Debuggin Blazor Webassembly project of Visual Studio 2022 does not work correctly with a Visual Basic Library .NET 6 or .NET Standard Project containing Async method.

[ivoryguard]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Debugging function of Blazor Webassembly project (like watching variable values/evaluating in Immediate window) of Visual Studio 2022 does not work correctly with referencing a Visual Basic Library .NET 6 or .NET Standard Project containing Async method.

All debuging functions except breaking point in async methods in Visual Basic Library .NET 6 or .NET Standard Project, which is referred to C# Blazor WebAssembly project, do not work with the following message in Locals window;

Error processing variables: TypeError: Cannot read properties of undefined (reading 'subtype')
    at Object.isArray (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\objectPreview\index.js:58:19)
    at I.createVariableByType (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:114:27)
    at Q.getChildren (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:659:45)
    at process.children (node:internal/process/task_queues:96:5)
    at n._a [as getVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:783:15)
    at j.result [as _onVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\debugAdapter.js:269:30)
    at t.default._onMessage (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\dap\connection.js:145:27)

However, debugging functions in other non-async methods in Visual Basic Library .NET 6 or .NET Standard Project work correctly.

I updated Visual Studio 2022 up to the latest version (17.3.6) and updated all nuget packages.
I also deleted obj/bin folders and did clean->rebuilding, but it did not disappeared.

I am attaching Locals Window screen shots for calling non-async method and asycn method.

The following is for none-async method;

The following is for async method;

The issue occurs for Visual Basic .NET Standard Library Project as well as Visual Basic .NET 6 library project.
It makes hard to develop Blazor WebAssembly apps with existing Visual Basic .NET Standard/.NET6 Library projects which utilize async keyword.

Expected Behavior

All debugging functions - watching local variables and evaluating Immediate Window - must work with async method in referred Visual Basic Library Projects.

Steps To Reproduce

1. Open Visual Studio 2022

2. Create a Blazor WebAssembly Project (C# .NET 6) without ASP.NET Core Hosting

3. Add a Visual Basic Library Project (.NET 6 or .NET Standard 2.0/2.1)

4. Add project reference of Visual Basic Library Project to Blazor WebAssembly Project

5. Add a Class to Visual Basic Library Project as the followings;

Public Class TestService
    Public Function Test(data As String) As String
        Return data
    End Function

    Public Async Function TestAsync(data As String) As Task(Of String)
        Await Task.Delay(10)
        Return data
    End Function

End Class

6. Modify Program.cs of Blazor WebAssembly Project as the followings;

using BlazorApp1;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components.WebAssembly.Hosting;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

//To call VB Library Project methods
var testService = new ClassLibrary1.TestService();
var result = testService.Test("1234");
var resultAsync = await testService.TestAsync("1234");

await builder.Build().RunAsync();

7. Add a break point at the line of 'var result = testService.Test("1234");'

8. Start Blazor WebAssembly Project and debug into testService.Test and await testService.TestAsync.

9. You can see "data" variable value in Auto/Locals window in TestService.Test method.

10. You cannot see "data" variable value in Auto/Locals window in TestService.TestAsync method.

Exceptions (if any)

		Error processing variables: TypeError: Cannot read properties of undefined (reading 'subtype')
at Object.isArray (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\objectPreview\index.js:58:19)
at I.createVariableByType (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:114:27)
at Q.getChildren (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:659:45)
at process.children (node:internal/process/task_queues:96:5)
at n._a [as getVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:783:15)
at j.result [as _onVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\debugAdapter.js:269:30)
at t.default._onMessage (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\dap\connection.js:145:27)	

.NET Version

6.0.402

Anything else?

Test Envrionment:
Windows 10
Visual Studio 2022
.NET 6 Blazor WebAssembly Project Template

C:\Program Files\Microsoft Visual Studio\2022\Enterprise>dotnet --info
.NET SDK:
 Version:   6.0.402
 Commit:    6862418796

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19043
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.402\

global.json file:
  Not found

Host:
  Version:      6.0.10
  Architecture: x64
  Commit:       5a400c212a

.NET SDKs installed:
  5.0.214 [C:\Program Files\dotnet\sdk]
  5.0.303 [C:\Program Files\dotnet\sdk]
  5.0.408 [C:\Program Files\dotnet\sdk]
  6.0.402 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

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See info in area-owners.md if you want to be subscribed.

Issue Details

---

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Debugging function of Blazor Webassembly project (like watching variable values/evaluating in Immediate window) of Visual Studio 2022 does not work correctly with referencing a Visual Basic Library .NET 6 or .NET Standard Project containing Async method.

All debuging functions except breaking point in async methods in Visual Basic Library .NET 6 or .NET Standard Project, which is referred to C# Blazor WebAssembly project, do not work with the following message in Locals window;

Error processing variables: TypeError: Cannot read properties of undefined (reading 'subtype')
    at Object.isArray (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\objectPreview\index.js:58:19)
    at I.createVariableByType (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:114:27)
    at Q.getChildren (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:659:45)
    at process.children (node:internal/process/task_queues:96:5)
    at n._a [as getVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:783:15)
    at j.result [as _onVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\debugAdapter.js:269:30)
    at t.default._onMessage (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\dap\connection.js:145:27)

However, debugging functions in other non-async methods in Visual Basic Library .NET 6 or .NET Standard Project work correctly.

I updated Visual Studio 2022 up to the latest version (17.3.6) and updated all nuget packages.
I also deleted obj/bin folders and did clean->rebuilding, but it did not disappeared.

I am attaching Locals Window screen shots for calling non-async method and asycn method.

The following is for none-async method;

The following is for async method;

The issue occurs for Visual Basic .NET Standard Library Project as well as Visual Basic .NET 6 library project.
It makes hard to develop Blazor WebAssembly apps with existing Visual Basic .NET Standard/.NET6 Library projects which utilize async keyword.

Expected Behavior

All debugging functions - watching local variables and evaluating Immediate Window - must work with async method in referred Visual Basic Library Projects.

Steps To Reproduce

1. Open Visual Studio 2022

2. Create a Blazor WebAssembly Project (C# .NET 6) without ASP.NET Core Hosting

3. Add a Visual Basic Library Project (.NET 6 or .NET Standard 2.0/2.1)

4. Add project reference of Visual Basic Library Project to Blazor WebAssembly Project

5. Add a Class to Visual Basic Library Project as the followings;

Public Class TestService
    Public Function Test(data As String) As String
        Return data
    End Function

    Public Async Function TestAsync(data As String) As Task(Of String)
        Await Task.Delay(10)
        Return data
    End Function

End Class

6. Modify Program.cs of Blazor WebAssembly Project as the followings;

using BlazorApp1;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components.WebAssembly.Hosting;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

//To call VB Library Project methods
var testService = new ClassLibrary1.TestService();
var result = testService.Test("1234");
var resultAsync = await testService.TestAsync("1234");

await builder.Build().RunAsync();

7. Add a break point at the line of 'var result = testService.Test("1234");'

8. Start Blazor WebAssembly Project and debug into testService.Test and await testService.TestAsync.

9. You can see "data" variable value in Auto/Locals window in TestService.Test method.

10. You cannot see "data" variable value in Auto/Locals window in TestService.TestAsync method.

Exceptions (if any)

		Error processing variables: TypeError: Cannot read properties of undefined (reading 'subtype')
at Object.isArray (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\objectPreview\index.js:58:19)
at I.createVariableByType (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:114:27)
at Q.getChildren (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:659:45)
at process.children (node:internal/process/task_queues:96:5)
at n._a [as getVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\variableStore.js:783:15)
at j.result [as _onVariables] (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\adapter\debugAdapter.js:269:30)
at t.default._onMessage (c:\program files\microsoft visual studio\2022\enterprise\common7\ide\commonextensions\microsoft\jsdiagnostics\debugger\debugAdapter\out\src\dap\connection.js:145:27)	

.NET Version

6.0.402

Anything else?

Test Envrionment:
Windows 10
Visual Studio 2022
.NET 6 Blazor WebAssembly Project Template

C:\Program Files\Microsoft Visual Studio\2022\Enterprise>dotnet --info
.NET SDK:
 Version:   6.0.402
 Commit:    6862418796

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19043
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.402\

global.json file:
  Not found

Host:
  Version:      6.0.10
  Architecture: x64
  Commit:       5a400c212a

.NET SDKs installed:
  5.0.214 [C:\Program Files\dotnet\sdk]
  5.0.303 [C:\Program Files\dotnet\sdk]
  5.0.408 [C:\Program Files\dotnet\sdk]
  6.0.402 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.30 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Author:	ivoryguard
Assignees:	-
Labels:	area-Debugger-mono
Milestone:	-

[ivoryguard]

Is there any solution or workaround for current .NET 6 and Visual Studio 2022? Do I have nothing but to convert existing VB.NET Library codes to C#?

[thaystg]

[thaystg]

I think this is fixed, or I'm missing something to reproduce.
@ivoryguard can you test it again using the newest Visual Studio?