Add a smoke test

Avalonia.sln

@@ -226,6 +226,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.Markup.Xaml.Loader
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.ReactiveUI.Events", "src\Avalonia.ReactiveUI.Events\Avalonia.ReactiveUI.Events.csproj", "{28F18757-C3E6-4BBE-A37D-11BA2AB9177C}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.ReactiveUI.Events.UnitTests", "tests\Avalonia.ReactiveUI.Events.UnitTests\Avalonia.ReactiveUI.Events.UnitTests.csproj", "{780AC0FE-8DD2-419F-A1DC-AC7E3EB393F7}"
+EndProject
 Global
 	GlobalSection(SharedMSBuildProjectFiles) = preSolution
 		src\Shared\RenderHelpers\RenderHelpers.projitems*{3c4c0cb4-0c0f-4450-a37b-148c84ff905f}*SharedItemsImports = 13
@@ -2120,6 +2122,7 @@ Global
 		{351337F5-D66F-461B-A957-4EF60BDB4BA6} = {C5A00AC3-B34C-4564-9BDD-2DA473EF4D8B}
 		{3C84E04B-36CF-4D0D-B965-C26DD649D1F3} = {A0CC0258-D18C-4AB3-854F-7101680FC3F9}
 		{909A8CBD-7D0E-42FD-B841-022AD8925820} = {8B6A8209-894F-4BA1-B880-965FD453982C}
+		{780AC0FE-8DD2-419F-A1DC-AC7E3EB393F7} = {C5A00AC3-B34C-4564-9BDD-2DA473EF4D8B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {87366D66-1391-4D90-8999-95A620AD786A}

dirs.proj

@@ -7,6 +7,7 @@
     <ProjectReference Remove="**/*.shproj" />
     <ProjectReference Remove="src/Markup/Avalonia.Markup.Xaml/PortableXaml/**/*.*proj" />
     <ProjectReference Remove="src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github/**/*.*proj" />
+    <ProjectReference Remove="tests/Avalonia.ReactiveUI.Events.UnitTests/Avalonia.ReactiveUI.Events.UnitTests.csproj" />
   </ItemGroup>
   <!--<ItemGroup Condition="!Exists('$(MSBuildExtensionsPath)\Xamarin\Android')">-->
   <ItemGroup>

nukebuild/Build.cs

@@ -240,6 +240,7 @@ partial class Build : NukeBuild
             RunCoreTest("Avalonia.Visuals.UnitTests");
             RunCoreTest("Avalonia.Skia.UnitTests");
             RunCoreTest("Avalonia.ReactiveUI.UnitTests");
+            RunCoreTest("Avalonia.ReactiveUI.Events.UnitTests");
         });
 
     Target RunRenderTests => _ => _

tests/Avalonia.ReactiveUI.Events.UnitTests/Avalonia.ReactiveUI.Events.UnitTests.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+  <Import Project="..\..\build\UnitTests.NetCore.targets" />
+  <Import Project="..\..\build\Moq.props" />
+  <Import Project="..\..\build\XUnit.props" />
+  <Import Project="..\..\build\Rx.props" />
+  <Import Project="..\..\build\Microsoft.Reactive.Testing.props" />
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Markup\Avalonia.Markup.Xaml.Loader\Avalonia.Markup.Xaml.Loader.csproj" />
+    <ProjectReference Include="..\Avalonia.UnitTests\Avalonia.UnitTests.csproj" />
+    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI.Events\Avalonia.ReactiveUI.Events.csproj" />
+  </ItemGroup>
+</Project>

tests/Avalonia.ReactiveUI.Events.UnitTests/BasicControlEventsTest.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Reactive.Linq;
+using Avalonia.Controls;
+using Avalonia.UnitTests;
+using Xunit;
+
+namespace Avalonia.ReactiveUI.Events.UnitTests
+{
+    public class BasicControlEventsTest
+    {
+        public class EventsControl : UserControl
+        {
+            public bool IsAttached { get; private set; }
+
+            public EventsControl()
+            {
+                var attached = this
+                    .Events()
+                    .AttachedToVisualTree
+                    .Select(args => true);
+
+                this.Events()
+                    .DetachedFromVisualTree
+                    .Select(args => false)
+                    .Merge(attached)
+                    .Subscribe(marker => IsAttached = marker);
+            }
+        }
+
+        [Fact]
+        public void Should_Generate_Events_Wrappers()
+        {
+            var root = new TestRoot();
+            var control = new EventsControl();
+            Assert.False(control.IsAttached);
+
+            root.Child = control;
+            Assert.True(control.IsAttached);
+
+            root.Child = null;
+            Assert.False(control.IsAttached);
+        }
+    }
+}