dropzone capybara上传图片黄瓜javascript

Question

我试图模拟dropzone图片上传。我试图遵循这篇StackOverflow文章，但仍然无法正常工作。

How do you test uploading a file with capybara and Dropzone?

def drop_in_dropzone(file_path)
  # Generate a fake input selector
  page.execute_script <<-JS
    fakeFileInput = window.$('<input/>').attr(
      {id: 'fakeFileInput', type:'file'}
    ).appendTo('.dropzone-upload-button');
  JS
  # Attach the file to the fake input selector with Capybara
  attach_file("fakeFileInput", file_path)
  # Trigger the fake drop event
  page.execute_script <<-JS
    var fileList = [fakeFileInput.get(0).files[0]];
    var e = jQuery.Event('drop', { dataTransfer : { files : fileList } });
    $('.dropzone')[0].dropzone.listeners[0].events.drop(e);
  JS
end

错误

$(...)[0].dropzone is undefined (Selenium::WebDriver::Error::JavascriptError)