title: How can i get data from FormData in javascript?
body: <p>I need to read data from FormData? I try to read something like <code>someFormatData["valueName"]</code> but it not working.
  <code>options["fileId"]</code> or <code>options["file"]</code> does not work. Also I try <code>options.fileId</code> same result:</p>
  
  <pre><code>function upload(file, fileId, callback) {
      var formData = new FormData();
      formData.append("file", file);
      formData.append("fileID", fileId);
  
      $.ajax({
          url: '/url',
          type: 'POST',
          data: formData,
          processData: false,
          contentType: false,
          success: function(response) {
              callback(response);
          }
      });
  }
  
  
  asyncTest("test upload chunk", function() {
      var blob = new Blob(["Hello world!"], { type: "text/plain" }),        
          options = null,
          fileID ="someFileID",
          response;
  
      jQuery.ajax = function(param) {
          options = param;   // THIS is FormData object 
          // how to read fileId and file from here
      };
  
      upload(blob, fileID, function (data) {
          response = data;  
      });
  
      options.success({
          someProp: 'responseFromServer'
      });
  
      setTimeout(function() {
          QUnit.equal(options, "dataTosend", "parameters is OK");
          QUnit.equal(response["someProp"], "responseFromServer", "Response ok");
          start();
      },1000);
  });
  </code></pre>