guard-env

Guard-env is a Node.js module for type-checking and guarding environment variables based on specified configurations.

Installation

You can install guard-env via npm:

npm install guard-env

Usage

import { guardEnv } from 'guard-env';
import 'dotenv/config'; // Don't forget to load environment variables

// Example configuration
const config = {
    PORT: Number,
    ENABLED: Boolean,
    API_KEY: String
};

// Guarding environment variables
const env = guardEnv(process.env, config);

// Accessing type-checked environment variables
console.log(env.PORT); // 3000
console.log(env.ENABLED); // true
console.log(env.API_KEY); // 'secret

// Accessing non-existent variable will throw an error
console.log(env.NON_EXISTENT); // Error: 'NON_EXISTENT' is not defined in 'guard-env' config

API

guardEnv

Guards the environment variables based on the provided configuration and returns a proxy object with type-checked values.

• env: The Node.js process environment variables.
• setConfig: The configuration object specifying the expected types for each environment variable.

Returns a proxy object with type-checked values.

Throws an Error if:

• Configuration is empty.

  const env = guardEnv(process.env, {});
  
  console.log(env);
  // Error: Configuration is empty

• A variable is not defined in the environment.

  PORT=3000

  const config = {
      PORT: Number,
      ENABLED: Boolean
  };
  const env = guardEnv(process.env, config);
  
  console.log(env.ENABLED);
  // Error: 'ENABLED' is not defined in 'guard-env' config

• An unsupported type is specified in the configuration. Throws a TypeError if a variable is not of the expected type (number, boolean, or string).

  PORT=THREE_THOUSAND
  ENABLED=ON

  const config = {
      PORT: Number,
      ENABLED: Boolean
  };
  const env = guardEnv(process.env, config);
  
  console.log(env.PORT);
  // TypeError: 'PORT' is not of type number
  console.log(env.ENABLED);
  // TypeError: 'ENABLED' is not of type boolean

• An unsupported type is specified in the configuration.

  const config = {
      DATE: Date
  };
  const env = guardEnv(process.env, config);
  
  console.log(env.DATE);
  // Error: 'Date' type is not supported

Examples

Check out the examples directory for more usage examples.

License

This project is licensed under the MIT License - see the LICENSE file for details.