Added failing tests for #3371.

tests/Avalonia.Controls.UnitTests/ImageTests.cs

@@ -13,7 +13,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Measure_Should_Return_Correct_Size_For_No_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.None;
             target.Source = bitmap;
@@ -26,7 +26,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Measure_Should_Return_Correct_Size_For_Fill_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.Fill;
             target.Source = bitmap;
@@ -39,7 +39,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Measure_Should_Return_Correct_Size_For_Uniform_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.Uniform;
             target.Source = bitmap;
@@ -52,7 +52,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Measure_Should_Return_Correct_Size_For_UniformToFill_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.UniformToFill;
             target.Source = bitmap;
@@ -62,10 +62,46 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Size(50, 50), target.DesiredSize);
         }
 
+        [Fact]
+        public void Measure_Should_Return_Correct_Size_For_Infinite_Height()
+        {
+            var bitmap = CreateBitmap(50, 100);
+            var image = new Image();
+            image.Source = bitmap;
+
+            image.Measure(new Size(200, double.PositiveInfinity));
+
+            Assert.Equal(new Size(200, 400), image.DesiredSize);
+        }
+
+        [Fact]
+        public void Measure_Should_Return_Correct_Size_For_Infinite_Width()
+        {
+            var bitmap = CreateBitmap(50, 100);
+            var image = new Image();
+            image.Source = bitmap;
+
+            image.Measure(new Size(double.PositiveInfinity, 400));
+
+            Assert.Equal(new Size(200, 400), image.DesiredSize);
+        }
+
+        [Fact]
+        public void Measure_Should_Return_Correct_Size_For_Infinite_Width_Height()
+        {
+            var bitmap = CreateBitmap(50, 100);
+            var image = new Image();
+            image.Source = bitmap;
+
+            image.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
+
+            Assert.Equal(new Size(50, 100), image.DesiredSize);
+        }
+
         [Fact]
         public void Arrange_Should_Return_Correct_Size_For_No_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.None;
             target.Source = bitmap;
@@ -79,7 +115,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Arrange_Should_Return_Correct_Size_For_Fill_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.Fill;
             target.Source = bitmap;
@@ -93,7 +129,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Arrange_Should_Return_Correct_Size_For_Uniform_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.Uniform;
             target.Source = bitmap;
@@ -107,7 +143,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Arrange_Should_Return_Correct_Size_For_UniformToFill_Stretch()
         {
-            var bitmap = Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(50, 100));
+            var bitmap = CreateBitmap(50, 100);
             var target = new Image();
             target.Stretch = Stretch.UniformToFill;
             target.Source = bitmap;
@@ -117,5 +153,10 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Equal(new Size(25, 100), target.Bounds.Size);
         }
+
+        private IBitmap CreateBitmap(int width, int height)
+        {
+            return Mock.Of<IBitmap>(x => x.PixelSize == new PixelSize(width, height));
+        }
     }
 }