dotenv-expand 11.0.7: 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 pkg:npm/dotenv-expand@11.0.7
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/dotenv-expand@11.0.7
Demonstrate these symbols/APIs:
  - expand

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:sha256:4b358013b5445f54487506a38e6b4b634d75de77fda829c5b8bbefeaf3557898","contract":["expand({ parsed: { HOST: 'localhost', PORT: '8080', ADDR: '${HOST}:${PORT}' } }).parsed.ADDR === 'localhost:8080'","expand({ parsed: { DB_HOST: '${UNSET_DB_HOST:-127.0.0.1}' } }).parsed.DB_HOST === '127.0.0.1'","expand({ parsed: { BASE_DIR: '/app', SUB_DIR: '${BASE_DIR}/data', FILE_PATH: '${SUB_DIR}/config.json' } }).parsed.FILE_PATH === '/app/data/config.json'","expand({ parsed: { ESCAPED_DOLLAR: '\\\\$VAR_LITERAL' } }).parsed.ESCAPED_DOLLAR === '$VAR_LITERAL'"],"goal":"verify pkg:npm/dotenv-expand@11.0.7","kind":"HOW","packages":["pkg:npm/dotenv-expand@11.0.7"],"schemaVersion":1,"symbols":["expand"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/dotenv-expand@11.0.7"],"schemaVersion":1,"subject":"pkg:npm/dotenv-expand@11.0.7","symbols":["expand"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-dotenv-expand",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-dotenv-expand",
      "version": "1.0.0",
      "dependencies": {
        "dotenv-expand": "11.0.7"
      }
    },
    "node_modules/dotenv": {
      "version": "16.6.1",
      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.6.1.tgz",
      "integrity": "sha512-uBq4egWHTcTt33a72vpSG0z3HnPuIl6NqYcTrKEg2azoEyl2hpW0zqlxysq2pK9HlDIHyHyakeYaYnSAwd8bow==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=12"
      },
      "funding": {
        "url": "https://dotenvx.com"
      }
    },
    "node_modules/dotenv-expand": {
      "version": "11.0.7",
      "resolved": "https://registry.npmjs.org/dotenv-expand/-/dotenv-expand-11.0.7.tgz",
      "integrity": "sha512-zIHwmZPRshsCdpMDyVsqGmgyP0yT8GAgXUnkdAoJisxvf33k7yO6OuoKmcTGuXPWSsm8Oh88nZicRLA9Y0rUeA==",
      "license": "BSD-2-Clause",
      "dependencies": {
        "dotenv": "^16.4.5"
      },
      "engines": {
        "node": ">=12"
      },
      "funding": {
        "url": "https://dotenvx.com"
      }
    }
  }
}

{
  "name": "sample-dotenv-expand",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "dotenv-expand": "11.0.7"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/dotenv-expand@11.0.7",
  "kind": "HOW",
  "packages": [
    "pkg:npm/dotenv-expand@11.0.7"
  ],
  "symbols": [
    "expand"
  ]
}

import assert from 'node:assert/strict';
import { expand } from 'dotenv-expand';

// 1. Basic variable interpolation
{
  const customEnv = {};
  const config = {
    processEnv: customEnv,
    parsed: {
      HOST: 'localhost',
      PORT: '8080',
      ADDR: '${HOST}:${PORT}'
    }
  };
  const res = expand(config);
  assert.equal(res.parsed.ADDR, 'localhost:8080');
  assert.equal(customEnv.ADDR, 'localhost:8080');
}

// 2. Default value fallback when variable is unset
{
  const customEnv = {};
  const config = {
    processEnv: customEnv,
    parsed: {
      DB_HOST: '${UNSET_DB_HOST:-127.0.0.1}',
      DB_PORT: '${UNSET_DB_PORT:-5432}'
    }
  };
  const res = expand(config);
  assert.equal(res.parsed.DB_HOST, '127.0.0.1');
  assert.equal(res.parsed.DB_PORT, '5432');
}

// 3. Nested variable substitution
{
  const customEnv = {};
  const config = {
    processEnv: customEnv,
    parsed: {
      BASE_DIR: '/app',
      SUB_DIR: '${BASE_DIR}/data',
      FILE_PATH: '${SUB_DIR}/config.json'
    }
  };
  const res = expand(config);
  assert.equal(res.parsed.FILE_PATH, '/app/data/config.json');
}

// 4. Escaped variable sequence preservation
{
  const customEnv = {};
  const config = {
    processEnv: customEnv,
    parsed: {
      ESCAPED_DOLLAR: '\\$VAR_LITERAL'
    }
  };
  const res = expand(config);
  assert.equal(res.parsed.ESCAPED_DOLLAR, '$VAR_LITERAL');
}

console.log('Contract test passed.');