title: testing show/hide with minitest capybara rails
body: <p>I'm trying to test the visibility of a div after clicking a button. </p>
  
  <pre><code>   assert page.find("#visu")[:class].include?("hidden") # this passes
     assert page.has_xpath?("//*[@id='visu'][contains(@style, 'display: none')]")
     click_button("Show/hide")
     assert page.has_xpath?("//*[@id='visu'][contains(@style, 'display: block')]")
  </code></pre>
  
  <p>Unfortunately this doesn't work. Any tips?</p>
  
  <p>I am using 'minitest-rails-capybara'</p>