envconfig

Envconfig is a helper zero-dependency module to load environment values with formatter 😉.

const e = envconfig({ env: process.env })

const port: number = e('PORT', 'number') ?? 3000;
const ssl: boolean = e('SSL', 'boolean') ?? false;

Features:

• Support to Deno
• Default load config from process.env
• Formatter value using option [type]: e('ENV', { type: Types }) => Types | undefined or e('ENV', Types) => Types | undefined
  • Formatters supported:
    • string formatter (Default): Ex. e('ENV') => string | undefined
    • number formatter: Ex. e('ENV', { type: 'number' }) => number | undefined
    • bigint formatter: Ex. e('ENV', { type: 'bitint' }) => bitint | undefined
    • boolean formatter: Ex. e('ENV', { type: 'boolean' }) => boolean | undefined
    • Custom formatter: Ex. e('ENV', { type: v => new Date(v) }) => Date | undefined
• Typescript support
  • Samples:
    • e('ENV', 'number') => number | undefined
    • e('ENV', v => new Date(v)) => Date | undefined
• Assert values
  • Samples:
    • e('ENV', { type: 'number', required: true }) => number
    • e('ENV', { type: v => new Date(v), required: true }) => Date

How to use

Install dependency @jondotsoy/envconfig

# With npm
$ npm i @jondotsoy/envconfig

Usage with Deno

Import the module using the next url https://unpkg.com/@jondotsoy/envconfig@latest/index.ts

import envconfig from 'https://unpkg.com/@jondotsoy/envconfig@latest/index.ts';

const e = envconfig({ env: Deno.env.toObject() });

Usage

Require and configure envconfig.

// my_configs.ts
import envconfig from '@jondotsoy/envconfig';

const e = envconfig();

Use your instance e in your code. For example, using PORT env if exists or assign a default value.

const port: number = e('PORT', 'number') ?? 3000;

Options envconfig([{ env?, prefix?, sufix? }]): e(key: string)

env

• Optional
• Type:

declare type env = { [k: string]: string }

• Default: process.env

Specify origins data, the method e() is using this value to read and transform values.

const e = envconfig({ env: { PORT: '6000' } });

const port: number = e('PORT', 'number', true);

prefix

• Optional
• Type:

declare type prefix = string

Used to simplify the reading values that contain prefixes on all values required. Its util to complex strategies.

const e = envconfig({
    env: { AWS_ACCESS_KEY_ID: 'a123', AWS_SECRET_ACCESS_KEY: 'abcdeaw12343****' },
    prefix: 'AWS_',
});

const accessKeyId: string = e('ACCESS_KEY_ID', 'string', true);
const secretAccessKey: string = e('SECRET_ACCESS_KEY', 'string', true);

sufix

• Optional
• Type:

declare type sufix = string

Used to simplify the reading the values that can have a suffix. It has preferer the key with the suffix if not exists the key with the suffix this to find a key without the suffix.

Demo 1

const e = envconfig({
    env: { API_KEY: 'abc123', API_KEY_STAGING: 'def456' },
    sufix: '_STAGING',
});

const apiKey: string = e('API_KEY', 'string', true);

assert(apiKey).to.be.equal('def456');

Demo 2

const e = envconfig({
    env: { API_KEY: 'abc123', API_KEY_PRODUCTION: 'def456' },
    sufix: '_STAGING',
});

const apiKey: string = e('API_KEY', 'string', true);

assert(apiKey).to.be.equal('abc123');

Options e(key: string[, { type?: Types, required?: boolean }])

• Other Syntax: e(key: string[, type: Types[, required: boolean]])

key

• required
• Type:

declare type key = string

It's a string that is a referrer to the key in the object env.

const key = 'PORT'
const env = { PORT: '1234' }

const e = envconfig({ env })

const port = e(key) // '1234'

type

• Optional
• Type:

declare type Types = 'number' | 'boolean' | 'string' | 'bigint' | ((v: string) => any);

This param is optional, a string or a function. This is used to indicate how is interpreted the value found. If the value found is undefined that value will not be interpreted.

If is equal to string, the value found is transformed to String.

const port = e('PORT', 'string')

assert.ok(typeof port === 'string')

If is equal to number, the value found is transformed to Number.

const port = e('PORT', 'number')

assert.ok(typeof port === 'number')

If is equal to boolean, the value found is transformed to Boolean.

const verbose = e('VERBOSE', 'boolean')

assert.ok(typeof verbose === 'boolean')

If is equal to bigint, the value found is transformed to BigInt.

const memmax = e('MEMMAX', 'bigint')

assert.ok(typeof memmax === 'bigint')

If is a function, it is used to transform value, only if is not undefined the value found.

Demo 1

const toDate = (v) => new Date(v)

const openService = e('OPEN_SERVICE', toDate)

assert.ok(openService instanceof Date)

Demo 2

const base64ToBuffer = (v) => Buffer.from(v, 'base64')

const keySecret = e('KEY_SECRET', base64ToBuffer)

assert.ok(keySecret instanceof Buffer)

required

• Optional
• Type:

declare type required = boolean

if is equal to true the value found will have be not undefined else it throw a error.