ENV validation library

This library is designed to support validating environment variables for a nodejs application of any kind.

How to use

In a file (e.g. config.js)

require('dotenv').config();

const {validate, validations, preProcessors} = require('@learningalbum/env-validation');

const {castBool} = preProcessors;
const {mustBeOneOf, requiredIfPresent, requiredIfTrue} = validations;

const varsConfig = [
  // Array of variable configs (see below)
  {
    name: 'MY_VAR',
    require: true,
  }
]

// Get the validated vars into an object like {VAR1, VAR2, VAR3, etc} 
module.exports = validate(varsConfig);

Then in your application code, wherever you need config from your env, you do stuff like:

const { MY_VAR } = require('config.js');
// Do something with MY_VAR

or, if using ESM:

import envs from './config.js';
const { MY_VAR } = envs;

If MY_VAR doesn't validate in the way you've configured in config.js, an error will be thrown with an error message describing why.

Variable configs

Declare each variable you want to validate. For full details on the interface, please see src/types.ts.

| key | type |required?| description | |-------------|--------------------------------------------------------|-|----------------------------------------------------------------------------------------------------------| | name | string |yes| the name of the variable to pick up from process.env | | default | any |no| a default value to use | | preProcess | (val: any) => any |no| function to transform the value before any validation | | validations | array of (val: any, context?: EnvContext) => boolean |no| function to validate the value | | deprecated | boolean |no| whether this var is marked as deprecated | | message | string |no| the deprecation message to show if the deprecated var is present (only relevant when deprecated: true) |