4

Doing a diff of two different html documents turns out to be an entirely different problem than simply doing a diff of plain text. For example, if I do a naive LCS diff between:

Google</p>

and

Google</a></p>

the diff result is NOT:

</a>

but 

/a></

I've tried most gems out there that claim to be html diff but all of them seem to be just implementing text based LCS diff. Is there any gem that does a diff while taking html tags into account?

Vlad
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  • I don't know of any, but that doesn't mean that they don't exist. It would be interesting to create such a gem, using Nokogiri to generate comparable element trees and do a tree-based diff. Try searching the official gem repo at http://rubygems.org – Phrogz Feb 01 '12 at 17:44
  • possible duplicate of [Diff two XML doc in Ruby?](http://stackoverflow.com/questions/1558613/diff-two-xml-doc-in-ruby) – Phrogz Feb 01 '12 at 17:52

2 Answers2

0

Try Samy diffy or rubygems html-diff

salman
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-2

After much searching for a gem to do this for me, I discovered that I can simply do a string compare between two parsed Nokogiri documents:

def should_match_html(html_text1, html_text2)
  dom1 = Nokogiri::HTML(html_text1)
  dom2 = Nokogiri::HTML(html_text2)
  dom1.to_s.should == dom2.to_s
end

Then you can simply add this in your spec:

should_match_html expected_html, actual_html

The best part is that the built-in rspec matcher will automatically provide you a line-by-line diff result of the mismatched lines.

timherby
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