graceful-fs 4.2.11: promises

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 graceful-fs.promises in pkg:npm/graceful-fs@4.2.11
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/graceful-fs@4.2.11
Demonstrate these symbols/APIs:
  - graceful-fs.promises

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:sha256:187ceafa86e98fc3d2c0cd551617bcfe5d732d2d6c2d13cf03ecd2ad7d0843ab","contract":["promises property on graceful-fs provides promise-based filesystem methods","promises.writeFile asynchronously writes data and promises.readFile reads back string and buffer content","promises.readFile rejects with ENOENT when reading a non-existent file path","promises.mkdir creates directories recursively and promises.readdir lists directory entries","promises.stat retrieves file statistics and verifies file type","promises.unlink deletes files and promises.rm removes directory trees"],"goal":"verify graceful-fs.promises in pkg:npm/graceful-fs@4.2.11","kind":"HOW","packages":["pkg:npm/graceful-fs@4.2.11"],"schemaVersion":1,"symbols":["graceful-fs.promises"]},"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/graceful-fs@4.2.11"],"schemaVersion":1,"subject":"pkg:npm/graceful-fs@4.2.11","symbols":["graceful-fs.promises"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-graceful-fs-promises",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-graceful-fs-promises",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "graceful-fs": "4.2.11"
      }
    },
    "node_modules/graceful-fs": {
      "version": "4.2.11",
      "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.11.tgz",
      "integrity": "sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==",
      "license": "ISC"
    }
  }
}

{
  "name": "sample-graceful-fs-promises",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of graceful-fs.promises in pkg:npm/graceful-fs@4.2.11",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "graceful-fs": "4.2.11"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify graceful-fs.promises in pkg:npm/graceful-fs@4.2.11",
  "kind": "HOW",
  "packages": [
    "pkg:npm/graceful-fs@4.2.11"
  ],
  "symbols": [
    "graceful-fs.promises"
  ]
}

'use strict';

const gracefulFs = require('graceful-fs');

/**
 * Access the promises-based filesystem API provided by graceful-fs.
 * @returns {object} The fs.promises API object.
 */
function getPromisesFs() {
  return gracefulFs.promises;
}

/**
 * Write data to a file asynchronously using graceful-fs.promises.
 * @param {string} filePath - Path to the file.
 * @param {string|Buffer} data - Data to write.
 * @param {string|object} [options] - Encoding or options object.
 * @returns {Promise<void>}
 */
async function writeFileAsync(filePath, data, options = 'utf8') {
  return gracefulFs.promises.writeFile(filePath, data, options);
}

/**
 * Read data from a file asynchronously using graceful-fs.promises.
 * @param {string} filePath - Path to the file.
 * @param {string|object} [options] - Encoding or options object.
 * @returns {Promise<string|Buffer>}
 */
async function readFileAsync(filePath, options = 'utf8') {
  return gracefulFs.promises.readFile(filePath, options);
}

/**
 * Create a directory asynchronously using graceful-fs.promises.
 * @param {string} dirPath - Path to directory to create.
 * @param {object} [options] - mkdir options (e.g. recursive).
 * @returns {Promise<string|undefined>}
 */
async function makeDirectoryAsync(dirPath, options = { recursive: true }) {
  return gracefulFs.promises.mkdir(dirPath, options);
}

/**
 * Read contents of a directory asynchronously using graceful-fs.promises.
 * @param {string} dirPath - Path to directory.
 * @returns {Promise<string[]>} List of file names.
 */
async function readDirectoryAsync(dirPath) {
  return gracefulFs.promises.readdir(dirPath);
}

/**
 * Retrieve file metadata asynchronously using graceful-fs.promises.
 * @param {string} targetPath - Path to file or directory.
 * @returns {Promise<object>}
 */
async function getFileStatsAsync(targetPath) {
  return gracefulFs.promises.stat(targetPath);
}

/**
 * Remove a file asynchronously using graceful-fs.promises.
 * @param {string} filePath - Path to file to delete.
 * @returns {Promise<void>}
 */
async function removeFileAsync(filePath) {
  return gracefulFs.promises.unlink(filePath);
}

/**
 * Remove a directory tree asynchronously using graceful-fs.promises.
 * @param {string} dirPath - Path to directory to remove.
 * @returns {Promise<void>}
 */
async function removeDirectoryAsync(dirPath) {
  return gracefulFs.promises.rm(dirPath, { recursive: true, force: true });
}

module.exports = {
  gracefulFs,
  getPromisesFs,
  writeFileAsync,
  readFileAsync,
  makeDirectoryAsync,
  readDirectoryAsync,
  getFileStatsAsync,
  removeFileAsync,
  removeDirectoryAsync,
};

import assert from 'node:assert/strict';
import path from 'node:path';
import os from 'node:os';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const {
  gracefulFs,
  getPromisesFs,
  writeFileAsync,
  readFileAsync,
  makeDirectoryAsync,
  readDirectoryAsync,
  getFileStatsAsync,
  removeFileAsync,
  removeDirectoryAsync,
} = require('../src/index.js');

async function runContract() {
  const testRoot = path.join(
    os.tmpdir(),
    `gfs-promises-contract-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`
  );
  await makeDirectoryAsync(testRoot, { recursive: true });

  try {
    // 1. Module export and promises property verification
    assert.ok(gracefulFs, 'gracefulFs module should be defined');
    assert.strictEqual(typeof gracefulFs.promises, 'object', 'graceful-fs should export promises object');
    assert.strictEqual(getPromisesFs(), gracefulFs.promises, 'getPromisesFs should return gracefulFs.promises');
    assert.strictEqual(typeof gracefulFs.promises.readFile, 'function', 'promises.readFile should be a function');
    assert.strictEqual(typeof gracefulFs.promises.writeFile, 'function', 'promises.writeFile should be a function');
    assert.strictEqual(typeof gracefulFs.promises.mkdir, 'function', 'promises.mkdir should be a function');
    assert.strictEqual(typeof gracefulFs.promises.readdir, 'function', 'promises.readdir should be a function');
    assert.strictEqual(typeof gracefulFs.promises.stat, 'function', 'promises.stat should be a function');
    assert.strictEqual(typeof gracefulFs.promises.unlink, 'function', 'promises.unlink should be a function');
    assert.strictEqual(typeof gracefulFs.promises.rm, 'function', 'promises.rm should be a function');

    // 2. Asynchronous writeFile and readFile with string and buffer encodings
    {
      const filePath = path.join(testRoot, 'payload.txt');
      const payload = 'Graceful filesystem promise-based content';
      await writeFileAsync(filePath, payload, 'utf8');

      const readText = await readFileAsync(filePath, 'utf8');
      assert.strictEqual(readText, payload, 'Read text should match written payload');

      const readBuffer = await readFileAsync(filePath, null);
      assert.ok(Buffer.isBuffer(readBuffer), 'Reading with null encoding should return a Buffer');
      assert.strictEqual(readBuffer.toString('utf8'), payload, 'Buffer content should match payload');
    }

    // 3. Rejection with ENOENT on non-existent file
    {
      const missingPath = path.join(testRoot, 'does_not_exist.txt');
      let caughtError = null;
      try {
        await readFileAsync(missingPath, 'utf8');
      } catch (err) {
        caughtError = err;
      }
      assert.ok(caughtError !== null, 'Reading non-existent file should reject');
      assert.strictEqual(caughtError.code, 'ENOENT', 'Error code should be ENOENT');
    }

    // 4. Directory creation and directory listing
    {
      const subDir = path.join(testRoot, 'nested', 'level');
      await makeDirectoryAsync(subDir, { recursive: true });

      const fileA = path.join(subDir, 'fileA.txt');
      const fileB = path.join(subDir, 'fileB.txt');
      await writeFileAsync(fileA, 'dataA');
      await writeFileAsync(fileB, 'dataB');

      const entries = await readDirectoryAsync(subDir);
      assert.ok(Array.isArray(entries), 'readdir should return an array');
      assert.ok(entries.includes('fileA.txt'), 'Directory should include fileA.txt');
      assert.ok(entries.includes('fileB.txt'), 'Directory should include fileB.txt');
    }

    // 5. File stats retrieval and type verification
    {
      const statsFile = path.join(testRoot, 'stats_test.txt');
      const content = '1234567890';
      await writeFileAsync(statsFile, content, 'utf8');

      const stats = await getFileStatsAsync(statsFile);
      assert.ok(stats.isFile(), 'stat should identify path as a file');
      assert.strictEqual(stats.size, 10, 'stat.size should match byte count');
    }

    // 6. File deletion and recursive directory removal
    {
      const deleteDir = path.join(testRoot, 'to_remove');
      await makeDirectoryAsync(deleteDir, { recursive: true });
      const deleteFile = path.join(deleteDir, 'temp.txt');
      await writeFileAsync(deleteFile, 'temp content', 'utf8');

      await removeFileAsync(deleteFile);
      let fileMissing = false;
      try {
        await getFileStatsAsync(deleteFile);
      } catch (err) {
        fileMissing = err.code === 'ENOENT';
      }
      assert.ok(fileMissing, 'File should be removed by unlink');

      await removeDirectoryAsync(deleteDir);
      let dirMissing = false;
      try {
        await getFileStatsAsync(deleteDir);
      } catch (err) {
        dirMissing = err.code === 'ENOENT';
      }
      assert.ok(dirMissing, 'Directory tree should be removed by rm');
    }

    console.log('All graceful-fs.promises contract assertions passed successfully.');
  } finally {
    try {
      await removeDirectoryAsync(testRoot);
    } catch (_) {}
  }
}

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