Added failing test.

StyleResources cannot currently be found in other style resources
because the style resource binding is evaluated before  the style is
attached to the parent. Described in #492.

tests/Perspex.Markup.Xaml.UnitTests/Perspex.Markup.Xaml.UnitTests.csproj

@@ -174,6 +174,16 @@
   <ItemGroup>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="Xaml\Style1.xaml">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="Xaml\Style2.xaml">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+  </ItemGroup>
   <Choose>
     <When Condition="'$(VisualStudioVersion)' == '10.0' And '$(IsCodedUITest)' == 'True'">
       <ItemGroup>

tests/Perspex.Markup.Xaml.UnitTests/Xaml/Style1.xaml

@@ -0,0 +1,8 @@
+<Style xmlns="https://github.com/perspex"
+       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Style.Resources>
+    <Color x:Key="Red">Red</Color>
+    <Color x:Key="Green">Green</Color>
+    <Color x:Key="Blue">Blue</Color>
+  </Style.Resources>
+</Style>

tests/Perspex.Markup.Xaml.UnitTests/Xaml/Style2.xaml

@@ -0,0 +1,9 @@
+<Style xmlns="https://github.com/perspex"
+       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+       xmlns:mut="https://github.com/perspex/mutable">
+  <Style.Resources>
+    <mut:SolidColorBrush x:Key="RedBrush" Color="{StyleResource Red}"/>
+    <mut:SolidColorBrush x:Key="GreenBrush" Color="{StyleResource Green}"/>
+    <mut:SolidColorBrush x:Key="BlueBrush" Color="{StyleResource Blue}"/>
+  </Style.Resources>
+</Style>

tests/Perspex.Markup.Xaml.UnitTests/Xaml/StyleTests.cs

@@ -198,5 +198,31 @@ namespace Perspex.Markup.Xaml.UnitTests.Xaml
 
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
+
+        [Fact(Skip = "TODO: Issue #492")]
+        public void StyleResource_Can_Be_Found_Across_Xaml_Files()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/perspex'
+        xmlns:mut='https://github.com/perspex/mutable'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Window.Styles>
+        <StyleInclude Source='resm:Perspex.Markup.Xaml.UnitTests.Xaml.Style1.xaml?assembly=Perspex.Markup.Xaml.UnitTests'/>
+        <StyleInclude Source='resm:Perspex.Markup.Xaml.UnitTests.Xaml.Style2.xaml?assembly=Perspex.Markup.Xaml.UnitTests'/>
+    </Window.Styles>
+    <Border Name='border' Background='{StyleResource RedBrush}'/>
+</Window>";
+
+                var loader = new PerspexXamlLoader();
+                var window = (Window)loader.Load(xaml);
+                var border = window.FindControl<Border>("border");
+                var borderBrush = (Perspex.Media.Mutable.SolidColorBrush)border.Background;
+
+                Assert.NotNull(borderBrush);
+                Assert.Equal(0xffff0000, borderBrush.Color.ToUint32());
+            }
+        }
     }
 }