Scoped CSS in netcoreapp3.1

[stefanloerwald]

Is scoped CSS supposed to be active in a project targetting netcoreapp3.1? I get build errors, because I have a file foo.razor.css without a file foo.razor.

To reproduce:

1. dotnet new blazorserver -f netcoreapp3.1
2. echo "" > foo.razor.css
3. dotnet build

error BLAZOR102: The scoped css file 'foo.razor.css' was defined but no associated razor component was found for it.

There's no build error for a class lib targetting netstandard2.1. Is this on purpose or should it only work net5.0 and following?

[javiercn]

Scoped CSS is a 5.0 feature and won't be coming to 3.1

[javiercn]

Unfortunately there is no way to convert discussions into issues, but I'm not sure what the bug here is, can you clarify?

[stefanloerwald]

Well given the above instructions, it looks like scoped CSS processing runs when the target framework is set to netcoreapp3.1, even though it should only do so on net5.0+.

[javiercn]

Yeah, this is a bug. The issue is here, you can disable manually if you need to <ScopedCssEnabled>false</ScopedCssEnabled>
https://github.com/dotnet/aspnetcore/blob/master/src/Razor/Microsoft.NET.Sdk.Razor/src/build/netstandard2.0/Sdk.Razor.CurrentVersion.targets#L76

[stefanloerwald]

Great that you already found the root cause. Thanks for the hard work!

[stefanloerwald]

I created an issue (#27768) for this, as it's a more appropriate place to track bugs than here.