transenv

Transform ENV configuration into JavaScript object.

Environment variables are standard way of configuration server apps however they are not much fun to work with. transenv helps you transform your ENV configuration into nice JavaScript object with support for:

• conversion to number or boolean
• default values
• human readable errors on missing envs or envs of wrong format
• ability to use .env file in development mode

Example

Source (index.js)

import transenv from 'transenv'

console.log('---ENV---')
console.log(process.env)
const config = transenv()(function({str, num, bool}) {
  return {
    apiKey: str('API_KEY'), // Required API_KEY env
    host: str('HOST', 'localhost'), // HOST env with default value
    port: num('PORT', 3000), // numeric env PORT
    disableAuthorization: bool('DISABLE_AUTHORIZATION'), // boolean env
  }
})

console.log('\n---CONFIG---')
console.log(config)

Standard output

---ENV---
{ API_KEY: 'very-secret-key',
  PORT: '3124',
  DISABLE_AUTHORIZATION: 'true' }
  
---CONFIG---
{ apiKey: 'very-secret-key',
  host: 'localhost',
  port: 3124,
  disableAuthorization: true }

API

transenv(env?)(fn({str, num, bool}))

The optional argument env can be used in a place of process.env. If the env is not specified and the NODE_ENV is not set to the "production", the .env file is loaded and merged with the actual process.env content. The content of .env is ignored in the production mode (NODE_ENV==="production").

The return value of transenv(env?) is a transformation function providing fn with helpers {str, num, bool}. The result of calling transenv(env)(fn) is the fn({str, num, bool}).

str(key, default)

Returns a value of env[key] or a default if not found. If no default is provided, throws an error.

num(key, default)

The same as str but converts the value to a number.

bool(key)

The same as str but converts the value to a boolean. Default value is always false.