shebang-command 2.0.0

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/shebang-command@2.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/shebang-command@2.0.0
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:sha256:6aadd00b3d9fa7db102d9d98a4d286691aa24793ffe8e34dcad8faf18eb441e0","constraints":{"executionContext":"node"},"contract":["shebangCommand(str) extracts command from /usr/bin/env shebang","shebangCommand(str) extracts command from direct binary path shebang","shebangCommand(str) extracts command and arguments from direct path shebang","shebangCommand(str) returns null when string does not contain a shebang","shebangCommand(str) returns null on empty string or undefined input"],"goal":"verify pkg:npm/shebang-command@2.0.0","kind":"HOW","packages":["pkg:npm/shebang-command@2.0.0"],"schemaVersion":1},"contractCommand":["node","test/contract.js"],"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/shebang-command@2.0.0"],"schemaVersion":1,"subject":"pkg:npm/shebang-command@2.0.0","verifierAdapter":"node-typescript@1"}

'use strict';

const shebangCommand = require('shebang-command');

function getShebangCommand(str) {
  return shebangCommand(str);
}

module.exports = {
  getShebangCommand,
};

{
  "name": "sample-2612274706",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-2612274706",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "shebang-command": "2.0.0"
      }
    },
    "node_modules/shebang-command": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/shebang-command/-/shebang-command-2.0.0.tgz",
      "integrity": "sha512-kHxr2zZpYtdmrN1qDjrrX/Z1rR1kG8Dx+gkpK1G4eXmvXswmcE1hTWBWYUzlraYw1/yZp6YuDY77YtvbN0dmDA==",
      "license": "MIT",
      "dependencies": {
        "shebang-regex": "^3.0.0"
      },
      "engines": {
        "node": ">=8"
      }
    },
    "node_modules/shebang-regex": {
      "version": "3.0.0",
      "resolved": "https://registry.npmjs.org/shebang-regex/-/shebang-regex-3.0.0.tgz",
      "integrity": "sha512-7++dFhtcx3353uBaq8DDR4NuxBetBzC7ZQOhmTQInHEd6bSrXdiEyzCvG07Z44UYdLShWUyXt5M/yhz8ekcb1A==",
      "license": "MIT",
      "engines": {
        "node": ">=8"
      }
    }
  }
}

{
  "name": "sample-2612274706",
  "version": "1.0.0",
  "description": "Minimal sample verifying shebang-command@2.0.0",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "keywords": [],
  "author": "",
  "license": "MIT-0",
  "dependencies": {
    "shebang-command": "2.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/shebang-command@2.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/shebang-command@2.0.0"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

'use strict';

const assert = require('assert');
const shebangCommand = require('shebang-command');
const { getShebangCommand } = require('../index.js');

function runContract() {
  // 1. extracts command from /usr/bin/env shebang
  const envNode = shebangCommand('#!/usr/bin/env node');
  assert.strictEqual(envNode, 'node');
  assert.strictEqual(getShebangCommand('#!/usr/bin/env node'), 'node');

  // 2. extracts command from direct binary path shebang
  const directBash = shebangCommand('#!/bin/bash');
  assert.strictEqual(directBash, 'bash');
  assert.strictEqual(getShebangCommand('#!/bin/bash'), 'bash');

  // 3. extracts command with argument from direct binary path
  const pythonWithArg = shebangCommand('#!/usr/bin/python -u');
  assert.strictEqual(pythonWithArg, 'python -u');
  assert.strictEqual(getShebangCommand('#!/usr/bin/python -u'), 'python -u');

  // 4. returns null when string has no shebang
  assert.strictEqual(shebangCommand('console.log("hello")'), null);
  assert.strictEqual(getShebangCommand('console.log("hello")'), null);

  // 5. returns null on empty string or undefined
  assert.strictEqual(shebangCommand(''), null);
  assert.strictEqual(shebangCommand(), null);

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

runContract();