envvv

Yet another extendable env parser, comfortably typed.

Install

``sh
npm install envvv
`

Usage

`ts
import {
combine,
str,
int,
float,
bool,
date,
json,
array,
line,
required
} from 'envvv'

type Auth = {
id: string
password: string
}

type User = {
name: string
}

const parse = combine([
str('HOST')('0.0.0.0'),
int('PORT')(8000),
int('N_PROCESS')(),
float('FRACTION')(0.5),
bool('USE_MOCK')(false),
date('START_DATE')(),
required(str('API_KEY')()),
array(str('CORS')('*')),
array(int('SCHEDULED_HOURS')()),
array(int('SCHEDULED_MINUTES')()),
json('AUTH')(),
line(json('USER')()),
])

/*
type parse = (obj: Record) => {
HOST: string
PORT: number
N_PROCESS?: number
FRACTION: number
USE_MOCK: boolean
START_DATE?: Date
API_KEY: string
CORS: string[]
SCHEDULED_HOURS: number[]
SCHEDULED_MINUTES: number[]
AUTH?: Auth
USER: USER[]
}
*/

// const res = parse(process.env)

const processEnv = {
PORT: '8080',
USE_MOCK: 'true',
START_DATE: '2023-01-01T00:00:00.000Z',
API_KEY: 'abcde',
SCHEDULED_MINUTES: '10,20 30\n40,,50 , \n60',
AUTH: '{"id": "abc", "password": "123"}',
USER: '{"name": "Bob"}\n{"name": "Alice"}',
}

const res = parse(processEnv)

/*
res = {
HOST: '0.0.0.0',
PORT: 8080,
N_PROCESS: undefined,
FRACTION: 0.5,
USE_MOCK: true,
START_DATE: Date('2023-01-01T00:00:00.000Z'),
API_KEY: 'abcde',
CORS: ['*'],
SCHEDULED_HOURS: [],
SCHEDULED_MINUTES: [10, 20, 30, 40, 50, 60],
AUTH: {id: 'abc', password: '123'},
USER: [
{name: 'Bob'},
{name: 'Alice'}
]
}
*/
`

Custom resolver

`ts
import { resolve, combine, int } from 'envvv'
import type { Parser } from 'envvv'

const asOnOff: Parser<'ON' | 'OFF'> = (v: string) => {
if (/^on$/i.test(v)) return 'ON'
if (/^off$/i.test(v)) return 'OFF'
throw new Error('failed to parse value as "ON" nor "OFF"')
}

const onoff = resolve(asOnOff)

const parse = combine([
int('PORT')(8080),
onoff('SWITCH')('OFF'),
])

parse({ PORT: 8000 })
/*
{
PORT: 8000,
SWITCH: 'OFF'
}
*/

parse({ SWITCH: 'on' })
/*
{
PORT: 8080,
SWITCH: 'ON'
}
*/

parse({ SWITCH: 'true' })
/*
throws Error('failed to parse value as "ON" nor "OFF"')
*/
``