mark the test as windows only

Author: tocsoft

tests/ImageSharp.Drawing.Tests/Issues/Issue-54.cs

@@ -1,6 +1,8 @@
 using System;
+using System.Runtime.InteropServices;
 using SixLabors.Fonts;
 using SixLabors.ImageSharp.Drawing.Processing;
+using SixLabors.ImageSharp.Drawing.Tests.TestUtilities.Attributes;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 using Xunit;
@@ -9,7 +11,7 @@ namespace SixLabors.ImageSharp.Drawing.Tests.Issues
 {
     public class Issue_54
     {
-        [Fact]
+        [WindowsFact]
         public void CanDrawWithoutMemoryException()
         {
             int width = 768;
@@ -39,15 +41,15 @@ public void CanDrawWithoutMemoryException()
 
                 // Draw the text
                 image.Mutate(x => x.DrawText(options, text, font, brush, pen, new PointF(0, 100)));
-            } 
+            }
         }
 
         [Fact]
         public void PenMustHaveAWidthGraterThanZero()
         {
             ArgumentOutOfRangeException ex = Assert.Throws<ArgumentOutOfRangeException>(() =>
             {
-                IPen pen = new Pen(Color.White, 0); 
+                IPen pen = new Pen(Color.White, 0);
             });
 
             Assert.Equal("Parameter \"width\" (System.Single) must be greater than 0, was 0 (Parameter 'width')", ex.Message);

tests/ImageSharp.Drawing.Tests/TestUtilities/Attributes/PlatformFactAttribute.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using Xunit;
+
+namespace SixLabors.ImageSharp.Drawing.Tests.TestUtilities.Attributes
+{
+    public class PlatformFactAttribute : FactAttribute
+    {
+        public PlatformFactAttribute(OSPlatform platform)
+        {
+            if (!RuntimeInformation.IsOSPlatform(platform))
+            {
+                this.Skip = $"Platform specific test, runs only on '{platform}'";
+            }
+        }
+    }
+
+    public class WindowsFactAttribute : PlatformFactAttribute
+    {
+        public WindowsFactAttribute() : base(OSPlatform.Windows)
+        {
+        }
+    }
+}