How to render text based on differences for human reading in javascript

Question

How to render text based on differences for human reading in javascript

I need to print the embedded text (code) differences in a format for human reading (for example: not optimized by the machine).

My platform is Javascript (main node.js, browser). I have my own printer / stylist, but I'm having trouble making the right diff changes.

It is important that human intuitive changes: such a strong bias towards changes in the line and very little on random fragmented letters.

Examples of non-JS renderers that look good are one of Tortoise SVN / GIT and diff renderer on github.com. I believe github reads the “standard” patch format, but I'm sure there is one more logic to turn this into a rather complicated diff.

Some modules I tried:

diff( https://npmjs.org/package/diff ), but it has an unnatural combination of linear and verbal or characteristic differences. (this is used in mocha, but it is mistaken)
chardiff( https://npmjs.org/package/chardiff ), which is based on diff, but has a semantic filter designed for human readability: it looks better, but still gives fragmented one-letter changes (where the classic diff wont).
diff-match-patch( http://code.google.com/p/google-diff-match-patch ), which is promising, but still not quite 100% (still some conflicting differences).