CLI Hot reload Blazor wasm just doesn't work.

[ziaulhasanhamim]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

There were many issues about dotnet watch not working with blazor wasm. #38561, #36723, #40091 etc. It was mentioned there that the issue is fixed in .net 6.0.2. But it's not. The issue is there still. Furthermore, there are no responses now on those issues when it was informed that in .net6.0.2 it's not working. Very disappointing behavior.

dotnet watch --verbose logs

watch : Project supports hot reload and was configured to run with the default run-command. Watching with hot-reload
watch : Hot reload enabled. For a list of supported edits, see https://aka.ms/dotnet/hot-reload. Press "Ctrl + R" to restart.
watch : Building...
watch : Started 'C:\Program Files\dotnet\dotnet.exe' '' with process id 9496
  Determining projects to restore...
  Restored C:\Users\ziaul\Sources\BlazorWasmApp\BlazorWasmApp.csproj (in 1.39 sec).
  BlazorWasmApp -> C:\Users\ziaul\Sources\BlazorWasmApp\bin\Debug\net6.0\BlazorWasmApp.dll
  BlazorWasmApp (Blazor output) -> C:\Users\ziaul\Sources\BlazorWasmApp\bin\Debug\net6.0\wwwroot
watch : Process id 9496 ran for 27116ms
watch : Running MSBuild target 'GenerateWatchList' on 'C:\Users\ziaul\Sources\BlazorWasmApp\BlazorWasmApp.csproj'
watch : Started 'C:\Program Files\dotnet\dotnet.exe' '' with process id 9176
watch : Process id 9176 ran for 3657ms
watch : Watching 28 file(s) for changes
watch : dotnet-watch is configured to launch a browser on ASP.NET Core application startup.
watch : Configuring the app to use browser-refresh middleware.
watch : Refresh server running at wss://localhost:58192,ws://localhost:58193.
watch : HotReloadProfile: BlazorWebAssembly.
watch : Waiting for a browser to connect
watch : Started 'dotnet' '"C:\Users\ziaul\.nuget\packages\microsoft.aspnetcore.components.webassembly.devserver\6.0.2\build\../tools/blazor-devserver.dll" --applicationpath "C:\Users\ziaul\Sources\BlazorWasmApp\bin\Debug\net6.0\BlazorWasmApp.dll"' with process id 8976
watch : Running dotnet with the following arguments: run
watch : Started
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: https://localhost:7020
watch : Launching browser.
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://localhost:5152
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: C:\Users\ziaul\Sources\BlazorWasmApp
watch : Hot reload capabilities: .
watch : File changed: C:\Users\ziaul\Sources\BlazorWasmApp\Pages\Index.razor.
watch : No deltas modified. Applying changes to clear diagnostics.
watch : Received 1 from browser in [Count: 1, MessageType: Binary, EndOfMessage: True].
watch : No hot reload changes to apply.
watch : Hot reload change handled in 6599.4355ms.

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

6.0.200

Anything else?

No response

[javiercn]

@ziaulhasanhamim thanks for contacting us.

Could you provide a minimal repro project as a public github repository with detailed steps on how to trigger the issue so that we can make progress investigating?

Hi @ziaulhasanhamim. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[ziaulhasanhamim]

Could you provide a minimal repro project as a public github repository with detailed steps on how to trigger the issue so that we can make progress investigating?

dotnet new blazorwasm
then dotnet watch --verbose
you can see there watch : Hot reload capabilities: .
So there are no capabilities for hot reload.
Also sometimes it shows watch : Hot reload capabilities: Baseline
Then it works well

Thanks for contacting us.

We're moving this issue to the .NET 7 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[danroth27]

you can see there watch : Hot reload capabilities: .

@ziaulhasanhamim How often does this happen for you? I tried these steps several times, but I always ended up with Baseline and hot reload worked fine. Have you noticed anything that might be causing the capabilities to not get identified correctly?

[davidivkovic]

Not sure this is the right place, but figured it would be better than opening a new issue.
A similar problem occurs when running dotnet watch for a webapi inside a docker container on wsl2.
Works fine on the host Windows machine, but not inside the container.
Dotnet version 6.0.201

info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://[::]:80
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: /src/
watch : Hot reload capabilities: Baseline AddMethodToExistingType AddStaticFieldToExistingType AddInstanceFieldToExistingType NewTypeDefinition ChangeCustomAttributes UpdateParameters.
watch : File changed: /src/Controllers/WeatherForecastController.cs.
watch : No deltas modified. Applying changes to clear diagnostics.
watch : No hot reload changes to apply.
watch : Hot reload change handled in 25385.07ms.