Improved CSS minification of grid #89

Author: FlorianRappl

CHANGELOG.md

@@ -8,6 +8,7 @@ Released on tbd.
 - Fixed missing semicolon in `@page` rule (#135)
 - Fixed integer serialization of keyframe stops (#128)
 - Fixed ordering of rows and columns in `grid` and `grid-gap` (#137)
+- Added further compactification of CSS tuples (#89, #93)
 
 # 0.17.0
 

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

@@ -534,7 +534,7 @@ public void CssGridAreaTextValueLegal1()
             var css = ParseStyleSheet(source);
             var text = css.Rules[0].CssText;
 
-            var expected = "#nav-header { grid-area: aaa / aaa / aaa / aaa }";
+            var expected = "#nav-header { grid-area: aaa }";
             Assert.AreEqual(expected, text);
         }
 

src/AngleSharp.Css.Tests/Styling/BasicStyling.cs

@@ -210,5 +210,13 @@ public void MinifyWithMultipleDeclarations()
             var result = sheet.ToCss(new MinifyStyleFormatter());
             Assert.AreEqual("h1{top:0;left:2px;border:none}h2{border:1px solid rgba(255, 0, 0, 1)}", result);
         }
+
+        [Test]
+        public void MinifyMinimizesProperties_Issue89()
+        {
+            var sheet = ParseStyleSheet("a { grid-area: aa / aa / aa / aa }");
+            var result = sheet.ToCss(new MinifyStyleFormatter());
+            Assert.AreEqual("a{grid-area:aa}", result);
+        }
     }
 }

src/AngleSharp.Css/Declarations/GridAreaDeclaration.cs

@@ -37,7 +37,16 @@ sealed class GridAreaAggregator : IValueAggregator, IValueConverter
 
             public ICssValue Convert(StringSource source) => converter.Convert(source);
 
-            public ICssValue Merge(ICssValue[] values) => new CssTupleValue(values, seperator);
+            public ICssValue Merge(ICssValue[] values)
+            {
+                // Make single value if all resolve to the same text
+                if (values.Length == 4 && values[0]?.CssText == values[1]?.CssText && values[0]?.CssText == values[2]?.CssText && values[0]?.CssText == values[3]?.CssText)
+                {
+                    return values[0];
+                }
+
+                return new CssTupleValue(values, seperator);
+            }
 
             public ICssValue[] Split(ICssValue value)
             {
@@ -75,12 +84,13 @@ private static ICssValue GetItem(CssTupleValue tuple, Int32 index)
             private static ICssValue GetItemSimple(CssTupleValue tuple, Int32 index)
             {
                 var val = UnitParser.ParseUnit(new StringSource(tuple.Items[0].CssText));
+
                 if (index <= 2)
                 {
                     if (tuple.Items.Length <= index)
                     {
 
-                        if (!int.TryParse(tuple.Items[0].CssText, out int _))
+                        if (!Int32.TryParse(tuple.Items[0].CssText, out var _))
                         {
                             return tuple.Items[0];
                         }
@@ -90,12 +100,12 @@ private static ICssValue GetItemSimple(CssTupleValue tuple, Int32 index)
                 {
                     if (tuple.Items.Length > 1)
                     {
-                        if (!int.TryParse(tuple.Items[1].CssText, out int _))
+                        if (!Int32.TryParse(tuple.Items[1].CssText, out var _))
                         {
                             return tuple.Items[1];
                         }
                     }
-                    else if (!int.TryParse(tuple.Items[0].CssText, out int _))
+                    else if (!Int32.TryParse(tuple.Items[0].CssText, out var _))
                     {
                         return tuple.Items[0];
                     }