSION_MAX, 100000, 'EXPANSION_MAX default must be 100000');

  const limited = expandPattern('{1..100}{1..100}', { max: 10 });
  assert.strictEqual(
    limited.length,
    10,
    'expand must respect max option to limit returned expansions'
  );
}

// 5. Handle unexpanded strings and escaped braces
{
  const unexpanded = expandPattern('plain-string');
  assert.deepStrictEqual(
    unexpanded,
    ['plain-string'],
    'expand returns single element array when no braces are present'
  );

  const emptyString = expandPattern('');
  assert.deepStrictEqual(
    emptyString,
    [],
    'expand returns empty array for empty string input'
  );

  const dollarBrace = expandPattern('${a,b}');
  assert.deepStrictEqual(
    dollarBrace,
    ['${a,b}'],
    'expand does not expand ${...} expressions for shell compatibility'
  );
}

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