How to write Unit Test for controller which uses ng-file-upload

I am using jasmine and karma for my front end unit testing of angularjs application.I am couldn't able to figure out how to write test cases that cover progress and success callbacks after calling upload method in ng-file-upload .thanks in adavance

vm.uploadFiles = function(file) {
    Upload.upload({
    url: '/api/documents',
    method: 'POST',
    data: file
    }).progress(function(evt) {
      //Displaying progress of file upload code will come here
    }).success(function(data, status, headers, config) {
      console.log(data);
    });
};