I am new at selenium testing and am writing a bunch of tests for a webpage that relies heavily on javascript user interaction. 

At first I wrote a lot of assertions of the style 

     If I press button A then
          assert number of visible rows = x,
          assert checkboxes checked are such
          assert title = bar
          .... [20 more]

and so on.



Then I switched to checksumming the HTML using MD5:

     If I press button A then 
         assert md5(html) = 8548bccac94e35d9836f1fec0da8115c.  

And it made my life a whole lot easier...

But is this a bad practice in any way?  

example 

 - I know a HTML file a.htm is working correctly, I copy it as
   a_test.htm as a testcase I make all checksums using selenium in
   `dictionary.txt ('show_all' : ' 8548bccac94e35d9836f1fec0da8115c,
   'hide_all'    :3fdec30c2731d22e2516b1cd1261a1e1, 'filter_by_id_click'
   :    3fdec30c2731d22e2516b1cd1261a1e1) and so on..`
 - The use cases are done in selenium `(driver.findbuttonShowAll.click(), assert(md5(html)==dict['show_all])`
 - Further development that doesn't brake expected html output is safe, when assertion fails I diff the htmls...


UPDATE : 
Note that taking this approach can check dynamic behaviour, because of the fact that the md5 strings are build browserspecific from html in memory.