make sure we only create OB when VS is running in IDE mode. all comma…

src/VisualStudio/CSharp/Impl/CSharpPackage.cs

@@ -85,8 +85,6 @@ protected override async Task InitializeAsync(CancellationToken cancellationToke
                     await JoinableTaskFactory.SwitchToMainThreadAsync(ct);
                     return new TempPECompilerService(this.Workspace.Services.GetService<IMetadataService>());
                 });
-
-                await RegisterObjectBrowserLibraryManagerAsync(cancellationToken).ConfigureAwait(true);
             }
             catch (Exception e) when (FatalError.ReportUnlessCanceled(e))
             {
@@ -98,17 +96,7 @@ protected override VisualStudioWorkspaceImpl CreateWorkspace()
             return this.ComponentModel.GetService<VisualStudioWorkspaceImpl>();
         }
 
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                JoinableTaskFactory.Run(() => UnregisterObjectBrowserLibraryManagerAsync(CancellationToken.None));
-            }
-
-            base.Dispose(disposing);
-        }
-
-        private async Task RegisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
+        protected override async Task RegisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
         {
             await JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
 
@@ -123,7 +111,7 @@ private async Task RegisterObjectBrowserLibraryManagerAsync(CancellationToken ca
             }
         }
 
-        private async Task UnregisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
+        protected override async Task UnregisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
         {
             await JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
 

src/VisualStudio/Core/Def/Implementation/LanguageService/AbstractPackage`2.cs

@@ -90,6 +90,10 @@ protected override async Task InitializeAsync(CancellationToken cancellationToke
 
                 // start remote host
                 EnableRemoteHostClientService();
+
+                // not every derived package support object browser and for those languages
+                // this is a no op
+                await RegisterObjectBrowserLibraryManagerAsync(cancellationToken).ConfigureAwait(true);
             }
 
             LoadComponentsInUIContextOnceSolutionFullyLoadedAsync(cancellationToken).Forget();
@@ -147,12 +151,17 @@ protected override void Dispose(bool disposing)
                     _miscellaneousFilesWorkspace.StopSolutionCrawler();
                 }
 
-                if (ThreadHelper.JoinableTaskFactory.Run(() => IsInIdeModeAsync(this.Workspace, CancellationToken.None)))
+                ThreadHelper.JoinableTaskFactory.Run(async () =>
                 {
-                    this.Workspace.StopSolutionCrawler();
+                    if (await IsInIdeModeAsync(this.Workspace, CancellationToken.None).ConfigureAwait(true))
+                    {
+                        this.Workspace.StopSolutionCrawler();
 
-                    DisableRemoteHostClientService();
-                }
+                        DisableRemoteHostClientService();
+
+                        await UnregisterObjectBrowserLibraryManagerAsync(CancellationToken.None).ConfigureAwait(true);
+                    }
+                });
 
                 // If we've created the language service then tell it it's time to clean itself up now.
                 if (_languageService != null)
@@ -167,6 +176,20 @@ protected override void Dispose(bool disposing)
 
         protected abstract string RoslynLanguageName { get; }
 
+        protected virtual Task RegisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
+        {
+            // it is virtual rather than abstract to not break other languages which derived from our
+            // base package implementations
+            return Task.CompletedTask;
+        }
+
+        protected virtual Task UnregisterObjectBrowserLibraryManagerAsync(CancellationToken cancellationToken)
+        {
+            // it is virtual rather than abstract to not break other languages which derived from our
+            // base package implementations
+            return Task.CompletedTask;
+        }
+
         private async Task<bool> IsInIdeModeAsync(Workspace workspace, CancellationToken cancellationToken)
         {
             return workspace != null && !await IsInCommandLineModeAsync(cancellationToken).ConfigureAwait(true);

src/VisualStudio/IntegrationTest/IntegrationTests/CSharp/CSharpBuild.cs

@@ -46,7 +46,7 @@ static void Main(string[] args)
             // TODO: Validate build works as expected
         }
 
-        [WpfFact(Skip = "https://github.com/dotnet/roslyn/issues/18204"), Trait(Traits.Feature, Traits.Features.Build)]
+        [WpfFact, Trait(Traits.Feature, Traits.Features.Build)]
         public void BuildWithCommandLine()
         {
             VisualStudio.SolutionExplorer.SaveAll();

src/VisualStudio/VisualBasic/Impl/LanguageService/VisualBasicPackage.vb

@@ -97,21 +97,11 @@ Namespace Microsoft.VisualStudio.LanguageServices.VisualBasic
                         Await JoinableTaskFactory.SwitchToMainThreadAsync(ct)
                         Return New TempPECompilerFactory(workspace)
                     End Function)
-
-                Await RegisterObjectBrowserLibraryManagerAsync(cancellationToken).ConfigureAwait(True)
             Catch ex As Exception When FatalError.ReportUnlessCanceled(ex)
             End Try
         End Function
 
-        Protected Overrides Sub Dispose(disposing As Boolean)
-            If disposing Then
-                JoinableTaskFactory.Run(Function() UnregisterObjectBrowserLibraryManagerAsync(CancellationToken.None))
-            End If
-
-            MyBase.Dispose(disposing)
-        End Sub
-
-        Private Async Function RegisterObjectBrowserLibraryManagerAsync(cancellationToken As CancellationToken) As Task
+        Protected Overrides Async Function RegisterObjectBrowserLibraryManagerAsync(cancellationToken As CancellationToken) As Task
             Await JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken)
 
             Dim objectManager = TryCast(Await GetServiceAsync(GetType(SVsObjectManager)).ConfigureAwait(True), IVsObjectManager2)
@@ -124,7 +114,7 @@ Namespace Microsoft.VisualStudio.LanguageServices.VisualBasic
             End If
         End Function
 
-        Private Async Function UnregisterObjectBrowserLibraryManagerAsync(cancellationToken As CancellationToken) As Task
+        Protected Overrides Async Function UnregisterObjectBrowserLibraryManagerAsync(cancellationToken As CancellationToken) As Task
             Await JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken)
 
             If _libraryManagerCookie <> 0 Then