Add tests for font feature enabling and disabling in TextStyle

Source/QuestPDF.UnitTests/TextSpanTests.cs

@@ -4,6 +4,7 @@ using NUnit.Framework;
 using QuestPDF.Elements.Text;
 using QuestPDF.Elements.Text.Items;
 using QuestPDF.Fluent;
+using QuestPDF.Helpers;
 using QuestPDF.Infrastructure;
 
 namespace QuestPDF.UnitTests;
@@ -132,4 +133,43 @@ public class TextSpanTests
     }
     
     #endregion
+    
+    #region Font Features
+    
+    [Test]
+    public void EnableFontFeature_SingleFeature()
+    {
+        var (descriptor, textBlockSpan) = CreateTextBlockSpan();
+        
+        descriptor.EnableFontFeature(FontFeatures.StandardLigatures);
+        Assert.That(textBlockSpan.Style.FontFeatures, Has.Length.EqualTo(1));
+        Assert.That(textBlockSpan.Style.FontFeatures[0], Is.EqualTo((FontFeatures.StandardLigatures, true)));
+    }
+    
+    [Test]
+    public void DisableFontFeature_SingleFeature()
+    {
+        var (descriptor, textBlockSpan) = CreateTextBlockSpan();
+        
+        descriptor.DisableFontFeature(FontFeatures.Kerning);
+        Assert.That(textBlockSpan.Style.FontFeatures, Has.Length.EqualTo(1));
+        Assert.That(textBlockSpan.Style.FontFeatures[0], Is.EqualTo((FontFeatures.Kerning, false)));
+    }
+
+    [Test]
+    public void FontFeatures_MixedEnableDisable()
+    {
+        var textStyle = TextStyle.Default
+            .EnableFontFeature(FontFeatures.StandardLigatures)
+            .DisableFontFeature(FontFeatures.Kerning)
+            .DisableFontFeature(FontFeatures.DiscretionaryLigatures)
+            .EnableFontFeature(FontFeatures.Kerning);
+        
+        Assert.That(textStyle.FontFeatures, Has.Length.EqualTo(3));
+        Assert.That(textStyle.FontFeatures[0], Is.EqualTo((FontFeatures.Kerning, true)));
+        Assert.That(textStyle.FontFeatures[1], Is.EqualTo((FontFeatures.DiscretionaryLigatures, false)));
+        Assert.That(textStyle.FontFeatures[2], Is.EqualTo((FontFeatures.StandardLigatures, true)));
+    }
+    
+    #endregion
 }

Source/QuestPDF.UnitTests/TextStyleTests.cs

@@ -122,6 +122,67 @@ namespace QuestPDF.UnitTests
     
         #endregion
         
+        #region Font Features
+
+        [Test]
+        public void FontFeatures_Default()
+        {
+            var textStyle = TextStyle.LibraryDefault;
+            Assert.That(textStyle.FontFeatures, Is.Empty);
+        }
+        
+        [Test]
+        public void EnableFontFeature_SingleFeature()
+        {
+            var textStyle = TextStyle.Default
+                .EnableFontFeature(FontFeatures.StandardLigatures);
+            
+            Assert.That(textStyle.FontFeatures, Has.Length.EqualTo(1));
+            Assert.That(textStyle.FontFeatures[0], Is.EqualTo((FontFeatures.StandardLigatures, true)));
+        }
+        
+        [Test]
+        public void DisableFontFeature_SingleFeature()
+        {
+            var textStyle = TextStyle.Default
+                .DisableFontFeature(FontFeatures.Kerning);
+            
+            Assert.That(textStyle.FontFeatures, Has.Length.EqualTo(1));
+            Assert.That(textStyle.FontFeatures[0], Is.EqualTo((FontFeatures.Kerning, false)));
+        }
+        
+        // NOTE: font features applied further down the chain override those applied earlier, and will appear first in the list
+        
+        [Test]
+        public void FontFeatures_MixedEnableDisable()
+        {
+            var textStyle = TextStyle.Default
+                .EnableFontFeature(FontFeatures.StandardLigatures)
+                .DisableFontFeature(FontFeatures.Kerning)
+                .EnableFontFeature(FontFeatures.DiscretionaryLigatures);
+            
+            Assert.That(textStyle.FontFeatures, Has.Length.EqualTo(3));
+            Assert.That(textStyle.FontFeatures[0], Is.EqualTo((FontFeatures.DiscretionaryLigatures, true)));
+            Assert.That(textStyle.FontFeatures[1], Is.EqualTo((FontFeatures.Kerning, false)));
+            Assert.That(textStyle.FontFeatures[2], Is.EqualTo((FontFeatures.StandardLigatures, true)));
+        }
+        
+        [Test]
+        public void FontFeatures_OverrideSameFeature()
+        {
+            var textStyle = TextStyle.Default
+                .EnableFontFeature(FontFeatures.StandardLigatures)
+                .DisableFontFeature(FontFeatures.Kerning)
+                .DisableFontFeature(FontFeatures.Kerning)
+                .DisableFontFeature(FontFeatures.StandardLigatures);
+            
+            Assert.That(textStyle.FontFeatures, Has.Length.EqualTo(2));
+            Assert.That(textStyle.FontFeatures[0], Is.EqualTo((FontFeatures.StandardLigatures, false)));
+            Assert.That(textStyle.FontFeatures[1], Is.EqualTo((FontFeatures.Kerning, false)));
+        }
+        
+        #endregion
+        
         [Test]
         public void ApplyInheritedAndGlobalStyle()
         {