I’ve just been learning how incredibly powerful Test First Development is in Rails – being able to test for elements on the dom using assert_select is fantastico!

However I note that there’s no opposite – a deny_select if you will. Something that will test to see if a given element does NOT exist.

Here’s one I cooked up earlier:

def deny_select(element, message)  
  assert_select element, false, message

Use it by passing in the css element id and the message if the assertion fails like this:

deny_select 'table.calendar', "Calendar should not be on page"  
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