Extracting zipped files using JSZIP in javascript

Question

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 & 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]'.
Can anyone help me on this? The following is my 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);
      });
    });
  }
});

Answer 1

This is a working version I am using:

var jsZip = require('jszip')
jsZip.loadAsync(file).then(function (zip) {
  Object.keys(zip.files).forEach(function (filename) {
    zip.files[filename].async('string').then(function (fileData) {
      console.log(fileData) // These are your file contents      
    })
  })
})

You can get most of the information you need from http://stuk.github.io/jszip/documentation/examples.html but it's a little hard to get in one place, you have to look around a bit.