title: tslint Error - Shadowed name: 'err'
body: <p>tslint is currently throwing the following error</p>
  
  <pre><code>Shadowed name: 'err'
  </code></pre>
  
  <p>Here is the code</p>
  
  <pre><code>fs.readdir(fileUrl, (err, files) =&gt; {
          fs.readFile(path.join(fileUrl, files[0]), function (err, data) {
              if (!err) {
                  res.send(data);
              }
          });
      });
  </code></pre>
  
  <p>Anybody have a clue on what the best way would be to solve this and what the error even means?</p>