@homer0/env-utils

🏠 Env utils

A really small service to centralize the place where you read and write environment variables, and check if you are running on development or production.

🍿 Usage

• ⚠️ This package is only for Node.
• If you are wondering why I built this, go to the Motivation section.

• ⚙️ Examples
• 🤘 Development

⚙️ Examples

Let's say your code looks something like this:

if (process.env.NODE_ENV !== 'production') {
  addSomeStuffForDevelopment();
}

console.log(`Hello ${process.env.NAME}`);

Let's implement the same but with EnvUtils:

import { envUtils } from '@homer0/env-utils';

const env = envUtils();

if (env.development) {
  addSomeStuffForDevelopment();
}

// The service allows you to set a default in case the variable is not defined.
const name = env.get('NAME', 'Rosario');
console.log(`Hello ${name}`);

Done! Now you are not manually checking for NODE_ENV and all your variables are being read on a single place.

Writing environment variables

Writing on the environment from inside an application is not that common as reading, but there are certain cases where this may come in handy.

Let's say you are using a library that has a "debug mode" but the only way to enable it is using a environment variable, and for "purposes of debugging", you want to do it from your code:

process.env.DEBUG_MY_LIBRARY = 'true';
runMyMagicLibrary();

Like for get, set also allows you to centralize where you overwrite your environment variables, but at the same time, it protects you from overwriting something that is already declared: Unless you tell set to overwrite declarations, if the variable already exists, it won't do it:

import { envUtils } from '@homer0/env-utils';

const env = envUtils();

// If you add a third parameter with `true`, it will overwrite any previous declaration.
const name = env.set('DEBUG_MY_LIBRARY', 'true');
runMyMagicLibrary();

Done! Now you are not manually updating the environment variable and potentially overwriting something that was already declared.

Jimple provider

If your app uses a Jimple container, you can register EnvUtils as the envUtils service by using its provider:

import { envUtilsProvider } from '@homer0/env-utils';

// ...

container.register(envUtilsProvider);

// ...

const env = container.get('envUtils');

And since the provider is a "provider creator" (created with my custom version of Jimple), you can customize its service name:

container.register(
  envUtilsProvider({
    serviceName: 'myEnvUtils',
  }),
);

🤘 Development

As this project is part of the packages monorepo, some of the tooling, like lint-staged and husky, are installed on the root's package.json.

Tasks

Task	Description
lint	Lints the package.
test	Runs the unit tests.
build	Transpiles and bundles the project.
types:check	Validates the TypeScript types.

Motivation

This used to be part of the wootils package, my personal lib of utilities, but I decided to extract them into individual packages, as part of the packages monorepo, and take the oportunity to migrate them to TypeScript.

Is not uncommon nowadays for Node apps to be checking NODE_ENV and other environment variables in order to do or not to do certain things, and having multiple calls to process.env on different places of your app may not be a good idea: It's hard to track and maintain.