Configrrr v2.0.1

:angry: Angry configuration for your JS (grrr...)

Automatically overrides your config values with environment variables, command line switches, and local storage.

• :timer_clock: Simple setup, minimal configuration
• :hatched_chick: No dependencies, 881 bytes (minified + gzip)

Installation

npm install configrrr

Usage

import { Config } from 'configrrr';

const config = new Config({
	APP_NAME: 'Example',
	ANGRY: false,
	PORT_NUMBER: 3000,
});

// Override with an environment variable
CONFIG_ANGRY=true npm start

// Override with a command switch
npm start --CONFIG_ANGRY true

// Override 'on the fly' within the browser
localStorage.ANGRY = true;

// Override by hard coding
config.ANGRY = true;

console.log(config.ANGRY);
// true

console.log(config.toJSON());
// { APP_NAME: 'Example', ANGRY: true, PORT_NUMBER: 3000 }

console.log(config.hasOwnProperty('DOES_NOT_EXIST'));
// false

console.log(config.keys);
// [ 'APP_NAME', 'ANGRY', 'PORT_NUMBER' ]

Config override priority

// #1. Hard coded
config.ANGRY = '1st priority';

// #2. Local storage
localStorage.ANGRY = '2nd priority';

// #3. Command switch
npm start --CONFIG_ANGRY '3rd priority'

// #4. Environment variable
// Linux, macOS (Bash):
CONFIG_ANGRY='4th priority' npm start
// Windows (cmd.exe):
set CONFIG_ANGRY='4th priority' && npm start
// Fish shell:
env CONFIG_ANGRY='4th priority' npm start

// #5. Initial config
new Config({ ANGRY: '5th priority' })

CONFIG_ prefix

Notice the environment variables and command switches are prefixed with CONFIG_. This is to avoid accidentally exposing sensitive information to the client.

Usage without ES6 module support

// CommonJS / Node.js
const configrrr = require('configrrr');
const config = new configrrr.Config({ TEST: true });

// AMD / RequireJS 
define(['configrrr'], function(configrrr) {
	const config = new configrrr.Config({ TEST: true });
});

// Global / window
const config = new configrrr.Config({ TEST: true });

Use Case: Layered environment config files

Provide the following directory structure:

• /app/config/index.js
• /app/config/config.default.js
• /app/config/config.env-dev.js
• /app/config/config.env-prod.js
• /app-config.local.js (Ignored from source control)

// /app/config/config.default.js
module.exports = { API_URL: undefined };

// /app/config/config.env-dev.js
module.exports = { API_URL: 'http://dev.example.com/' };

// /app/config/config.env-prod.js
module.exports = { API_URL: 'http://api.example.com/' };

// /app-config.local.js
module.exports = { API_URL: 'http://localhost:1234/' };

// /app/config/index.js

import { Config } from 'configrrr';

const env = process.env.hasOwnProperty('NODE_ENV') ? process.env['NODE_ENV'] : 'dev';

const initConfig = Object.assign(
	{},
	require('./config.default.js'),
	require(`./config.env-${env}.js`),
	require('../../app-config.local.js'),
);

export const config = new Config(initConfig);

// app.js

import { config } from '/app/config/';

console.log(config.API_URL);

Notes

• Config supports key value pairs only
  • Improves performance (no deep merging required)
  • Promotes keeping config files simple

More documentation

• Change log
• Develop
• Release

Roadmap

• Unit tests
• Improve boolean switches (--example instead of --example true)
• TypeScript definition file
• Support for dotenv

Author

Matt Turnbull <[email protected]>

License

Open sourced under the MIT license.