completly bugfix grid area parsing

Author: jogibear9988

src/AngleSharp.Css.Tests/Declarations/CssGridProperty.cs

@@ -528,13 +528,91 @@ public void CssGridAreaSingleValueLegal()
         }
 
         [Test]
-        public void CssGridAreaSingleTextValueLegal()
+        public void CssGridAreaSingleTextValueLegal1()
         {
-            var source = "#nav-header {grid-area: navheader; }";
+            var source = "#nav-header {grid-area: aaa; }";
             var css = ParseStyleSheet(source);
             var text = css.Rules[0].CssText;
 
-            var expected = "#nav-header { grid-area: navheader / navheader / navheader / navheader }";
+            var expected = "#nav-header { grid-area: aaa / aaa / aaa / aaa }";
+            Assert.AreEqual(expected, text);
+        }
+
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal2()
+        {
+            var source = "#nav-header {grid-area: aaa / bbb; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: aaa / bbb / aaa / bbb }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal3()
+        {
+            var source = "#nav-header {grid-area: 1 / 2; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: 1 / 2 / auto / auto }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal4()
+        {
+            var source = "#nav-header {grid-area: aaa / 2; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: aaa / 2 / aaa / auto }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal5()
+        {
+            var source = "#nav-header {grid-area: aaa / bbb / ccc; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: aaa / bbb / ccc / bbb }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal6()
+        {
+            var source = "#nav-header {grid-area: aaa / bbb / ccc; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: aaa / bbb / ccc / bbb }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal7()
+        {
+            var source = "#nav-header {grid-area: 1; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: 1 / auto / auto / auto }";
+            Assert.AreEqual(expected, text);
+        }
+
+        [Test]
+        public void CssGridAreaSingleTextValueLegal8()
+        {
+            var source = "#nav-header {grid-area: 2 / aaa; }";
+            var css = ParseStyleSheet(source);
+            var text = css.Rules[0].CssText;
+
+            var expected = "#nav-header { grid-area: 2 / aaa / auto / aaa }";
             Assert.AreEqual(expected, text);
         }
 

src/AngleSharp.Css/Declarations/GridAreaDeclaration.cs

@@ -59,24 +59,33 @@ private static ICssValue GetItem(CssTupleValue tuple, Int32 index)
                     return tuple.Items[index];
                 }
 
-                return GetItemSimple(tuple, index / 2);
+                return GetItemSimple(tuple, index);
             }
 
             private static ICssValue GetItemSimple(CssTupleValue tuple, Int32 index)
             {
-                if (tuple.Items.Length > index)
+                if (index <= 2)
                 {
-                    var nested = tuple.Items[index] as CssTupleValue;
-
-                    if (nested != null && nested.Items.Length == 3 && nested.Items[0] == null && nested.Items[1] == null)
-                    {
-                        return nested.Items[2];
+                    if (tuple.Items.Length <= index)
+                    {if (!int.TryParse(tuple.Items[0].CssText, out int _))
+                        {
+                            return tuple.Items[0];
+                        }
                     }
                 }
-
-                if (tuple.Items.Length > 0 && !int.TryParse(tuple.Items[0].CssText, out int _))
+                else if (index == 3)
                 {
-                    return tuple.Items[0];
+                    if (tuple.Items.Length > 1)
+                    {
+                        if (!int.TryParse(tuple.Items[1].CssText, out int _))
+                        {
+                            return tuple.Items[1];
+                        }
+                    }
+                    else if (!int.TryParse(tuple.Items[0].CssText, out int _))
+                    {
+                        return tuple.Items[0];
+                    }
                 }
 
                 return new Constant<Object>(CssKeywords.Auto, null);