Add diff2html typings and tests (#10681)

diff2html/diff2html-tests.ts

@@ -0,0 +1,26 @@
+/// <reference path="./diff2html.d.ts" />
+
+import Diff2Html = require('diff2html');
+
+let d2h = Diff2Html.Diff2Html;
+
+class Diff2HtmlOptionsImpl implements Diff2Html.Options {  
+    constructor (public inputFormat: string) {
+    }
+} 
+
+let strInput = 
+        'diff --git a/sample b/sample\n' +
+        'index 0000001..0ddf2ba\n' +
+        '--- a/sample\n' +
+        '+++ b/sample\n' +
+        '@@ -1 +1 @@\n' +
+        '-test\n' +
+        '+test1r\n';
+
+let strConfiguration = new Diff2HtmlOptionsImpl('diff');
+let diffInput = d2h.getJsonFromDiff(strInput, strConfiguration);
+
+let diffConfiguration = new Diff2HtmlOptionsImpl('json');
+let htmlString = d2h.getPrettyHtml(diffInput, diffConfiguration);
+console.log(htmlString);