read-cmd-shim 5.0.0: readCmdShim, readCmdShim.sync

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/read-cmd-shim@5.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/read-cmd-shim@5.0.0

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:e3f8f868b1791034c5f2d074d2bbef3836cf1fbe36f24cc3cac0f738a9db3091","contract":["readCmdShim(path) and readCmdShim.sync(path) extract the relative target path from a .cmd shim matching \"%~dp0\\\u003ctarget\u003e\" %*","readCmdShim(path) and readCmdShim.sync(path) extract the relative target path from a .ps1 shim matching \"$basedir/\u003ctarget\u003e\" $args","readCmdShim(path) and readCmdShim.sync(path) extract the relative target path from a Cygwin/POSIX shim matching \"$basedir/\u003ctarget\u003e\" \"$@\"","readCmdShim(path) and readCmdShim.sync(path) reject/throw an error with code 'ENOTASHIM' when the file contents do not match a cmd-shim format"],"goal":"verify pkg:npm/read-cmd-shim@5.0.0","kind":"HOW","packages":["pkg:npm/read-cmd-shim@5.0.0"],"schemaVersion":1,"symbols":["readCmdShim","readCmdShim.sync"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","runtime":"node","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/read-cmd-shim@5.0.0"],"schemaVersion":1,"subject":"pkg:npm/read-cmd-shim@5.0.0","symbols":["readCmdShim","readCmdShim.sync"],"verifierAdapter":"node-typescript@1"}

{
  "name": "verify-read-cmd-shim",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "verify-read-cmd-shim",
      "version": "1.0.0",
      "dependencies": {
        "read-cmd-shim": "5.0.0"
      }
    },
    "node_modules/read-cmd-shim": {
      "version": "5.0.0",
      "resolved": "https://registry.npmjs.org/read-cmd-shim/-/read-cmd-shim-5.0.0.tgz",
      "integrity": "sha512-SEbJV7tohp3DAAILbEMPXavBjAnMN0tVnh4+9G8ihV4Pq3HYF9h8QNez9zkJ1ILkv9G2BjdzwctznGZXgu/HGw==",
      "license": "ISC",
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    }
  }
}

{
  "name": "verify-read-cmd-shim",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "dependencies": {
    "read-cmd-shim": "5.0.0"
  },
  "scripts": {
    "test": "node test/contract.mjs"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/read-cmd-shim@5.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/read-cmd-shim@5.0.0"
  ]
}

import assert from 'node:assert/strict'
import fs from 'node:fs'
import os from 'node:os'
import path from 'node:path'
import readCmdShim from 'read-cmd-shim'

const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'read-cmd-shim-test-'))

try {
  // 1. Windows .cmd shim
  const cmdShimPath = path.join(tmpDir, 'cli.cmd')
  fs.writeFileSync(
    cmdShimPath,
    '@ECHO off\r\n"node"  "%~dp0\\..\\my-pkg\\bin\\cli.js" %*\r\n',
    'utf8'
  )

  const asyncCmdTarget = await readCmdShim(cmdShimPath)
  assert.equal(asyncCmdTarget, '..\\my-pkg\\bin\\cli.js')

  const syncCmdTarget = readCmdShim.sync(cmdShimPath)
  assert.equal(syncCmdTarget, '..\\my-pkg\\bin\\cli.js')

  // 2. PowerShell .ps1 shim
  const ps1ShimPath = path.join(tmpDir, 'cli.ps1')
  fs.writeFileSync(
    ps1ShimPath,
    '#!/usr/bin/env pwsh\n& "node$exe"  "$basedir/../my-pkg/bin/cli.js" $args\n',
    'utf8'
  )

  const asyncPs1Target = await readCmdShim(ps1ShimPath)
  assert.equal(asyncPs1Target, '../my-pkg/bin/cli.js')

  const syncPs1Target = readCmdShim.sync(ps1ShimPath)
  assert.equal(syncPs1Target, '../my-pkg/bin/cli.js')

  // 3. Cygwin / POSIX shell shim (no extension)
  const shShimPath = path.join(tmpDir, 'cli')
  fs.writeFileSync(
    shShimPath,
    '#!/bin/sh\nexec node  "$basedir/../my-pkg/bin/cli.js" "$@"\n',
    'utf8'
  )

  const asyncShTarget = await readCmdShim(shShimPath)
  assert.equal(asyncShTarget, '../my-pkg/bin/cli.js')

  const syncShTarget = readCmdShim.sync(shShimPath)
  assert.equal(syncShTarget, '../my-pkg/bin/cli.js')

  // 4. Non-shim file throws/rejects with code ENOTASHIM
  const invalidPath = path.join(tmpDir, 'not-a-shim.cmd')
  fs.writeFileSync(invalidPath, 'echo hello\n', 'utf8')

  await assert.rejects(
    () => readCmdShim(invalidPath),
    err => err.code === 'ENOTASHIM'
  )

  assert.throws(
    () => readCmdShim.sync(invalidPath),
    err => err.code === 'ENOTASHIM'
  )
} finally {
  fs.rmSync(tmpDir, { recursive: true, force: true })
}