VisualStudioWorkspace - too many WorkspaceChanged by solution opening

[AlexNek]

Version Used:
Microsoft Visual Studio Community 2019 Preview
Version 16.8.0 Preview 3.2

Steps to Reproduce:

1. Create VS Package over Wizard
2. Add a command
3. Add a log code

protected override async Task InitializeAsync(CancellationToken cancellationToken, IProgress<ServiceProgressData> progress)
        {
            await this.JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
            IComponentModel componentModel = (IComponentModel)GetService(typeof(SComponentModel));

            _workspace = componentModel.GetService<VisualStudioWorkspace>();
            _workspace.WorkspaceChanged += Workspace_WorkspaceChanged;
            await CommandTest.InitializeAsync(this);
        }

        private void Workspace_WorkspaceChanged(object sender, Microsoft.CodeAnalysis.WorkspaceChangeEventArgs e)
        {
            DocumentId documentId = e.DocumentId;
            WorkspaceChangeKind workspaceChangeKind = e.Kind;
            ProjectId projectId = e.ProjectId;
            int currWorkspaceVersion = (int)_workspace.CurrentSolution.GetPropertyValue("WorkspaceVersion");

            if (workspaceChangeKind == WorkspaceChangeKind.SolutionAdded
                || workspaceChangeKind == WorkspaceChangeKind.SolutionChanged
                || workspaceChangeKind == WorkspaceChangeKind.SolutionRemoved)
            {
                int oldWorkspaceVersion = (int)e.OldSolution.GetPropertyValue("WorkspaceVersion");
                int newWorkspaceVersion = (int)e.NewSolution.GetPropertyValue("WorkspaceVersion");
                
                Trace.WriteLine($"--- workspace changed kind: {workspaceChangeKind},  old solution:{e.OldSolution.FilePath},  new solution: {e.NewSolution.FilePath}");
                Trace.WriteLine($"--* curr vers:{currWorkspaceVersion}, new:{newWorkspaceVersion} old:{oldWorkspaceVersion}");
            }
            else
            {
                Project project = _workspace.CurrentSolution.GetProject(projectId);
                Document document = _workspace.CurrentSolution.GetDocument(documentId);
                int? projectWorkspaceVersion = (int?)project?.Solution.GetPropertyValue("WorkspaceVersion");
                int? documentWorkspaceVersion = (int?)document?.Project.Solution.GetPropertyValue("WorkspaceVersion");
                Trace.WriteLine($"--- workspace changed kind: {workspaceChangeKind},  documentId:{documentId},  projectId: {projectId}");
                Trace.WriteLine($"--* curr vers:{currWorkspaceVersion}, project:{projectWorkspaceVersion} document:{documentWorkspaceVersion}");
            }
        }

Expected Behavior:
I must receive only one "SolutionAdded" event with correct "WorkspaceVersion".

Actual Behavior:

--- workspace changed kind: SolutionAdded,  old solution:,  new solution: C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1.sln
--* curr vers:50, new:47 old:45
--- workspace changed kind: ProjectChanged,  documentId:,  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:53, project:53 document:
--- workspace changed kind: ProjectChanged,  documentId:,  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:53, project:53 document:
--- workspace changed kind: ProjectChanged,  documentId:,  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:54, project:54 document:
--- workspace changed kind: SolutionChanged,  old solution:C:\Users\userad\source\repos\ConsoleApp1\ConsoleApp1.sln,  new solution: C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1.sln
--* curr vers:54, new:51 old:50
--- workspace changed kind: ProjectChanged,  documentId:,  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:54, project:54 document:
--- workspace changed kind: DocumentChanged,  documentId:(DocumentId, #526d0aa3-5020-49c2-a631-d9de3079b2a8 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\Program.cs),  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\userad\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:54, project:54 document:54
--- workspace changed kind: ProjectChanged,  documentId:,  projectId: (ProjectId, #960fbaca-1726-44bd-8f6b-86557a8e52d1 - C:\Users\user\source\repos\ConsoleApp1\ConsoleApp1\ConsoleApp1.csproj (Debug;AnyCPU {032DF584-7DCE-4742-AE8E-0BBFD0750EAA}))
--* curr vers:54, project:54 document:

Note
I create the VS Package and have a lot of problems.
One of it - I can not trust WorkspaceChanged event, together with internal field "WorkspaceVersion".
In my opinion I must receive only one "SolutionAdded" event with correct "WorkspaceVersion".
But instead it I received the some sequence from DocumentChanged, ProjectChanged, SolutionChanged events with increased WorkspaceVersion.
I can not init my package after receiving SolutionAdded event (similar with DTE) and later I have the troubles with "workspace.TryApplyChanges" while "WorkspaceVersion" are different.

[CyrusNajmabadi]

In my opinion I must receive only one "SolutionAdded" event with correct "WorkspaceVersion".
But instead it I received the some sequence from DocumentChanged, ProjectChanged, SolutionChanged events with increased WorkspaceVersion.

Yes. this is by design. First we add the solution, then we add all the projects/documents to it, causing 'changing' notifications to be emitted.

[AlexNek]

Thanks for explanation, but how can I find load finishing or distinguish VS changes from my?

[CyrusNajmabadi]

there is no concept in roslyn. Roslyn has events here because the changes may happen forever (i.e. that's what happens when a user opens VS and then works in it continually). VS has some events you can try listening to. however, there is no guarantee of anything on the Roslyn side. For the VS side, you can use APIs like IVsOperationProgressStatusService to determine this. i.e.:

                var service = await _serviceProvider.GetServiceAsync<SVsOperationProgress, IVsOperationProgressStatusService>(throwOnFailure: false)
                                                    .WithCancellation(cancellationToken).ConfigureAwait(false);

                return service.GetStageStatusForSolutionLoad(CommonOperationProgressStageIds...);

[AlexNek]

Thanks a lot.
statusForSolutionLoad = service.GetStageStatusForSolutionLoad(CommonOperationProgressStageIds.Intellisense);
Only intellisense stage is supported currently. Parameter name: operationProgressStageId