Document How to Enable Hot Reloading Using dotnet run/watch

[RehanSaeed]

Is your feature request related to a problem? Please describe.

It is not clear how to enable hot reloading using dotnet run or dotnet watch from a launchSettings.json file. The .NET blog mention that we should add the "hotReloadProfile": "aspnetcore" setting like so:

"Kestrel": {
  "commandName": "Project",
  "dotnetRunMessages": true,
  "hotReloadProfile": "aspnetcore"
  "launchBrowser": true,
  "launchUrl": "weatherforecast",
  "applicationUrl": "http://localhost:5093",
  "environmentVariables": {
    "ASPNETCORE_ENVIRONMENT": "Development"
  }
},

However, I also came across this PR which removes this need:

• https://github.com/dotnet/aspnetcore/pull/32469/files

Then there is the question about how to enable the feature when using dotnet watch in a launchSettings.json file:

"Watch Kestrel (CTRL+F5)": {
  "commandName": "Executable",
  "executablePath": "dotnet",
  "workingDirectory": "$(ProjectDir)",
  "commandLineArgs": "watch",
  "environmentVariables": {
    "ASPNETCORE_ENVIRONMENT": "Development"
  }
},

It would also be nice to know if this affects IIS Express or WSL2

    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "graphql",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "WSL 2": {
      "commandName": "WSL2",
      "launchBrowser": true,
      "launchUrl": "http:////localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_URLS": "http://localhost:5000",
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "distributionName": ""
    },

Describe the solution you'd like

I'd like to know how to enable the feature for both dotnet run and dotnet watch from a launchSettings.json file and have this documented somewhere.

[taha-ghadirian]

Hello @RehanSaeed, There is still some problems with Dotnet hot reload.
If you have Dotnet 6 RC1 or higher (current version RC2), you can use (Dotnet watch --project .).
Dotnet watch command have some problems that need to be fixed as soon as it's possible. but for temporal ignoring errors, you should use --project PROJECTLOCATION flag.

NOTE: You don't need to edit launchSettings.json or any other settings if you are running on dotnet 6 preview6 or higher.

Wrong examples:
Dotnet watch
Dotnet watch run
Dotnet watch --project ./apps/client/ run

Correct examples:
Dotnet watch --project . (Dot means current location)
Dotnet watch --project ./apps/client

[mkArtakMSFT]

Thanks for contacting us.
Looks like @taha-ghadirian answered this already on how to achieve what you're looking for. Closing, as there are no more actions pending here.

[taha-ghadirian]

Hello @mkArtakMSFT, I think we should consider it as a bug, because normally we just need to run dotnet watch command without --project . flag when we are in the same directory of the project.

Also dotnet watch command will fail when system goes to sleep. So we should restart system (Not restarting dotnet watch) to fix this issue.

[chhinsras]

I use dotnet watch run or dotnet run inside Server project (Blazor Hosted). File changed detected but No hot reload change to apply , why?

I need to run Client project. but how can i run both Server and Client?

[taha-ghadirian]

I use dotnet watch run or dotnet run inside Server project (Blazor Hosted). File changed detected but No hot reload change to apply , why?

Actually it's a bug in dotnet watch command, please run this command in Server project and use --project . flag.
This solution will fix that issue.

[chhinsras]

I use dotnet watch run or dotnet run inside Server project (Blazor Hosted). File changed detected but No hot reload change to apply , why?

Actually it's a bug in dotnet watch command, please run this command in Server project and use --project . flag. This solution will fix that issue.

are you saying go to Server folder. then run dotnet watch --project ? will it run Client project as well?

I followed and NO client project wont have hot reload

[taha-ghadirian]

Hello @chhinsras, Yes!
Open Server project, run Dotnet watch --project . or dotnet watch --project .\ProjectName.csproj or dotnet watch --project ProjectName.csproj one of this commands should work.

[taha-ghadirian]

are you saying go to Server folder. then run dotnet watch --project ? will it run Client project as well?

I followed and NO client project wont have hot reload

Can you run it again with -v flag? Then copy all logs for us, thanks :)

[chhinsras]

are you saying go to Server folder. then run dotnet watch --project ? will it run Client project as well?
I followed and NO client project wont have hot reload

Can you run it again with -v flag? Then copy all logs for us, thanks :)

[taha-ghadirian]

are you saying go to Server folder. then run dotnet watch --project ? will it run Client project as well?

Look at last line, it says: Watch: Hot reload capabilities: . but it should say: Watch: Hot reload capabilities: BASELINE..

please use this comment then check if it's fixed or not: dotnet watch --project .\Server.csproj -v
If it wouldn't fix, try changing your default browser to a new chrome browser (without any extension installed).

[chhinsras]

are you saying go to Server folder. then run dotnet watch --project ? will it run Client project as well?

Look at last line, it says: Watch: Hot reload capabilities: . but it should say: Watch: Hot reload capabilities: BASELINE..

please use this comment then check if it's fixed or not: dotnet watch --project .\Server.csproj -v If it wouldn't fix, try changing your default browser to a new chrome browser (without any extension installed).

I followed your recommendation. still no luck. Its not updating the UI

[jhulbertpmn]

Same issue here.

info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
Request starting HTTP/2 POST https://localhost:5001/_framework/blazor-hotreload application/json 2
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 839.5826ms.

[chhinsras]

in any workaround

[ceeol]

Tried all the different suggestions, and this was really a struggle.
I did manage to get hot reload working by creating the small template project by using exactly --project .\Server.csproj, and getting Baseline.
No luck with another project though, just getting "watch : Hot reload capabilities: ." This was earlier created with .Net 5, and I discovered there were upgrades. Finally got it to work. It needs to be more user friendly than this, though.

[chhinsras]

@ceeol

Still no luck tho. Really disappointed. how simple thing like this can't be working.