Core: Compare documents created by parsed HTML

Author: dmethvin

src/core.js

@@ -10,6 +10,18 @@ var oldInit = jQuery.fn.init,
 	// Make sure we trim BOM and NBSP
 	rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
 
+var makeMarkup = function( html ) {
+	var createDoc = window.document.implementation.createHTMLDocument;
+	if ( !createDoc ) {
+		return;
+	}
+	var doc = window.document.implementation.createHTMLDocument( "", "", null );
+	doc.open( "replace" );
+	doc.write( html );
+	doc.close();
+	return doc.body && doc.body.innerHTML;
+};
+
 jQuery.fn.init = function( arg1 ) {
 	var args = Array.prototype.slice.call( arguments ),
 		changed;
@@ -23,12 +35,12 @@ jQuery.fn.init = function( arg1 ) {
 
 	if ( typeof arg1 === "string" && arg1.trim().charAt( 0 ) === "<" ) {
 		if ( !rsingleTag.test( arg1 ) ) {
-		changed = arg1.replace( rxhtmlTag, "<$1></$2>" );
-		if ( changed !== arg1 ) {
-			migrateWarn( "HTML tags must be properly nested and closed: " + arg1 );
+			changed = arg1.replace( rxhtmlTag, "<$1></$2>" );
+			if ( changed !== arg1 && makeMarkup( arg1 ) !== makeMarkup( changed ) ) {
+				migrateWarn( "HTML tags must be properly nested and closed: " + arg1 );
+			}
 		}
 	}
-	}
 
 	return oldInit.apply( this, args );
 };

test/core.js

@@ -74,7 +74,7 @@ QUnit.test( "Improperly closed elements", function( assert ) {
 		jQuery( "<div data-borked='y'><span/> <p/></div>" );
 	} );
 
-	expectWarning( assert, "Elements not self-closable", 3, function() {
+	expectNoWarning( assert, "Elements not self-closable but tolerable", function() {
 		jQuery( "<div class=wonky />" );
 		jQuery( "<p style='width: 2%' />" );
 		jQuery( "<span aria-label='hello' />" );