env-doctor

Catch missing or undocumented environment variables before your app crashes.

env-doctor compares your .env file against .env.example and tells you exactly what's missing, empty, or undocumented — so new teammates (and CI) stop failing on undefined is not a function five minutes into setup.

Install

npm install --save-dev env-doctor

Or run it without installing:

npx env-doctor

Usage

env-doctor

Example output:

env-doctor: comparing .env against .env.example

✖ Missing 2 required key(s):
   - API_KEY
   - DEBUG

ℹ 1 key(s) in .env not documented in .env.example:
   - EXTRA_UNDOCUMENTED_KEY

Add it as a pre-dev-server gate in package.json:

{
  "scripts": {
    "predev": "env-doctor",
    "dev": "next dev"
  }
}

Options

| Flag | Description | Default | |---|---|---| | --example <file> | Path to the example env file | .env.example | | --env <file> | Path to the actual env file | .env | | --strict | Also fail if .env has undocumented keys | false | | -h, --help | Show help | |

Exit codes

• 0 — all good
• 1 — missing required keys (or extra keys in --strict mode)
• 2 — couldn't find the example file

License

MIT