CSS: support for 'of' keyword in :nth-child and :nth-last-child (trul…

…lock#366)

src/NUglify.Tests/Css/Bugs.cs

@@ -163,6 +163,17 @@ public void Bug343()
         }
 
 
+        [Test]
+        public void Bug366()
+        {
+	        Assert.AreEqual("#thisisanid :nth-child(1 of ul.firstclass~ul:not(.secondclass)){background:#f00}", Uglify.Css(@"
+#thisisanid :nth-child(1 of ul.firstclass ~ ul:not(.secondclass)) {
+  background: #ff0000;
+}
+").Code);
+        }
+
+
         [Test]
         public void Bug379()
         {

src/NUglify.Tests/TestData/Core/Expected/ManifestTask/test_bundle.css

@@ -3,6 +3,9 @@
 {
     border-left: 25.0px dashed lightgray;
 }
+.bar:nth-child(n+1 of .test) {
+    background-color: #ff0000;
+}
 /*/#source 1 1 TESTRUNPATH\Out\Dll\Input\ManifestTask\file2.css */
 body
 {

src/NUglify.Tests/TestData/Core/Input/ManifestTask/file1.css

@@ -1,4 +1,7 @@
 .foo:nth-child(n+1) 
 {
     border-left: 25.0px dashed lightgray;
+}
+.bar:nth-child(n+1 of .test) {
+    background-color: #ff0000;
 }

src/NUglify/Css/CssParser.cs

@@ -2564,6 +2564,12 @@ Parsed ParseExpression()
                         }
                         break;
 
+                    case TokenType.Of:
+                        AppendCurrent();
+                        NextToken();
+                        ParseSelector(); // Selectors v4 indicates that :nth-child and :nth-last-child can have their n argument followed by "of S" with S being a selector
+                        break;
+
                     default:
                         // anything else and we bail
                         return parsed;

src/NUglify/Css/CssScanner.cs

@@ -1205,6 +1205,11 @@ CssToken ScanIdent()
                     NextChar();
                     token = ScanProgId();
                 }
+                else if (ident.Equals("of", StringComparison.OrdinalIgnoreCase) && m_currentChar == ' ')
+                {
+                    NextChar();
+                    token = new CssToken(TokenType.Of, " " + ident + " ", m_context);
+                }
                 else
                 {
                     token = new CssToken(TokenType.Identifier, ident, m_context);

src/NUglify/Css/CssToken.cs

@@ -185,6 +185,7 @@ enum TokenType
         Character,
         Comment,
         Fraction,
+        Of,
 
         // CSS3 paged media at-symbols
         TopLeftCornerSymbol,