Register preference and interaction media features

src/ExCSS.Tests/PreferenceMediaFeaturesTests.cs

@@ -0,0 +1,63 @@
+namespace ExCSS.Tests
+{
+    using ExCSS;
+    using Xunit;
+
+    // Registration-only coverage for the preference/interaction media features
+    // (Media Queries 5 / 4). Evaluation/matching is out of scope; these tests
+    // assert only that each feature is recognized as a typed media feature and
+    // does not degrade to "not all" (which is what an UnknownMediaFeature does).
+    public class PreferenceMediaFeaturesTests : CssConstructionFunctions
+    {
+        [Theory]
+        [InlineData("prefers-color-scheme", "dark")]
+        [InlineData("prefers-color-scheme", "light")]
+        [InlineData("prefers-reduced-motion", "reduce")]
+        [InlineData("prefers-reduced-motion", "no-preference")]
+        [InlineData("prefers-contrast", "more")]
+        [InlineData("prefers-reduced-transparency", "reduce")]
+        [InlineData("update", "fast")]
+        [InlineData("any-hover", "hover")]
+        [InlineData("any-pointer", "fine")]
+        public void RegisteredPreferenceFeatureParsesAndRoundTrips(string feature, string value)
+        {
+            var source = $"@media ({feature}: {value}) {{ h1 {{ color: green }} }}";
+            var sheet = ParseStyleSheet(source);
+
+            Assert.Equal(1, sheet.Rules.Length);
+            Assert.IsType<MediaRule>(sheet.Rules[0]);
+            var media = (MediaRule)sheet.Rules[0];
+
+            // A registered feature round-trips; an unregistered one degrades to "not all".
+            Assert.NotEqual("not all", media.ConditionText);
+            Assert.Equal($"({feature}: {value})", media.Media.MediaText);
+            Assert.Equal(1, media.Media.Length);
+            Assert.Equal(1, media.Rules.Length);
+        }
+
+        [Fact]
+        public void PreferenceFeatureCombinedWithMediaTypeParses()
+        {
+            var source = "@media screen and (prefers-color-scheme: dark) { h1 { color: green } }";
+            var sheet = ParseStyleSheet(source);
+
+            Assert.Equal(1, sheet.Rules.Length);
+            var media = Assert.IsType<MediaRule>(sheet.Rules[0]);
+            Assert.Equal("screen and (prefers-color-scheme: dark)", media.Media.MediaText);
+            Assert.Equal(1, media.Rules.Length);
+        }
+
+        [Fact]
+        public void UnregisteredFeatureStillDegradesToNotAll()
+        {
+            // Guards the assertion above: a genuinely unknown feature must degrade,
+            // proving the round-trip checks are meaningful.
+            var source = "@media (prefers-nonsense: banana) { h1 { color: green } }";
+            var sheet = ParseStyleSheet(source);
+
+            Assert.Equal(1, sheet.Rules.Length);
+            var media = Assert.IsType<MediaRule>(sheet.Rules[0]);
+            Assert.Equal("not all", media.ConditionText);
+        }
+    }
+}

src/ExCSS/Enumerations/FeatureNames.cs

@@ -44,5 +44,12 @@ public static class FeatureNames
         public static readonly string Hover = "hover";
         public static readonly string BlockSize = "block-size";
         public static readonly string InlineSize = "inline-size";
+        public static readonly string PrefersColorScheme = "prefers-color-scheme";
+        public static readonly string PrefersReducedMotion = "prefers-reduced-motion";
+        public static readonly string PrefersContrast = "prefers-contrast";
+        public static readonly string PrefersReducedTransparency = "prefers-reduced-transparency";
+        public static readonly string Update = "update";
+        public static readonly string AnyHover = "any-hover";
+        public static readonly string AnyPointer = "any-pointer";
     }
 }

src/ExCSS/Factories/MediaFeatureFactory.cs

@@ -63,6 +63,13 @@ internal sealed class MediaFeatureFactory
                 {FeatureNames.Hover, () => new HoverMediaFeature()},
                 {FeatureNames.InlineSize, () => new SizeMediaFeature(FeatureNames.InlineSize)},
                 {FeatureNames.BlockSize, () => new SizeMediaFeature(FeatureNames.BlockSize)},
+                {FeatureNames.PrefersColorScheme, () => new PrefersColorSchemeMediaFeature()},
+                {FeatureNames.PrefersReducedMotion, () => new PrefersReducedMotionMediaFeature()},
+                {FeatureNames.PrefersContrast, () => new PrefersContrastMediaFeature()},
+                {FeatureNames.PrefersReducedTransparency, () => new PrefersReducedTransparencyMediaFeature()},
+                {FeatureNames.Update, () => new UpdateMediaFeature()},
+                {FeatureNames.AnyHover, () => new AnyHoverMediaFeature()},
+                {FeatureNames.AnyPointer, () => new AnyPointerMediaFeature()},
             };
 
         #endregion

src/ExCSS/MediaFeatures/AnyHoverMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class AnyHoverMediaFeature : MediaFeature
+    {
+        public AnyHoverMediaFeature() : base(FeatureNames.AnyHover)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/AnyPointerMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class AnyPointerMediaFeature : MediaFeature
+    {
+        public AnyPointerMediaFeature() : base(FeatureNames.AnyPointer)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/PrefersColorSchemeMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class PrefersColorSchemeMediaFeature : MediaFeature
+    {
+        public PrefersColorSchemeMediaFeature() : base(FeatureNames.PrefersColorScheme)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/PrefersContrastMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class PrefersContrastMediaFeature : MediaFeature
+    {
+        public PrefersContrastMediaFeature() : base(FeatureNames.PrefersContrast)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/PrefersReducedMotionMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class PrefersReducedMotionMediaFeature : MediaFeature
+    {
+        public PrefersReducedMotionMediaFeature() : base(FeatureNames.PrefersReducedMotion)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/PrefersReducedTransparencyMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class PrefersReducedTransparencyMediaFeature : MediaFeature
+    {
+        public PrefersReducedTransparencyMediaFeature() : base(FeatureNames.PrefersReducedTransparency)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}

src/ExCSS/MediaFeatures/UpdateMediaFeature.cs

@@ -0,0 +1,11 @@
+namespace ExCSS
+{
+    internal sealed class UpdateMediaFeature : MediaFeature
+    {
+        public UpdateMediaFeature() : base(FeatureNames.Update)
+        {
+        }
+
+        internal override IValueConverter Converter => Converters.Any;
+    }
+}