$ npm i valienv --save
# --- or ---
$ yarn add valienv

typeof env = Readonly<{ // ACCENT_COLOR: string; // TIMEOUT_MS: number; // ENABLE_ANALYTICS: boolean; // }>">

import { bool, nbr, str, validateEnv } from "valienv";

// with process.env = {
//   ACCENT_COLOR: "#0099e5",
//   TIMEOUT_MS: "5000",
//   ENABLE_ANALYTICS: "true",
// }

export const env = validateEnv({
  env: process.env,
  validators: {
    // we validate env using bundled validators
    ACCENT_COLOR: str,
    TIMEOUT_MS: nbr,
    ENABLE_ANALYTICS: bool,
  },
});

// -> typeof env = Readonly<{
//   ACCENT_COLOR: string;
//   TIMEOUT_MS: number;
//   ENABLE_ANALYTICS: boolean;
// }>

typeof env = Readonly<{ CONTACT_EMAIL: string }>">

import { str, validateEnv } from "valienv";

// with process.env = {
//   REACT_APP_CONTACT_EMAIL: "[email protected]",
// }

export const env = validateEnv({
  env: process.env,
  prefix: "REACT_APP_",
  validators: {
    CONTACT_EMAIL: str,
  },
});

// -> typeof env = Readonly<{ CONTACT_EMAIL: string }>

typeof env = Readonly<{ CONTACT_EMAIL: string }>">

import { str, validateEnv } from "valienv";

// with process.env = {
//   CONTACT_EMAIL: "[email protected]",
// }

export const env = validateEnv({
  env: process.env,
  validators: {
    CONTACT_EMAIL: str,
  },
  overrides: {
    ...(process.env.NODE_ENV === "test" && {
      CONTACT_EMAIL: "no-mail",
    }),
  },
});

// -> typeof env = Readonly<{ CONTACT_EMAIL: string }>

= (value /*: string*/) => { const parsed = parseInt(value); if (parsed > 0 && parsed < 65536) { return parsed; } }; // with process.env = { // PORT: "3000", // } export const env = validateEnv({ env: process.env, validators: { PORT: port, }, }); // -> typeof env = Readonly<{ PORT: number }>">

import { validateEnv, Validator } from "valienv";

// A validator take raw input, try to parse it and
// returns the result in case of valid value:
const port: Validator<number> = (value /*: string*/) => {
  const parsed = parseInt(value);

  if (parsed > 0 && parsed < 65536) {
    return parsed;
  }
};

// with process.env = {
//   PORT: "3000",
// }

export const env = validateEnv({
  env: process.env,
  validators: {
    PORT: port,
  },
});

// -> typeof env = Readonly<{ PORT: number }>

{ if (validator.isEthereumAddress(value)) { return value; } }, NODE_ENV: (value) => { if ( value === "development" || value === "test" || value === "production" ) { return value; } }, OPENED_COUNTRIES: (value) => { const array = value.split(","); if (array.every(validator.isISO31661Alpha2)) { return array; } }, }, }); // -> typeof env = Readonly<{ // ETHEREUM_ADDRESS: string; // NODE_ENV: "development" | "production" | "test"; // OPENED_COUNTRIES: string[]; // }>">

import validator from "validator";
import { validateEnv } from "valienv";

// with process.env = {
//   ETHEREUM_ADDRESS: "0xb794f5ea0ba39494ce839613fffba74279579268",
//   NODE_ENV: "development",
//   OPENED_COUNTRIES: "FR,BE,DE",
// }

export const env = validateEnv({
  env: process.env,
  validators: {
    // inlined validators return types are correctly infered
    ETHEREUM_ADDRESS: (value) => {
      if (validator.isEthereumAddress(value)) {
        return value;
      }
    },
    NODE_ENV: (value) => {
      if (
        value === "development" ||
        value === "test" ||
        value === "production"
      ) {
        return value;
      }
    },
    OPENED_COUNTRIES: (value) => {
      const array = value.split(",");

      if (array.every(validator.isISO31661Alpha2)) {
        return array;
      }
    },
  },
});

// -> typeof env = Readonly<{
//   ETHEREUM_ADDRESS: string;
//   NODE_ENV: "development" | "production" | "test";
//   OPENED_COUNTRIES: string[];
// }>