via npm:

$ npm install diff-parser # use -g if you want to use diff2html

$ git diff [file|dir] > filename.diff
$ diff2html path/to/filename.diff > filename.html

var diffParser = require("diff-parser");
var diffFiles = diffParser.parse(diffString);
console.log(diffFiles); // here have all info you need.

• Right now it only support git diff. So the next improvement should be support more type of diffs.
• Let user customize their styles for the diff html page.

MIT