Add an example

src/Microsoft.VisualStudio.LanguageServices.Razor/Editor/DefaultVisualStudioDocumentTrackerFactory.cs

@@ -21,15 +21,22 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
     [Export(typeof(VisualStudioDocumentTrackerFactory))]
     internal class DefaultVisualStudioDocumentTrackerFactory : VisualStudioDocumentTrackerFactory, IWpfTextViewConnectionListener
     {
+        private readonly ForegroundDispatcher _foregroundDispatcher;
         private readonly ProjectSnapshotManager _projectManager;
         private readonly TextBufferProjectService _projectService;
         private readonly Workspace _workspace;
 
         [ImportingConstructor]
         public DefaultVisualStudioDocumentTrackerFactory(
+            ForegroundDispatcher foregroundDispatcher,
             TextBufferProjectService projectService,
             [Import(typeof(VisualStudioWorkspace))] Workspace workspace)
         {
+            if (foregroundDispatcher == null)
+            {
+                throw new ArgumentNullException(nameof(foregroundDispatcher));
+            }
+
             if (projectService == null)
             {
                 throw new ArgumentNullException(nameof(projectService));
@@ -39,7 +46,8 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             {
                 throw new ArgumentNullException(nameof(workspace));
             }
-            
+
+            _foregroundDispatcher = foregroundDispatcher;
             _projectService = projectService;
             _workspace = workspace;
 
@@ -48,10 +56,16 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
 
         // This is only for testing. We want to avoid using the actual Roslyn GetService methods in unit tests.
         internal DefaultVisualStudioDocumentTrackerFactory(
+            ForegroundDispatcher foregroundDispatcher,
             ProjectSnapshotManager projectManager,
             TextBufferProjectService projectService,
             [Import(typeof(VisualStudioWorkspace))] Workspace workspace)
         {
+            if (foregroundDispatcher == null)
+            {
+                throw new ArgumentNullException(nameof(foregroundDispatcher));
+            }
+
             if (projectManager == null)
             {
                 throw new ArgumentNullException(nameof(projectManager));
@@ -67,6 +81,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
                 throw new ArgumentNullException(nameof(workspace));
             }
 
+            _foregroundDispatcher = foregroundDispatcher;
             _projectManager = projectManager;
             _projectService = projectService;
             _workspace = workspace;
@@ -81,6 +96,8 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
                 throw new ArgumentNullException(nameof(textView));
             }
 
+            _foregroundDispatcher.AssertForegroundThread();
+
             // While it's definitely possible to have multiple Razor text buffers attached to the same text view, there's
             // no real scenario for it. This method always returns the tracker for the first Razor text buffer, but the
             // other functionality for this class will maintain state correctly for the other buffers.
@@ -113,7 +130,9 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             {
                 throw new ArgumentNullException(nameof(subjectBuffers));
             }
-            
+
+            _foregroundDispatcher.AssertForegroundThread();
+
             for (var i = 0; i < subjectBuffers.Count; i++)
             {
                 var textBuffer = subjectBuffers[i];
@@ -148,6 +167,8 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
                 throw new ArgumentNullException(nameof(subjectBuffers));
             }
 
+            _foregroundDispatcher.AssertForegroundThread();
+
             // This means a Razor buffer has be detached from this ITextView or the ITextView is closing. Since we keep a 
             // list of all of the open text views for each text buffer, we need to update the tracker.
             //

test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Editor/DefaultVisualStudioDocumentTrackerFactoryTest.cs

@@ -16,7 +16,7 @@ using Xunit;
 
 namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
 {
-    public class DefaultVisualStudioDocumentTrackerFactoryTest
+    public class DefaultVisualStudioDocumentTrackerFactoryTest : ForegroundDispatcherTestBase
     {
         private ProjectSnapshotManager ProjectManager { get; } = Mock.Of<ProjectSnapshotManager>(
             p => p.FindProject(It.IsAny<string>()) == Mock.Of<ProjectSnapshot>() &&
@@ -32,11 +32,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
 
         private IContentType NonRazorContentType { get; } = Mock.Of<IContentType>(c => c.IsOfType(It.IsAny<string>()) == false);
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersConnected_ForNonRazorTextBuffer_DoesNothing()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView = Mock.Of<IWpfTextView>();
 
@@ -52,11 +52,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.False(buffers[0].Properties.ContainsProperty(typeof(VisualStudioDocumentTracker)));
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersConnected_ForRazorTextBufferWithoutTracker_CreatesTrackerAndTracksTextView()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView = Mock.Of<IWpfTextView>();
 
@@ -74,11 +74,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Equal(buffers[0], tracker.TextBuffer);
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersConnected_ForRazorTextBufferWithoutTracker_CreatesTrackerAndTracksTextView_ForMultipleBuffers()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView = Mock.Of<IWpfTextView>();
 
@@ -104,11 +104,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Equal(buffers[2], tracker.TextBuffer);
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersConnected_ForRazorTextBufferWithTracker_DoesNotAddDuplicateTextViewEntry()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView = Mock.Of<IWpfTextView>();
 
@@ -130,11 +130,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Collection(tracker.TextViews, v => Assert.Same(v, textView));
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersConnected_ForRazorTextBufferWithTracker_AddsEntryForADifferentTextView()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView1 = Mock.Of<IWpfTextView>();
             var textView2 = Mock.Of<IWpfTextView>();
@@ -157,11 +157,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Collection(tracker.TextViews, v => Assert.Same(v, textView1), v => Assert.Same(v, textView2));
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersDisconnected_ForAnyTextBufferWithTracker_RemovesTextView()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView1 = Mock.Of<IWpfTextView>();
             var textView2 = Mock.Of<IWpfTextView>();
@@ -194,11 +194,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Collection(tracker.TextViews, v => Assert.Same(v, textView1));
         }
 
-        [Fact]
+        [ForegroundFact]
         public void SubjectBuffersDisconnected_ForAnyTextBufferWithoutTracker_DoesNothing()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var textView = Mock.Of<IWpfTextView>();
 
@@ -214,11 +214,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.False(buffers[0].Properties.ContainsProperty(typeof(VisualStudioDocumentTracker)));
         }
 
-        [Fact]
+        [ForegroundFact]
         public void GetTracker_ForRazorTextBufferWithTracker_ReturnsTheFirstTracker()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var buffers = new Collection<ITextBuffer>()
             {
@@ -241,11 +241,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor.Editor
             Assert.Same(tracker, result);
         }
 
-        [Fact]
+        [ForegroundFact]
         public void GetTracker_WithoutRazorBuffer_ReturnsNull()
         {
             // Arrange
-            var factory = new DefaultVisualStudioDocumentTrackerFactory(ProjectManager, ProjectService, Workspace);
+            var factory = new DefaultVisualStudioDocumentTrackerFactory(Dispatcher, ProjectManager, ProjectService, Workspace);
 
             var buffers = new Collection<ITextBuffer>();
 

test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Xunit/ForegroundFactAttribute.cs

@@ -8,7 +8,7 @@ namespace Xunit
 {
     // Similar to WpfFactAttribute https://github.com/xunit/samples.xunit/blob/969d9f7e887836f01a6c525324bf3db55658c28f/STAExamples/WpfFactAttribute.cs
     [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-    [XunitTestCaseDiscoverer("Xunit.ForegroundFactAttribute", "Microsoft.VisualStudio.LanguageServices.Razor")]
+    [XunitTestCaseDiscoverer("Xunit.ForegroundFactDiscoverer", "Microsoft.VisualStudio.LanguageServices.Razor.Test")]
     internal class ForegroundFactAttribute : FactAttribute
     {
     }

test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Xunit/ForegroundFactDiscoverer.cs

@@ -1,117 +1,25 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using System.Collections.Generic;
-using System.ComponentModel;
+using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using System.Windows.Threading;
 using Xunit.Abstractions;
 using Xunit.Sdk;
 
 namespace Xunit
 {
-    internal class ForegroundFactTestCase : LongLivedMarshalByRefObject, IXunitTestCase
+    internal class ForegroundFactDiscoverer : IXunitTestCaseDiscoverer
     {
-        private IXunitTestCase _inner;
+        readonly FactDiscoverer _inner;
 
-        [EditorBrowsable(EditorBrowsableState.Never)]
+        public ForegroundFactDiscoverer(IMessageSink diagnosticMessageSink)
-        [Obsolete("Called by the de-serializer", error: true)]
-        public ForegroundFactTestCase()
         {
+            _inner = new FactDiscoverer(diagnosticMessageSink);
         }
 
-        public ForegroundFactTestCase(IXunitTestCase testCase)
+        public IEnumerable<IXunitTestCase> Discover(ITestFrameworkDiscoveryOptions discoveryOptions, ITestMethod testMethod, IAttributeInfo factAttribute)
         {
-            _inner = testCase;
+            return _inner.Discover(discoveryOptions, testMethod, factAttribute).Select(t => new ForegroundFactTestCase(t));
-        }
-
-        public string DisplayName => _inner.DisplayName;
-
-        public IMethodInfo Method => _inner.Method;
-
-        public string SkipReason => _inner.SkipReason;
-
-        public ISourceInformation SourceInformation
-        {
-            get => _inner.SourceInformation;
-            set => _inner.SourceInformation = value;
-        }
-
-        public ITestMethod TestMethod => _inner.TestMethod;
-
-        public object[] TestMethodArguments => _inner.TestMethodArguments;
-
-        public Dictionary<string, List<string>> Traits => _inner.Traits;
-
-        public string UniqueID => _inner.UniqueID;
-
-        public void Deserialize(IXunitSerializationInfo info)
-        {
-            _inner = info.GetValue<IXunitTestCase>("InnerTestCase");
-        }
-
-        public void Serialize(IXunitSerializationInfo info)
-        {
-            info.AddValue("InnerTestCase", _inner);
-        }
-
-        public Task<RunSummary> RunAsync(
-            IMessageSink diagnosticMessageSink,
-            IMessageBus messageBus,
-            object[] constructorArguments,
-            ExceptionAggregator aggregator,
-            CancellationTokenSource cancellationTokenSource)
-        {
-            var tcs = new TaskCompletionSource<RunSummary>();
-            var thread = new Thread(() =>
-            {
-                try
-                {
-                    SynchronizationContext.SetSynchronizationContext(new DispatcherSynchronizationContext());
-                    
-                    var worker = _inner.RunAsync(diagnosticMessageSink, messageBus, constructorArguments, aggregator, cancellationTokenSource);
-
-                    Exception caught = null;
-                    var frame = new DispatcherFrame();
-                    Task.Run(async () =>
-                    {
-                        try
-                        {
-                            await worker;
-                        }
-                        catch (Exception ex)
-                        {
-                            caught = ex;
-                        }
-                        finally
-                        {
-                            frame.Continue = false;
-                        }
-                    });
-
-                    Dispatcher.PushFrame(frame);
-                    
-                    if (caught == null)
-                    {
-                        tcs.SetException(caught);
-                    }
-                    else
-                    {
-                        tcs.SetResult(worker.Result);
-                    }
-                }
-                catch (Exception e)
-                {
-                    tcs.SetException(e);
-                }
-            });
-
-            thread.SetApartmentState(ApartmentState.STA);
-            thread.Start();
-
-            return tcs.Task;
         }
     }
-}
+}

test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Xunit/ForegroundFactTestCase.cs

@@ -0,0 +1,117 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows.Threading;
+using Xunit.Abstractions;
+using Xunit.Sdk;
+
+namespace Xunit
+{
+    internal class ForegroundFactTestCase : LongLivedMarshalByRefObject, IXunitTestCase
+    {
+        private IXunitTestCase _inner;
+
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        [Obsolete("Called by the de-serializer", error: true)]
+        public ForegroundFactTestCase()
+        {
+        }
+
+        public ForegroundFactTestCase(IXunitTestCase testCase)
+        {
+            _inner = testCase;
+        }
+
+        public string DisplayName => _inner.DisplayName;
+
+        public IMethodInfo Method => _inner.Method;
+
+        public string SkipReason => _inner.SkipReason;
+
+        public ISourceInformation SourceInformation
+        {
+            get => _inner.SourceInformation;
+            set => _inner.SourceInformation = value;
+        }
+
+        public ITestMethod TestMethod => _inner.TestMethod;
+
+        public object[] TestMethodArguments => _inner.TestMethodArguments;
+
+        public Dictionary<string, List<string>> Traits => _inner.Traits;
+
+        public string UniqueID => _inner.UniqueID;
+
+        public void Deserialize(IXunitSerializationInfo info)
+        {
+            _inner = info.GetValue<IXunitTestCase>("InnerTestCase");
+        }
+
+        public void Serialize(IXunitSerializationInfo info)
+        {
+            info.AddValue("InnerTestCase", _inner);
+        }
+
+        public Task<RunSummary> RunAsync(
+            IMessageSink diagnosticMessageSink,
+            IMessageBus messageBus,
+            object[] constructorArguments,
+            ExceptionAggregator aggregator,
+            CancellationTokenSource cancellationTokenSource)
+        {
+            var tcs = new TaskCompletionSource<RunSummary>();
+            var thread = new Thread(() =>
+            {
+                try
+                {
+                    SynchronizationContext.SetSynchronizationContext(new DispatcherSynchronizationContext());
+                    
+                    var worker = _inner.RunAsync(diagnosticMessageSink, messageBus, constructorArguments, aggregator, cancellationTokenSource);
+
+                    Exception caught = null;
+                    var frame = new DispatcherFrame();
+                    Task.Run(async () =>
+                    {
+                        try
+                        {
+                            await worker;
+                        }
+                        catch (Exception ex)
+                        {
+                            caught = ex;
+                        }
+                        finally
+                        {
+                            frame.Continue = false;
+                        }
+                    });
+
+                    Dispatcher.PushFrame(frame);
+
+                    if (caught == null)
+                    {
+                        tcs.SetResult(worker.Result);
+                    }
+                    else
+                    { 
+                        tcs.SetException(caught);
+                    }
+                }
+                catch (Exception e)
+                {
+                    tcs.SetException(e);
+                }
+            });
+
+            thread.SetApartmentState(ApartmentState.STA);
+            thread.Start();
+
+            return tcs.Task;
+        }
+    }
+}