title: Typescript - How to declare global variables on node.js
body: <p>How to declare some custom variables globally?</p>
  
  <h3>Usage Example</h3>
  
  <pre><code>import './logger'; // custom module: Global logger is initialized. (using winston)
  
  log.info('This is custom global logger.'); // access to log variable globally.
  </code></pre>