title: Extracting zipped files using JSZIP in javascript
body: <p>In my webpage, a user is supposed to upload a zipped file. Within the zipped file are 2 files: another zip file and a txt file. On my server, after receiving the zip, I want to unzip the zip file to extract the zip &amp; txt file, then move those 2 files to a predefined folder. I have a piece of code that extracts the zip file, but the data doesn't seem correct. Firstly, it unzipped a zip and 2 txt file when there should only be 1 txt file. It created an additional 'undefined' txt file. Also, in my txt file, instead of the original data, it was replaced with the following text: '[undefined] [undefined]'. <br>
  Can anyone help me on this? The following is my code:</p>
  
  <pre><code>var JSZip = require('JSZip');
  
  fs.readFile( filePath, function(err, data){
    if (!err){
      var zip = new JSZip();
      JSZip.loadAsync(data).then(function(zip){
        object.keys(zip.files).forEach(function(filename){
          var content = zip.files[filename];
          var dest = path + filename;
          fs.writeFileSync(dest, content);
        });
      });
    }
  });
  </code></pre>