How to circumvent Firefox's "Document expired" page in Selenium tests

When navigating back to a page that was received from a POST request, undesired side effects may happen. Therefore, modern browsers try to keep users from doing so, i.e. Firefox 24 displays an error page explaining what's wrong. If the user presses "Try Again", it shows an additional alert asking whether the user is certain.

Solution

If you need to circumvent this protection, e.g. to test that your application behaves correctly despite being misused, do this:

Copypage.execute_script 'history.back()'
page.execute_script 'retryThis(this)' # overcome firefox "Document expired" page
step 'I confirm the alert'