env-armor

Lightweight environment variable validation for Node.js.

Installation

npm install env-armor

Features

• Zero dependencies
• Number validation
• String validation
• Boolean validation
• Enum validation
• Optional environment variables
• Default values
• ESM and CommonJS support

Usage

import { validateEnv } from "env-armor";

const env = validateEnv({
  PORT: {
    type: "number",
    default : 3000
  },
  DEBUG: {
    type: "boolean",
  },
  DATABASE_URL: {
    type: "string",
    optional : true
  },
  NODE_ENV: {
    enum: ["development", "production", "test"],
  },
});

console.log(env.PORT);

Supported Types

Number

PORT: {
  type: "number";
}

String

DATABASE_URL: {
  type: "string";
}

Boolean

DEBUG: {
  type: "boolean";
}

Accepted values:

• true
• false

Enum

NODE_ENV: {
  enum: ["development", "production", "test"];
}

Error Examples

Missing variable

Missing required environment variable: PORT

Invalid number

Invalid environment variable: PORT
Expected type: number
Received: hello

Optional Variables

const env = validateEnv({
  DEBUG: {
    type: "boolean",
    optional: true
  }
});

If DEBUG is missing, validation will be skipped. If DEBUG is present, it will still be validated.

Default Values

const env = validateEnv({
  PORT: {
    type: "number",
    default: 3000
  }
});

If PORT is missing, the default value will be used. Environment variables always take precedence over defaults.

License

MIT