title: How to Print Function Signature in javascript
body: <p>I have a function:</p>
  
  <pre><code>fs.readFile = function(filename, callback) {
      // implementation code.
  };
  </code></pre>
  
  <p>Sometime later I want to see the signature of the function during debugging.</p>
  
  <p>When I tried <code>console.log(fs.readFile)</code> I get <code>[ FUNCTION ]</code>.</p>
  
  <p>That does not give me any information.</p>
  
  <p>How can I get the signature of the function?</p>