Introduction to Check-Env

Check-Env is a powerful Node.js library designed to automate and streamline the process of validating environment variables. For developers, managing environment configurations effectively is essential for building secure and scalable applications. With Check-Env, it becomes simpler to handle these configurations, ensuring that variables are set correctly and reducing runtime errors.

Common Check-Env APIs with Examples

init()

Initializes the checks that will be performed. This method must be called before other API methods.

  
    const checkEnv = require('check-env');
    checkEnv.init();
  

check()

Verifies that the specified environment variable is set and optionally validates its value.

  
    checkEnv.check('DB_HOST'); // Ensures DB_HOST is set
    checkEnv.check('NODE_ENV', ['development', 'production']); // Ensures NODE_ENV is either 'development' or 'production'
  

checkAll()

Verifies that all specified environment variables are set and optionally validates their values.

  
    checkEnv.checkAll({
      'DB_HOST': undefined,
      'PORT': undefined,
      'NODE_ENV': ['development', 'production']
    });
  

hasErrors()

Returns a boolean indicating whether there are any errors in the configured checks.

  
    if (checkEnv.hasErrors()) {
      console.error("Environment configuration errors detected!");
    }
  

getErrors()

Returns an array of error messages indicating what checks failed.

  
    const errors = checkEnv.getErrors();
    if (errors.length) {
      errors.forEach(error => console.error(error));
    }
  

Example: Setting Up an Application with Check-Env

Below is a simple example of how to set up a Node.js application to use Check-Env to manage its environment variables:

  
    // app.js
    const express = require('express');
    const checkEnv = require('check-env');

    // Initialize Check-Env
    checkEnv.init();

    // Define required and optional environment variables
    checkEnv.checkAll({
      'DB_HOST': undefined,
      'DB_USER': undefined,
      'DB_PASS': undefined,
      'PORT': '3000',
      'NODE_ENV': ['development', 'production']
    });

    // Check for environment configuration errors
    if (checkEnv.hasErrors()) {
      console.error('Environment configuration errors:');
      checkEnv.getErrors().forEach(error => console.error(error));
      process.exit(1);
    }

    // If no errors, proceed to set up the app
    const app = express();
    const port = process.env.PORT || 3000;

    app.get('/', (req, res) => {
      res.send('Hello World!');
    });

    app.listen(port, () => {
      console.log(`App running on port ${port}`);
    });
  

This setup ensures that your application checks for the necessary environment variables before starting, preventing potential runtime errors due to missing or misconfigured variables.

Start using Check-Env today to maintain error-free environment configurations and build robust applications.

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