Installation

npm install @remscodes/env-mode

Note

This library does not load environment variables from a .env files.

It is supposed to be used in addition to any module or framework that load these variables.

Usage

// .env
NODE_ENV=dev

Current value

Get the env mode value.

import EnvMode from '@remscodes/env-mode';

EnvMode.get(); // "dev"
EnvMode.getOrThrow(); // "dev"

Conditions

Build conditions based on the env mode.

import EnvMode from '@remscodes/env-mode';

EnvMode.is('dev'); // true
EnvMode.isNot('dev'); // false

EnvMode.in(['dev', 'prod']); // true
EnvMode.notIn(['dev', 'prod']); // false

Selection

Select a specific value depending on the env mode.

import EnvMode from '@remscodes/env-mode';

const color = EnvMode.select({ // "blue"
  dev: 'blue',
  default: 'red',
});

Typed usage

Create a declaration file and add all your env mode values as follows.

// global.d.ts 
declare global {
  namespace NSEnvMode {
    interface ModeMap {
      dev,
      prod,
    }
  }
}

export {};

Include it into your tsconfig.json.

// tsconfig.json
{
  // ...
  "include": [
    "global.d.ts"
  ]
}

Now your env modes can be autocompleted through methods.

Configuration

Throw

By default, if the env mode is empty (undefined or ""), the methods work with this empty value.

You can choose to throw an exception from every methods if env mode is empty.

Example :

// .env
NODE_ENV=

EnvMode.is('dev'); // false

EnvMode.configure({ throwIfEmpty: true });
EnvMode.is('dev'); // [EnvModeException: "NODE_ENV" is not defined in "globalThis.process.env".]

Key

By default, it works with the NODE_ENV key.

You can change it as follows.

Example :

// .env
DENO_ENV=dev

EnvMode.configure({ key: 'DENO_ENV' });
EnvMode.get(); // "dev"

Source

By default, it works with the globalThis.process.env source.

You can change it as follows.

Example :

// environment.ts
export const myEnvironment = {
  NODE_ENV: 'dev',
};

import { myEnvironment } from './environement.ts';

EnvMode.configure({ source: myEnvironment });
EnvMode.get(); // "dev"

License

MIT © Rémy Abitbol.