Add unit test

Author: JimBobSquarePants

tests/ImageSharp.Drawing.Tests/Shapes/TextBuilderTests.cs

@@ -0,0 +1,34 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.Numerics;
+using SixLabors.Fonts;
+using Xunit;
+
+namespace SixLabors.ImageSharp.Drawing.Tests.Shapes
+{
+    public class TextBuilderTests
+    {
+        [Fact]
+        public void TextBuilder_Bounds_AreCorrect()
+        {
+            Vector2 position = new(5, 5);
+            var options = new TextOptions(TestFontUtilities.GetFont(TestFonts.OpenSans, 16))
+            {
+                Origin = position
+            };
+
+            string text = "Hello World";
+
+            IPathCollection glyphs = TextBuilder.GenerateGlyphs(text, options);
+
+            RectangleF builderBounds = glyphs.Bounds;
+            FontRectangle measuredBounds = TextMeasurer.MeasureBounds(text, options);
+
+            Assert.Equal(measuredBounds.X, builderBounds.X);
+            Assert.Equal(measuredBounds.Y, builderBounds.Y);
+            Assert.Equal(measuredBounds.Width, builderBounds.Width);
+            Assert.Equal(measuredBounds.Height, builderBounds.Height);
+        }
+    }
+}