Add option for parser to keep comments

parser_rules/advanced_unwrap.js

@@ -148,6 +148,8 @@ var wysihtml5ParserRules = {
             }
         }
     },
+
+    "comments": 1, // if set allows comments to pass
 
     /**
      * Tag list

src/dom/parse.js

@@ -61,7 +61,8 @@ wysihtml5.dom.parse = (function() {
    */
   var NODE_TYPE_MAPPING = {
         "1": _handleElement,
-        "3": _handleText
+        "3": _handleText,
+        "8": _handleComment
       },
       // Rename unknown tags to this
       DEFAULT_NODE_NAME   = "span",
@@ -593,6 +594,11 @@ wysihtml5.dom.parse = (function() {
     }
   }
 
+  function _handleComment(oldNode) {
+    if (currentRules.comments) {
+      return oldNode.ownerDocument.createComment(oldNode.nodeValue);
+    }
+  }
 
   // ------------ attribute checks ------------ \\
   var attributeCheckMethods = {

test/dom/parse_test.js

@@ -797,4 +797,12 @@ if (wysihtml5.browser.supported()) {
     this.equal(this.sanitize(tester, rules).innerHTML, input5 , "DIV with dimensions and in dom is kept");
 
   });
+
+  test("Test keeping comments ", function() {
+    var rules = {
+      "comments": 1
+    },
+    input = 'Test <!-- some comment -->';
+    this.equal(this.sanitize(input, rules), input, "Comments are kept if configured to keep");
+  });
 }