PuntoEnv

PuntoEnv is a simple package that enables you to load .env files in to process.env and also do variable expansion in a predetermined order based on the NODE_ENV environment variable value.

• Motivation
• Installation
• Getting Started
  • Custom ENV variable
  • Loaded file callback
• How it works.
  • Variable expansion
• License

Motivation

I like how Next.js loads .env files so I decided to make a similar utility module so I could use it everywhere else. Under the hood, it uses dotenv and dotenv-expand packages.

Installation

npm i puntoenv

Getting Started

Setup is really simple, just pass in a path to the directory that has your .env files and that's it!

import { setupEnv } from 'puntoenv'

setupEnv('/path/to/your-dir/')

Custom ENV variable

Also note that NODE_ENV will be the default environment variable that will be checked, but you can use any other variable.

//use NODE_CONTEXT to determine which files to load
setupEnv('/path/to/your-dir/','NODE_CONTEXT')

Make sure you call the function as early as possible in your code.

Loaded file callback

You can pass in optional onLoad callback (to the options object), that will fire for every loaded file. Inside the callback there is info about the path, filename and the result of the dotEnv.config method call.

setupEnv(__dirname, {
  onLoad: (data) => {
    console.log('path ',data.path)
    console.log('filename ',data.filename)
    console.log('result ',data.result) // {error?: Error , parsed:Record<string,string>}
  },
})

How it works.

PuntoEnv will load .env files in a particular order. Environment variables are looked up in the following places, in order, stopping once the variable is found. Environment variables that already exist have the highest priority and will not be overwritten by .env files.

const value = process.env.NODE_ENV // production

- process.env
- .env.$(value).local // .env.production.local
- .env.local
- .env.$(value) // .env.production
- .env

One exception to this rule is when the NODE_ENV=test in that case *.local files will not be loaded as you expect tests to produce the same results for everyone (but you can use .env.test file).

I would also recommend adding all .env*.local files to the .gitignore file.

Variable expansion

After all the files have been processed, the variable expansion will take place. Before expansion:

SERVER=www.example.com:$PORT
PORT=3000

After expansion:

SERVER=www.example.com:3000
PORT=3000

License

This project is licensed under the MIT License - see the LICENSE file for details