Hi, I've been evaluating Mergely for use in a custom CMS. It looks very impressive and seems much nicer than any other diff tools that I've tried!
However, I'm seeing some unexpected results with the comparison algorithm. I boiled it down to a fairly simple test case which can be seen here: http://www.mergely.com/PiK2NNBq/
. Here are some of the oddities:
Issue 1: In line 1, why is the word "paragraph" marked in red on the left and blue on the right? It did not change, only the word "here" was added.
Issue 2: In line 3, there were initially two sentences and a third was inserted in between. If you remove lines 4 and 5, the comparison for line 3 is correct. However, once a blank line is added (line 4), the comparison for line 3 changes: the entire paragraph is marked in red on the left and blue on the right! Another oddity: If I remove the word "here" on line 1 on the right side, line 3 comparison results change back to what I expect! Very strange...
Note that the "ignore white space" option does not seem to affect the results. I tried the same example using jsdiff (http://incaseofstairs.com/jsdiff/
) and it produces the correct results... yet it is nowhere near as pretty as Mergely! Any thoughts on these issues? They seem to happen quite often when comparing large blocks of text with multiple paragraphs. Thank you!