validate-dotenv

A TypeScript library that simplifies the management of environment variables in Node.js applications. This package provides a robust way to load and validate environment variables from .env files, ensuring required variables are present and correctly typed.

Features

• Load environment variables from a .env file.
• Validate the presence and type of environment variables.
• Support for default values and type checking (string, number, boolean).

Installation

npm install validate-dotenv

Usage

Importing the Library

import { loadEnv, validateEnv } from "validate-dotenv";

Loading Environment Variables

Load the environment variables from a .env file:

loadEnv(".env");

Defining Expected Environment Variables

Define the expected environment variables using the EnvConfig type:

const envConfig = {
  PORT: { required: true, type: "number", defaultValue: "3000" },
  DB_HOST: { required: true, type: "string" },
  USE_CACHE: { required: false, type: "boolean", defaultValue: "false" },
} as const;

Validating Environment Variables

Validate the loaded environment variables:

try {
  validateEnv(envConfig);
  console.log("All environment variables are valid.");
} catch (error) {
  if (error instanceof Error) {
    console.error("Environment variable validation error:", error.message);
  } else {
    console.error("Unexpected error:", error);
  }
}

API

loadEnv(filePath: string): void

Loads environment variables from the specified .env file.

validateEnv(envConfig: EnvConfig): void

Validates the loaded environment variables against the provided configuration.

• Parameters:
  • envConfig: An object that defines the expected environment variables, their required status, type, and default values.

Example

Here’s a complete example that loads and validates environment variables:

import { loadEnv, validateEnv } from "validate-dotenv";

// Load the environment variables from a .env file
loadEnv(".env");

// Define the expected environment variables
const envConfig = {
  PORT: { required: true, type: "number", defaultValue: "3000" },
  DB_HOST: { required: true, type: "string" },
  USE_CACHE: { required: false, type: "boolean", defaultValue: "false" },
} as const;

try {
  validateEnv(envConfig);
  console.log("All environment variables are valid.");
} catch (error) {
  if (error instanceof Error) {
    console.error("Environment variable validation error:", error.message);
  } else {
    console.error("Unexpected error:", error);
  }
}

License

This project is licensed under the ISC License.

Contributing

Feel free to submit issues and pull requests. Contributions are welcome!

Author

Akshat Jain