Reorganize file tracker

This is precursor to a much bigger change. Pushing out some of the
changes that have broad impact early to make it easier to review the
real change.

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultDocumentSnapshot.cs

@@ -39,15 +39,15 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             return State.GeneratedOutput.GetGeneratedOutputInitializationTask(Project, this);
         }
 
-        public override bool TryGetGeneratedOutput(out RazorCodeDocument results)
+        public override bool TryGetGeneratedOutput(out RazorCodeDocument result)
         {
             if (State.GeneratedOutput.IsResultAvailable)
             {
-                results = State.GeneratedOutput.GetGeneratedOutputInitializationTask(Project, this).Result;
+                result = State.GeneratedOutput.GetGeneratedOutputInitializationTask(Project, this).Result;
                 return true;
             }
 
-            results = null;
+            result = null;
             return false;
         }
     }

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshot.cs

@@ -69,15 +69,15 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             return State.TagHelpers.GetTagHelperInitializationTask(this);
         }
 
-        public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> results)
+        public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> result)
         {
             if (State.TagHelpers.IsResultAvailable)
             {
-                results = State.TagHelpers.GetTagHelperInitializationTask(this).Result;
+                result = State.TagHelpers.GetTagHelperInitializationTask(this).Result;
                 return true;
             }
 
-            results = null;
+            result = null;
             return false;
         }
     }

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshotManager.cs

@@ -149,7 +149,7 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
 
             if (_projects.TryGetValue(hostProject.FilePath, out var entry))
             {
-                var state = entry.State.AddHostDocument(document);
+                var state = entry.State.WithAddedHostDocument(document);
 
                 // Document updates can no-op.
                 if (!object.ReferenceEquals(state, entry.State))
@@ -175,7 +175,7 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             _foregroundDispatcher.AssertForegroundThread();
             if (_projects.TryGetValue(hostProject.FilePath, out var entry))
             {
-                var state = entry.State.RemoveHostDocument(document);
+                var state = entry.State.WithRemovedHostDocument(document);
 
                 // Document updates can no-op.
                 if (!object.ReferenceEquals(state, entry.State))

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentSnapshot.cs

@@ -14,6 +14,6 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
 
         public abstract Task<RazorCodeDocument> GetGeneratedOutputAsync();
 
-        public abstract bool TryGetGeneratedOutput(out RazorCodeDocument results);
+        public abstract bool TryGetGeneratedOutput(out RazorCodeDocument result);
     }
 }

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/EphemeralProjectSnapshot.cs

@@ -66,9 +66,9 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             return EmptyTagHelpers;
         }
 
-        public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> results)
+        public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> result)
         {
-            results = EmptyTagHelpers.Result;
+            result = EmptyTagHelpers.Result;
             return true;
         }
 

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshot.cs

@@ -27,6 +27,6 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
 
         public abstract Task<IReadOnlyList<TagHelperDescriptor>> GetTagHelpersAsync();
 
-        public abstract bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> results);
+        public abstract bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> result);
     }
 }

src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs

@@ -126,7 +126,7 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             }
         }
 
-        public ProjectState AddHostDocument(HostDocument hostDocument)
+        public ProjectState WithAddedHostDocument(HostDocument hostDocument)
         {
             if (hostDocument == null)
             {
@@ -153,7 +153,7 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             return state;
         }
 
-        public ProjectState RemoveHostDocument(HostDocument hostDocument)
+        public ProjectState WithRemovedHostDocument(HostDocument hostDocument)
         {
             if (hostDocument == null)
             {

src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceBase.cs

@@ -86,7 +86,7 @@ namespace Microsoft.CodeAnalysis.Remote.Razor
                 throw new NotImplementedException();
             }
 
-            public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> results)
+            public override bool TryGetTagHelpers(out IReadOnlyList<TagHelperDescriptor> result)
             {
                 throw new NotImplementedException();
             }

src/Microsoft.VisualStudio.Editor.Razor/DefaultImportDocumentManager.cs

@@ -4,10 +4,10 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.IO;
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Razor;
+using Microsoft.VisualStudio.Editor.Razor.Documents;
 
 namespace Microsoft.VisualStudio.Editor.Razor
 {

src/Microsoft.VisualStudio.Editor.Razor/DefaultImportDocumentManagerFactory.cs

@@ -6,6 +6,7 @@ using System.Composition;
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Razor;
+using Microsoft.VisualStudio.Editor.Razor.Documents;
 
 namespace Microsoft.VisualStudio.Editor.Razor
 {
@@ -34,7 +35,7 @@ namespace Microsoft.VisualStudio.Editor.Razor
             }
 
             var errorReporter = languageServices.WorkspaceServices.GetRequiredService<ErrorReporter>();
-            var fileChangeTrackerFactory = languageServices.GetRequiredService<FileChangeTrackerFactory>();
+            var fileChangeTrackerFactory = languageServices.WorkspaceServices.GetRequiredService<FileChangeTrackerFactory>();
 
             return new DefaultImportDocumentManager(_foregroundDispatcher, errorReporter, fileChangeTrackerFactory);
         }

src/Microsoft.VisualStudio.Editor.Razor/Documents/DefaultFileChangeTracker.cs

@@ -0,0 +1,37 @@
+// 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;
+
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
+{
+    // A noop implementation for non-ide cases
+    internal class DefaultFileChangeTracker : FileChangeTracker
+    {
+        public override event EventHandler<FileChangeEventArgs> Changed;
+
+        public DefaultFileChangeTracker(string filePath)
+        {
+            if (filePath == null)
+            {
+                throw new ArgumentNullException(nameof(filePath));
+            }
+
+            FilePath = filePath;
+
+            GC.KeepAlive(Changed);
+        }
+
+        public override string FilePath { get; }
+
+        public override void StartListening()
+        {
+            // Do nothing
+        }
+
+        public override void StopListening()
+        {
+            // Do nothing
+        }
+    }
+}

src/Microsoft.VisualStudio.Editor.Razor/Documents/DefaultFileChangeTrackerFactory.cs

@@ -0,0 +1,22 @@
+// 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 Microsoft.CodeAnalysis.Host.Mef;
+
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
+{
+    [ExportWorkspaceService(typeof(FileChangeTrackerFactory), layer: ServiceLayer.Editor)]
+    internal class DefaultFileChangeTrackerFactory : FileChangeTrackerFactory
+    {
+        public override FileChangeTracker Create(string filePath)
+        {
+            if (filePath == null)
+            {
+                throw new ArgumentNullException(nameof(filePath));
+            }
+
+            return new DefaultFileChangeTracker(filePath);
+        }
+    }
+}

src/Microsoft.VisualStudio.Editor.Razor/Documents/FileChangeEventArgs.cs

@@ -3,7 +3,7 @@
 
 using System;
 
-namespace Microsoft.VisualStudio.Editor.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     internal sealed class FileChangeEventArgs : EventArgs
     {

src/Microsoft.VisualStudio.Editor.Razor/Documents/FileChangeKind.cs

@@ -1,7 +1,7 @@
 // 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.
 
-namespace Microsoft.VisualStudio.Editor.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     internal enum FileChangeKind
     {

src/Microsoft.VisualStudio.Editor.Razor/Documents/FileChangeTracker.cs

@@ -3,7 +3,7 @@
 
 using System;
 
-namespace Microsoft.VisualStudio.Editor.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     internal abstract class FileChangeTracker
     {

src/Microsoft.VisualStudio.Editor.Razor/Documents/FileChangeTrackerFactory.cs

@@ -3,9 +3,9 @@
 
 using Microsoft.CodeAnalysis.Host;
 
-namespace Microsoft.VisualStudio.Editor.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    internal abstract class FileChangeTrackerFactory : ILanguageService
+    internal abstract class FileChangeTrackerFactory : IWorkspaceService
     {
         public abstract FileChangeTracker Create(string filePath);
     }

src/Microsoft.VisualStudio.Editor.Razor/ImportChangedEventArgs.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using Microsoft.VisualStudio.Editor.Razor.Documents;
 
 namespace Microsoft.VisualStudio.Editor.Razor
 {

src/Microsoft.VisualStudio.LanguageServices.Razor/Documents/VisaulStudioFileChangeTracker.cs

@@ -2,15 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 using System.Runtime.InteropServices;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.Shell.Interop;
 
-namespace Microsoft.VisualStudio.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    internal class DefaultFileChangeTracker : FileChangeTracker, IVsFileChangeEvents
+    internal class VisualStudioFileChangeTracker : FileChangeTracker, IVsFileChangeEvents
     {
         private const uint FileChangeFlags = (uint)(_VSFILECHANGEFLAGS.VSFILECHG_Time | _VSFILECHANGEFLAGS.VSFILECHG_Size | _VSFILECHANGEFLAGS.VSFILECHG_Del | _VSFILECHANGEFLAGS.VSFILECHG_Add);
 
@@ -21,7 +19,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
 
         public override event EventHandler<FileChangeEventArgs> Changed;
 
-        public DefaultFileChangeTracker(
+        public VisualStudioFileChangeTracker(
             string filePath,
             ForegroundDispatcher foregroundDispatcher,
             ErrorReporter errorReporter,

src/Microsoft.VisualStudio.LanguageServices.Razor/Documents/VisualStudioFileChangeTrackerFactory.cs

@@ -3,18 +3,17 @@
 
 using System;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.Shell.Interop;
 
-namespace Microsoft.VisualStudio.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    internal partial class DefaultFileChangeTrackerFactory : FileChangeTrackerFactory
+    internal class VisualStudioFileChangeTrackerFactory : FileChangeTrackerFactory
     {
         private readonly ForegroundDispatcher _foregroundDispatcher;
         private readonly ErrorReporter _errorReporter;
         private readonly IVsFileChangeEx _fileChangeService;
 
-        public DefaultFileChangeTrackerFactory(
+        public VisualStudioFileChangeTrackerFactory(
             ForegroundDispatcher foregroundDispatcher,
             ErrorReporter errorReporter, 
             IVsFileChangeEx fileChangeService)
@@ -46,7 +45,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(filePath));
             }
 
-            var fileChangeTracker = new DefaultFileChangeTracker(filePath, _foregroundDispatcher, _errorReporter, _fileChangeService);
+            var fileChangeTracker = new VisualStudioFileChangeTracker(filePath, _foregroundDispatcher, _errorReporter, _fileChangeService);
             return fileChangeTracker;
         }
     }

src/Microsoft.VisualStudio.LanguageServices.Razor/Documents/VisualStudioFileChangeTrackerFactoryFactory.cs

@@ -6,21 +6,20 @@ using System.Composition;
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.Shell;
 using Microsoft.VisualStudio.Shell.Interop;
 
-namespace Microsoft.VisualStudio.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     [Shared]
-    [ExportLanguageServiceFactory(typeof(FileChangeTrackerFactory), RazorLanguage.Name, ServiceLayer.Default)]
-    internal class DefaultFileChangeTrackerFactoryFactory : ILanguageServiceFactory
+    [ExportWorkspaceServiceFactory(typeof(FileChangeTrackerFactory), ServiceLayer.Host)]
+    internal class VisualStudioFileChangeTrackerFactoryFactory : IWorkspaceServiceFactory
     {
         private readonly IVsFileChangeEx _fileChangeService;
         private readonly ForegroundDispatcher _foregroundDispatcher;
 
         [ImportingConstructor]
-        public DefaultFileChangeTrackerFactoryFactory(ForegroundDispatcher foregroundDispatcher, SVsServiceProvider serviceProvider)
+        public VisualStudioFileChangeTrackerFactoryFactory(ForegroundDispatcher foregroundDispatcher, SVsServiceProvider serviceProvider)
         {
             if (foregroundDispatcher == null)
             {
@@ -35,16 +34,15 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
             _foregroundDispatcher = foregroundDispatcher;
             _fileChangeService = serviceProvider.GetService(typeof(SVsFileChangeEx)) as IVsFileChangeEx;
         }
-
-        public ILanguageService CreateLanguageService(HostLanguageServices languageServices)
+        public IWorkspaceService CreateService(HostWorkspaceServices workspaceServices)
         {
-            if (languageServices == null)
+            if (workspaceServices == null)
             {
-                throw new ArgumentNullException(nameof(languageServices));
+                throw new ArgumentNullException(nameof(workspaceServices));
             }
 
-            var errorReporter = languageServices.WorkspaceServices.GetRequiredService<ErrorReporter>();
-            return new DefaultFileChangeTrackerFactory(_foregroundDispatcher, errorReporter, _fileChangeService);
+            var errorReporter = workspaceServices.GetRequiredService<ErrorReporter>();
+            return new VisualStudioFileChangeTrackerFactory(_foregroundDispatcher, errorReporter, _fileChangeService);
         }
     }
 }

src/Microsoft.VisualStudio.Mac.LanguageServices.Razor/Documents/VisualStudioMacFileChangeTracker.cs

@@ -3,12 +3,11 @@
 
 using System;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 using MonoDevelop.Core;
 
-namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    internal class DefaultFileChangeTracker : FileChangeTracker
+    internal class VisualStudioMacFileChangeTracker : FileChangeTracker
     {
         private readonly ForegroundDispatcher _foregroundDispatcher;
         private readonly string _normalizedFilePath;
@@ -16,7 +15,7 @@ namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
 
         public override event EventHandler<FileChangeEventArgs> Changed;
 
-        public DefaultFileChangeTracker(
+        public VisualStudioMacFileChangeTracker(
             string filePath,
             ForegroundDispatcher foregroundDispatcher)
         {

src/Microsoft.VisualStudio.Mac.LanguageServices.Razor/Documents/VisualStudioMacFileChangeTrackerFactory.cs

@@ -3,15 +3,14 @@
 
 using System;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 
-namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    internal class DefaultFileChangeTrackerFactory : FileChangeTrackerFactory
+    internal class VisualStudioMacFileChangeTrackerFactory : FileChangeTrackerFactory
     {
         private readonly ForegroundDispatcher _foregroundDispatcher;
 
-        public DefaultFileChangeTrackerFactory(ForegroundDispatcher foregroundDispatcher)
+        public VisualStudioMacFileChangeTrackerFactory(ForegroundDispatcher foregroundDispatcher)
         {
             if (foregroundDispatcher == null)
             {
@@ -28,7 +27,7 @@ namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
                 throw new ArgumentException(Resources.ArgumentCannotBeNullOrEmpty, nameof(filePath));
             }
 
-            var fileChangeTracker = new DefaultFileChangeTracker(filePath, _foregroundDispatcher);
+            var fileChangeTracker = new VisualStudioMacFileChangeTracker(filePath, _foregroundDispatcher);
             return fileChangeTracker;
         }
     }

src/Microsoft.VisualStudio.Mac.LanguageServices.Razor/Documents/VisualStudioMacFileChangeTrackerFactoryFactory.cs

@@ -6,18 +6,17 @@ using System.Composition;
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 
-namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     [Shared]
-    [ExportLanguageServiceFactory(typeof(FileChangeTrackerFactory), RazorLanguage.Name, ServiceLayer.Default)]
-    internal class DefaultFileChangeTrackerFactoryFactory : ILanguageServiceFactory
+    [ExportWorkspaceService(typeof(FileChangeTrackerFactory), ServiceLayer.Host)]
+    internal class VisualStudioMacFileChangeTrackerFactoryFactory : IWorkspaceServiceFactory
     {
         private readonly ForegroundDispatcher _foregroundDispatcher;
 
         [ImportingConstructor]
-        public DefaultFileChangeTrackerFactoryFactory(ForegroundDispatcher foregroundDispatcher)
+        public VisualStudioMacFileChangeTrackerFactoryFactory(ForegroundDispatcher foregroundDispatcher)
         {
             if (foregroundDispatcher == null)
             {
@@ -27,14 +26,14 @@ namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
             _foregroundDispatcher = foregroundDispatcher;
         }
 
-        public ILanguageService CreateLanguageService(HostLanguageServices languageServices)
+        public IWorkspaceService CreateService(HostWorkspaceServices workspaceServices)
         {
-            if (languageServices == null)
+            if (workspaceServices == null)
             {
-                throw new ArgumentNullException(nameof(languageServices));
+                throw new ArgumentNullException(nameof(workspaceServices));
             }
 
-            return new DefaultFileChangeTrackerFactory(_foregroundDispatcher);
+            return new VisualStudioMacFileChangeTrackerFactory(_foregroundDispatcher);
         }
     }
 }

test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultProjectSnapshotTest.cs

@@ -77,9 +77,9 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var state = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[0])
-                .AddHostDocument(Documents[1])
-                .AddHostDocument(Documents[2]);
+                .WithAddedHostDocument(Documents[0])
+                .WithAddedHostDocument(Documents[1])
+                .WithAddedHostDocument(Documents[2]);
             var snapshot = new DefaultProjectSnapshot(state);
 
             // Act

test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs

@@ -106,7 +106,7 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject);
 
             // Act
-            var state = original.AddHostDocument(Documents[0]);
+            var state = original.WithAddedHostDocument(Documents[0]);
 
             // Assert
             Assert.NotEqual(original.Version, state.Version);
@@ -121,11 +121,11 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Act
-            var state = original.AddHostDocument(Documents[0]);
+            var state = original.WithAddedHostDocument(Documents[0]);
 
             // Assert
             Assert.NotEqual(original.Version, state.Version);
@@ -142,15 +142,15 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
             GC.KeepAlive(original.TagHelpers);
 
             // Act
-            var state = original.AddHostDocument(Documents[0]);
+            var state = original.WithAddedHostDocument(Documents[0]);
 
             // Assert
             Assert.Same(original.ProjectEngine, state.ProjectEngine);
@@ -165,11 +165,11 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Act
-            var state = original.AddHostDocument(new HostDocument(Documents[1].FilePath, "SomePath.cshtml"));
+            var state = original.WithAddedHostDocument(new HostDocument(Documents[1].FilePath, "SomePath.cshtml"));
 
             // Assert
             Assert.Same(original, state);
@@ -180,11 +180,11 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Act
-            var state = original.RemoveHostDocument(Documents[1]);
+            var state = original.WithRemovedHostDocument(Documents[1]);
 
             // Assert
             Assert.NotEqual(original.Version, state.Version);
@@ -199,15 +199,15 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
             GC.KeepAlive(original.TagHelpers);
 
             // Act
-            var state = original.RemoveHostDocument(Documents[2]);
+            var state = original.WithRemovedHostDocument(Documents[2]);
 
             // Assert
             Assert.Same(original.ProjectEngine, state.ProjectEngine);
@@ -221,11 +221,11 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Act
-            var state = original.RemoveHostDocument(Documents[0]);
+            var state = original.WithRemovedHostDocument(Documents[0]);
 
             // Assert
             Assert.Same(original, state);
@@ -236,8 +236,8 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
@@ -262,8 +262,8 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
@@ -281,8 +281,8 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
@@ -307,8 +307,8 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, null)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);
@@ -333,8 +333,8 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
         {
             // Arrange
             var original = new ProjectState(Workspace.Services, HostProject, WorkspaceProject)
-                .AddHostDocument(Documents[2])
-                .AddHostDocument(Documents[1]);
+                .WithAddedHostDocument(Documents[2])
+                .WithAddedHostDocument(Documents[1]);
 
             // Force init
             GC.KeepAlive(original.ProjectEngine);

test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultImportDocumentManagerIntegrationTest.cs

@@ -1,16 +1,14 @@
 // 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.IO;
-using Microsoft.AspNetCore.Mvc.Razor.Extensions;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Moq;
 using Xunit;
 
-namespace Microsoft.VisualStudio.Editor.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
     public class DefaultImportDocumentManagerIntegrationTest : ForegroundDispatcherTestBase
     {

test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultImportDocumentManagerTest.cs

@@ -6,6 +6,7 @@ using System.IO;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
+using Microsoft.VisualStudio.Editor.Razor.Documents;
 using Moq;
 using Xunit;
 

test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultVisualStudioDocumentTrackerTest.cs

@@ -10,6 +10,7 @@ using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.Editor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
+using Microsoft.VisualStudio.Editor.Razor.Documents;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Text.Editor;
 using Microsoft.VisualStudio.Utilities;

test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Documents/VisualStudioFileChangeTrackerTest.cs

@@ -3,14 +3,13 @@
 
 using System;
 using Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.Shell.Interop;
 using Moq;
 using Xunit;
 
-namespace Microsoft.VisualStudio.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    public class DefaultFileChangeTrackerTest : ForegroundDispatcherTestBase
+    public class VisualStudioFileChangeTrackerTest : ForegroundDispatcherTestBase
     {
         private ErrorReporter ErrorReporter { get; } = new DefaultErrorReporter();
 
@@ -24,7 +23,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
                 .Setup(f => f.AdviseFileChange(It.IsAny<string>(), It.IsAny<uint>(), It.IsAny<IVsFileChangeEvents>(), out cookie))
                 .Returns(VSConstants.S_OK)
                 .Verifiable();
-            var tracker = new DefaultFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
+            var tracker = new VisualStudioFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
 
             // Act
             tracker.StartListening();
@@ -44,7 +43,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
                 .Setup(f => f.AdviseFileChange(It.IsAny<string>(), It.IsAny<uint>(), It.IsAny<IVsFileChangeEvents>(), out cookie))
                 .Returns(VSConstants.S_OK)
                 .Callback(() => callCount++);
-            var tracker = new DefaultFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
+            var tracker = new VisualStudioFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
             tracker.StartListening();
 
             // Act
@@ -68,7 +67,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
                 .Setup(f => f.UnadviseFileChange(cookie))
                 .Returns(VSConstants.S_OK)
                 .Verifiable();
-            var tracker = new DefaultFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
+            var tracker = new VisualStudioFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
             tracker.StartListening(); // Start listening for changes.
 
             // Act
@@ -87,7 +86,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
             fileChangeService
                 .Setup(f => f.UnadviseFileChange(cookie))
                 .Throws(new InvalidOperationException());
-            var tracker = new DefaultFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
+            var tracker = new VisualStudioFileChangeTracker("C:/_ViewImports.cshtml", Dispatcher, ErrorReporter, fileChangeService.Object);
 
             // Act & Assert
             tracker.StopListening();
@@ -107,7 +106,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
             fileChangeService
                 .Setup(f => f.AdviseFileChange(It.IsAny<string>(), It.IsAny<uint>(), It.IsAny<IVsFileChangeEvents>(), out cookie))
                 .Returns(VSConstants.S_OK);
-            var tracker = new DefaultFileChangeTracker(filePath, Dispatcher, ErrorReporter, fileChangeService.Object);
+            var tracker = new VisualStudioFileChangeTracker(filePath, Dispatcher, ErrorReporter, fileChangeService.Object);
 
             var called = false;
             tracker.Changed += (sender, args) =>

test/Microsoft.VisualStudio.Mac.LanguageServices.Razor.Test/Documents/VisualStudioMacFileChangeTrackerTest.cs

@@ -1,16 +1,12 @@
 // 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 Microsoft.CodeAnalysis.Razor;
-using Microsoft.VisualStudio.Editor.Razor;
-using MonoDevelop.Core;
-using Moq;
 using Xunit;
 
-namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
+namespace Microsoft.VisualStudio.Editor.Razor.Documents
 {
-    public class DefaultFileChangeTrackerTest : ForegroundDispatcherTestBase
+    public class VisualStudioMacFileChangeTrackerTest : ForegroundDispatcherTestBase
     {
         [ForegroundFact]
         public void StartListening_AdvisesForFileChange()
@@ -69,7 +65,7 @@ namespace Microsoft.VisualStudio.Mac.LanguageServices.Razor
             Assert.Equal(0, tracker.DetachFromFileServiceEventsCount);
         }
 
-        private class TestFileChangeTracker : DefaultFileChangeTracker
+        private class TestFileChangeTracker : VisualStudioMacFileChangeTracker
         {
             public TestFileChangeTracker(
                 string filePath,