validate-env-vars

A lightweight utility to check the presence and validity of environment variables, as specified by a Zod schema

Installation

Using npm:

npm install validate-env-vars --save-dev

Usage Examples

Create an executable JS file to check an .env file against a Zod schema:

#!/usr/bin/env node

import validateEnvVars, {
	envEnum,
	envString,
	envNonEmptyString,
} from 'validate-env-vars';

const envSchema = envObject({
	NODE_ENV: envEnum(['development', 'production', 'test']),
	API_BASE: envString().url(),
	GITHUB_USERNAME: envNonEmptyString(),
});

validateEnvVars({ schema: envSchema });

You may use the predefined env* functions, or create your own using Zod

---

Programmatically check an .env.production file against a Zod schema:

import validateEnvVars, {
    envEnum,
    envString,
    envNonEmptyString,
} from 'validate-env-vars';

const envSchema = envObject({
	NODE_ENV: envEnum(['development', 'production', 'test']),
	API_BASE: envString().url(),
	GITHUB_USERNAME: envNonEmptyString(),
});

const prefilight() => {
    try {
        validateEnvVars({ schema: envSchema, envPath: '.env.production' })
        // ... other code
    }
    catch (error) {
        console.error(error);
        // ... other code
    }
}

---

Check env vars before Vite startup and build:

1. Define a Zod schema in a .ts file at the root of your project

import validateEnvVars, {
    envEnum,
    envString,
    envNonEmptyString,
} from 'validate-env-vars';

const envSchema = envObject({
	NODE_ENV: envEnum(['development', 'production', 'test']),
	VITE_API_BASE: envString().url(),
	VITE_GITHUB_USERNAME: envNonEmptyString(),
});

// make the type of the environment variables available globally
declare global {
    type Env = z.infer<typeof envSchema>;
}

export default envSchema;

2. Import validateEnvVars and your schema and add a plugin to your Vite config to call validateEnvVars on buildStart

import { defineConfig } from 'vitest/config';
import envConfigSchema from './env.config';
import validateEnvVars from 'validate-env-vars';

export default defineConfig({
  plugins: [
    {
      name: 'validate-env-vars',
      buildStart: () => validateEnvVars({ schema: envConfigSchema }),
    },
    // other plugins...
  ],
  // other options...

3. Enable typehints and intellisense for the environment variables in your vite-env.d.ts

/// <reference types="vite/client" />

interface ImportMetaEnv extends globalThis.Env {}

interface ImportMeta {
	readonly env: ImportMetaEnv;
}

4. Add your schema configuration file to your tsconfig's include

Tips:

• If you don't have a .env file, you can pass an empty file. This is useful for testing and CI/CD environments, where environment variables may be set programmatically.

Config Options

Option	Type	Description	Default
schema	EnvObject	The schema to validate against
envPath (optional)	string	The path to the .env file	.env
exitOnError (optional)	boolean	Whether to exit the process or throw if validation fails	false
logVars (optional)	boolean	Whether to output successfully parsed variables to the console	true