Requires jszip and FileSaver and an API key

Google Drive Folder to Direct Zip DL.js

var files = [];
var counter = 0;

async function getFileFromUrl(url, filename, callback){
  const response = await fetch(url);
  const data = await response.blob();
	blobToBase64(data, function (dataURL) { callback(dataURL, url, filename); })
	console.log(data);
  
}

function createArchive(files){
  // Use jszip
  var zip = new JSZip();
  getJSON('https://www.googleapis.com/drive/v2/files/' + folderID + '?key=' + apiKey, function(err, data) {
	  if (err !== null) {
		alert('Something went wrong: ' + err);
	  } else {
		var title = zip.folder(data.title);
		  for (var i=0; i<files.length; i++) {
			var commaIdx = files[i].data.indexOf(",");
			title.file(files[i].filename, files[i].data.slice(commaIdx + 1), {base64: true});
		  }
		  zip.generateAsync({type:"blob"}).then(function(file){
			saveAs(file, data.title + ".zip");
		  })
	  }
  });
}

var blobToBase64 = function(blob, callback) {
    var reader = new FileReader();
    reader.onload = function() {
        var dataUrl = reader.result;
        var base64 = dataUrl.split(',')[1];
        callback(base64);
    };
    reader.readAsDataURL(blob);
};

var getJSON = function(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
    xhr.responseType = 'json';
    xhr.onload = function() {
      var status = xhr.status;
      if (status === 200) {
        callback(null, xhr.response);
      } else if (status === 403){
        console.log(xhr.response.error);
      }else {
        callback(status, xhr.response);
      }
    };
    xhr.send();
};

var folderID = '1D_wU1rI0cySkk5B_Au-frRdmSi901itK';
var apiKey = 'foo';

getJSON('https://www.googleapis.com/drive/v2/files?q=%27' + folderID + '%27+in+parents&key=' + apiKey, function(err, data) {
  if (err !== null) {
    alert('Something went wrong: ' + err);
  } else {
	for (var i = 0; i < data.items.length; i++) {
		console.log(data.items[i].webContentLink)
		getFileFromUrl("https://cors-anywhere.herokuapp.com/" + data.items[i].downloadUrl, data.items[i].title, function (base64Img, url, filename) {
		files.push({
		  url: url,
		  data: base64Img,
		  filename: filename,
		});
		counter++;
		console.log("counter" + counter);
		console.log(files);
		console.log(data.items.length);
		if (counter >= (data.items.length)) {
		  createArchive(files);
		}
	  });
	}
  }
});