Joienv

Loads and validate your environement variables using Joi

TL;DR

import JoiEnv from "joienv"
import Joi from "joi"

type Config = {
  misc: {
    baseUrl: string,
    env: string,
    port: number,
  },
  mongo: {
    connectionString: string,
    db?: string
  },
}

const Schema = {
  misc: {
    port: Joi.number().port(), // will read `process.env.port ?? process.env.PORT`
                               // and validate it against this rule
    baseUrl: "BASE_URL", // will validate against `process.env.BASE_URL,
                         // `Joi.string().required().tag("BASE_URL")
    env: /^(dev|staging|prod)$/, // will validate `process.env.env ?? process.env.ENV`
                                 // against this regex
  },
  mongo: {
    cs: Joi.string().required()
           .uri({ scheme: ["mongodb", "mongodb+srv"] }) // validate agains this rule
           .tag("MONGODB_URI"), // check for this env var `process.env.MONGODB_URI`
    db: "?MONGODB_DB" // Will convert in `Joi.string().optional().tag("MONGODB_DB")
  }
}

const config = JoiEnv<Config>(Schema)

NB

• JoiEnv will use the env var as a label, unless specified otherwise
• JoiEnv will first test for the tag OR then the key, then key uppercase and finnaly key lowercase: tag ? process.env[tag] : process.env[key] ?? process.env[key.toUpperCase()] ?? process.env[key.toLowerCase()]
• You can wrap nested objects in Joi.object() for better control

API

loadenv<T>(config: Config): T

Loads & validate your environment, and returns it as the object you want

Config is defined as follow:

type Config = {
  [key: string]:
      string // Takes the environment variable
    | RegExp // Validation object by joi
    | Config // Nested configutaion object
    | Joi.Schema // Joi schema object
}

NB

• when using a string, you can prefix it with a ? to make it optional (e.g. ?FOO)

Q & A

Why is this different than dotenv ?

dotenv is used to inject a "configuration file" into process.env.
Loadenv makes sure your environment is properly configured and is valid.

The two libs can work hand in hands because they do not serve the same purpose.