pkg-dir 4.2.0: find root directory of a node package using pkg-dir

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: find root directory of a node package using pkg-dir
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pkg-dir@4.2.0
Demonstrate these symbols/APIs:
  - pkgDir
  - pkgDir.sync

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:sha256:06505393dbe6dd4751911f3dad9231bf93f91dd33925b869305674cd70ced682","contract":["pkgDir asynchronously finds the root directory of a Node.js package containing package.json from a nested directory","pkgDir.sync synchronously finds the root directory of a Node.js package containing package.json from a nested directory","pkgDir resolves to undefined when no package.json exists in the directory hierarchy","pkgDir.sync returns undefined when no package.json exists in the directory hierarchy","pkgDir and pkgDir.sync resolve the current package root when cwd is omitted"],"goal":"find root directory of a node package using pkg-dir","kind":"HOW","packages":["pkg:npm/pkg-dir@4.2.0"],"schemaVersion":1,"symbols":["pkgDir","pkgDir.sync"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/pkg-dir@4.2.0"],"schemaVersion":1,"subject":"pkg:npm/pkg-dir@4.2.0","symbols":["pkgDir","pkgDir.sync"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-pkg-dir",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pkg-dir",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "pkg-dir": "4.2.0"
      }
    },
    "node_modules/find-up": {
      "version": "4.1.0",
      "resolved": "https://registry.npmjs.org/find-up/-/find-up-4.1.0.tgz",
      "integrity": "sha512-PpOwAdQ/YlXQ2vj8a3h8IipDuYRi3wceVQQGYWxNINccq40Anw7BlsEXCMbt1Zt+OLA6Fq9suIpIWD0OsnISlw==",
      "license": "MIT",
      "dependencies": {
        "locate-path": "^5.0.0",
        "path-exists": "^4.0.0"
      },
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/locate-path": {
      "version": "5.0.0",
      "resolved": "https://registry.npmjs.org/locate-path/-/locate-path-5.0.0.tgz",
      "integrity": "sha512-t7hw9pI+WvuwNJXwk5zVHpyhIqzg2qTlklJOf0mVxGSbe3Fp2VieZcduNYjaLDoy6p9uGpQEGWG87WpMKlNq8g==",
      "license": "MIT",
      "dependencies": {
        "p-locate": "^4.1.0"
      },
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/p-limit": {
      "version": "2.3.0",
      "resolved": "https://registry.npmjs.org/p-limit/-/p-limit-2.3.0.tgz",
      "integrity": "sha512-//88mFWSJx8lxCzwdAABTJL2MyWB12+eIY7MDL2SqLmAkeKU9qxRvWuSyTjm3FUmpBEMuFfckAIqEaVGUDxb6w==",
      "license": "MIT",
      "dependencies": {
        "p-try": "^2.0.0"
      },
      "engines": {
        "node": ">=6"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/p-locate": {
      "version": "4.1.0",
      "resolved": "https://registry.npmjs.org/p-locate/-/p-locate-4.1.0.tgz",
      "integrity": "sha512-R79ZZ/0wAxKGu3oYMlz8jy/kbhsNrS7SKZ7PxEHBgJ5+F2mtFW2fK2cOtBh1cHYkQsbzFV7I+EoRKe6Yt0oK7A==",
      "license": "MIT",
      "dependencies": {
        "p-limit": "^2.2.0"
      },
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/p-try": {
      "version": "2.2.0",
      "resolved": "https://registry.npmjs.org/p-try/-/p-try-2.2.0.tgz",
      "integrity": "sha512-R4nPAVTAU0B9D35/Gk3uJf/7XYbQcyohSKdvAxIRSNghFl4e71hVoGnBNQz9cWaXxO2I10KTC+3jMdvvoKw6dQ==",
      "license": "MIT",
      "engines": {
        "node": ">=6"
      }
    },
    "node_modules/path-exists": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz",
      "integrity": "sha512-ak9Qy5Q7jYb2Wwcey5Fpvg2KoAc/ZIhLSLOSBmRmygPsGwkVVt0fZa0qrtMz+m6tJTAHfZQ8FnmB4MG4LWy7/w==",
      "license": "MIT",
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/pkg-dir": {
      "version": "4.2.0",
      "resolved": "https://registry.npmjs.org/pkg-dir/-/pkg-dir-4.2.0.tgz",
      "integrity": "sha512-HRDzbaKjC+AOWVXxAU/x54COGeIv9eb+6CkDSQoNTt4XyWoIJvuPsXizxu/Fr23EiekbtZwmh1IcIG/l/a10GQ==",
      "license": "MIT",
      "dependencies": {
        "find-up": "^4.0.0"
      },
      "engines": {
        "node": ">=8"
      }
    }
  }
}

{
  "name": "sample-pkg-dir",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "pkg-dir": "4.2.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "find root directory of a node package using pkg-dir",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pkg-dir@4.2.0"
  ],
  "symbols": [
    "pkgDir",
    "pkgDir.sync"
  ]
}

import pkgDir from 'pkg-dir';

/**
 * Asynchronously finds the root directory of a Node.js project or npm package.
 * @param {string} [cwd] - Directory to start searching from (defaults to process.cwd()).
 * @returns {Promise<string | undefined>}
 */
export async function findPackageRoot(cwd) {
  return await pkgDir(cwd);
}

/**
 * Synchronously finds the root directory of a Node.js project or npm package.
 * @param {string} [cwd] - Directory to start searching from (defaults to process.cwd()).
 * @returns {string | undefined}
 */
export function findPackageRootSync(cwd) {
  return pkgDir.sync(cwd);
}

export { pkgDir };

import assert from 'node:assert/strict';
import fs from 'node:fs';
import path from 'node:path';
import os from 'node:os';
import pkgDir from 'pkg-dir';
import { findPackageRoot, findPackageRootSync } from '../src/index.mjs';

const tempRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'csx-pkg-dir-contract-'));
const projectDir = path.join(tempRoot, 'nested-project');
const deepDir = path.join(projectDir, 'src', 'features', 'deep');
const emptyDir = path.join(tempRoot, 'isolated-empty', 'deep');

try {
  // Create nested project directory structure with package.json
  fs.mkdirSync(deepDir, { recursive: true });
  fs.writeFileSync(
    path.join(projectDir, 'package.json'),
    JSON.stringify({ name: 'nested-dummy-pkg', version: '1.0.0' }, null, 2),
    'utf8'
  );

  // Create isolated empty directory structure with no package.json
  fs.mkdirSync(emptyDir, { recursive: true });

  const canonicalProjectDir = fs.realpathSync(projectDir);

  // Contract 1: pkgDir asynchronously finds the root directory of a Node.js package containing package.json from a nested directory
  {
    const rootFromDeep = await pkgDir(deepDir);
    assert.notEqual(rootFromDeep, undefined, 'pkgDir should find root from deep subdirectory');
    assert.equal(fs.realpathSync(rootFromDeep), canonicalProjectDir);

    const rootFromProject = await pkgDir(projectDir);
    assert.notEqual(rootFromProject, undefined, 'pkgDir should find root from project directory');
    assert.equal(fs.realpathSync(rootFromProject), canonicalProjectDir);
  }

  // Contract 2: pkgDir.sync synchronously finds the root directory of a Node.js package containing package.json from a nested directory
  {
    const rootSyncFromDeep = pkgDir.sync(deepDir);
    assert.notEqual(rootSyncFromDeep, undefined, 'pkgDir.sync should find root from deep subdirectory');
    assert.equal(fs.realpathSync(rootSyncFromDeep), canonicalProjectDir);

    const rootSyncFromProject = pkgDir.sync(projectDir);
    assert.notEqual(rootSyncFromProject, undefined, 'pkgDir.sync should find root from project directory');
    assert.equal(fs.realpathSync(rootSyncFromProject), canonicalProjectDir);
  }

  // Contract 3: pkgDir resolves to undefined when no package.json exists in the directory hierarchy
  {
    const noRootAsync = await pkgDir(emptyDir);
    assert.equal(noRootAsync, undefined, 'pkgDir should resolve undefined when no package.json is present');
  }

  // Contract 4: pkgDir.sync returns undefined when no package.json exists in the directory hierarchy
  {
    const noRootSync = pkgDir.sync(emptyDir);
    assert.equal(noRootSync, undefined, 'pkgDir.sync should return undefined when no package.json is present');
  }

  // Contract 5: pkgDir and pkgDir.sync resolve the current package root when cwd is omitted
  {
    const currentRootAsync = await pkgDir();
    assert.notEqual(currentRootAsync, undefined, 'pkgDir() should find current project root');
    assert.equal(typeof currentRootAsync, 'string');
    assert.equal(fs.existsSync(path.join(currentRootAsync, 'package.json')), true);

    const currentRootSync = pkgDir.sync();
    assert.notEqual(currentRootSync, undefined, 'pkgDir.sync() should find current project root');
    assert.equal(typeof currentRootSync, 'string');
    assert.equal(currentRootAsync, currentRootSync);
    assert.equal(fs.existsSync(path.join(currentRootSync, 'package.json')), true);

    // Helper functions from src/index.mjs
    const helperAsync = await findPackageRoot(deepDir);
    assert.equal(fs.realpathSync(helperAsync), canonicalProjectDir);

    const helperSync = findPackageRootSync(deepDir);
    assert.equal(fs.realpathSync(helperSync), canonicalProjectDir);
  }

  console.log('All pkg-dir contract tests passed successfully.');
} finally {
  try {
    fs.rmSync(tempRoot, { recursive: true, force: true });
  } catch {
    // Ignore cleanup error
  }
}