Add test

src/Controls/tests/Xaml.UnitTests/BindingsCompiler.xaml

@@ -5,8 +5,10 @@
 		xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
 		xmlns:sys="clr-namespace:System;assembly=mscorlib"
         xmlns:cmp="clr-namespace:Microsoft.Maui.Controls.Compatibility;assembly=Microsoft.Maui.Controls"
-		x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.BindingsCompiler" >
-	<cmp:StackLayout>
+		x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.BindingsCompiler"
+        x:Name="page"
+        x:DataType="local:GlobalViewModel">
+	<cmp:StackLayout x:Name="stack" x:DataType="{x:Null}">
         <cmp:StackLayout x:DataType="local:MockViewModel">
 			<Label Text="{Binding Text}" x:Name="label0" />
 			<Label Text="{Binding Path=Text}" x:Name="label1" />
@@ -23,6 +25,7 @@
 			<Label Text="{Binding StructModel.Model.Text, Mode=TwoWay}" x:Name="label10" />
             <Label Text="Text for label12" x:Name="label11" />
             <Label Text="{Binding Text, x:DataType=Label, Source={x:Reference label11}}" x:Name="label12" />
+            <Label Text="{Binding BindingContext.GlobalText, Source={x:Reference page}, x:DataType=ContentPage}" x:Name="label13" />
 
 			<Picker
 				ItemsSource="{Binding Items}"

src/Controls/tests/Xaml.UnitTests/BindingsCompiler.xaml.cs

@@ -56,8 +56,9 @@ public void TestCompiledBindings([Values(false, true)]bool useCompiledXaml)
 
 				var layout = new BindingsCompiler(useCompiledXaml)
 				{
-					BindingContext = vm
+					BindingContext = new GlobalViewModel(),
 				};
+				layout.stack.BindingContext = vm;
 				layout.label6.BindingContext = new MockStructViewModel
 				{
 					Model = new MockViewModel
@@ -121,11 +122,14 @@ public void TestCompiledBindings([Values(false, true)]bool useCompiledXaml)
 				}
 
 				//testing invalid bindingcontext type
-				layout.BindingContext = new object();
+				layout.stack.BindingContext = new object();
 				Assert.AreEqual(null, layout.label0.Text);
 
 				//testing source
 				Assert.That(layout.label12.Text, Is.EqualTo("Text for label12"));
+
+				//testing binding with path that cannot be statically compiled (we don't support casts in the Path)
+				Assert.That(layout.label13.Text, Is.EqualTo("Global Text"));
 			}
 
 			[Test] 
@@ -148,6 +152,11 @@ public string Text
 		public MockViewModel Model { get; set; }
 	}
 
+	class GlobalViewModel
+	{
+		public string GlobalText { get; set; } = "Global Text";
+	}
+
 	class MockViewModel : INotifyPropertyChanged
 	{
 		public event PropertyChangedEventHandler PropertyChanged;