The generated TypeInference class does not have access to _Imports.razor usings

[Tragetaschen]

Describe the bug:
When working with generic components and type inference, the TypeInference class is not generated in a context where _Imports.razor usings are available. I'm hitting this when a where clause needs to be repeated on that class.

Version used:
VS2022 17.0.1
SDK 6.0.100, Microsoft.AspNetCore.App 6.0.0

To reproduce:
Run dotnet build in https://github.com/Tragetaschen/blazor-type-inference-class-usings-issue

Expected behavior:
None of the files in the project show any errors in VS, so I expect the build to succeed.

Actual behavior:

Building produces the error

…\Microsoft.NET.Sdk.Razor.SourceGenerators\Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator\App_razor.g.cs(60,23): error CS0246: The type or namespace name 'MyModel' could not be found (are you missing a using directive or an assembly reference?) […\repro.csproj]

Additional context:
In the App_razor.g.cs, there is a TypeInference class that does not have any usings within its namespace:

namespace __Blazor.repro.App
{
    #line hidden
    internal static class TypeInference
    {
        public static void CreateGeneric_0<T>(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder, int seq, int __seq0, global::repro.Services.IService<T> __arg0, int __seq1, global::Microsoft.AspNetCore.Components.RenderFragment<T> __arg1)
            where T : MyModel
        {
        __builder.OpenComponent<global::repro.Generic<T>>(seq);
        __builder.AddAttribute(__seq0, "Service", __arg0);
        __builder.AddAttribute(__seq1, "R", __arg1);
        __builder.CloseComponent();
        }
    }
}

so the MyModel type in the where clause is not found.

[Tragetaschen]

The source generator will always just emit the MyModel type name in the where clause. I tried fully qualifying it in the generic component, but that didn't change it in the TypeInference class.

As a workaround, I have moved the using from _Imports.razor to a global using.

[Tragetaschen]

On a seemingly related note: A class generic constraint results in a syntax error in the TypeInference class.

I have added a commit to the reproduction repository showing this as well.

namespace __Blazor.repro.App
{
    #line hidden
    internal static class TypeInference
    {
        public static void CreateGeneric_0<T1, T2>(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder, int seq, int __seq0, global::repro.Services.IService<T1, T2> __arg0, int __seq1, global::Microsoft.AspNetCore.Components.RenderFragment<T1> __arg1)
            where T1 : MyModel
            where T2 : , class
        {
        __builder.OpenComponent<global::repro.Generic<T1, T2>>(seq);
        __builder.AddAttribute(__seq0, "Service", __arg0);
        __builder.AddAttribute(__seq1, "R", __arg1);
        __builder.CloseComponent();
        }
    }
}

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.

[jon001]

I don't have anything more than @Tragetaschen but since the msfbot or its handlers are assessing "community involvement" I thought I'd add my case to the list.

I'm using VS2022 v17.2.0 and the project in question is .NET6.0

I have a control named EntityView.razor which has markup including a second control named AddItemMenu.razor. This second control declares a typeparam as follows (I added the full qualification of IItemParent in a failed attempt to fix the compilation error).

@typeparam TParent where TParent: BlazorApp.Shared.Interfaces.Items.IItemParent

The generated code for the first component has this TypeInference class with the unqualified and unresolved IItemParent reference in the 'where' constraint:

namespace __Blazor.BlazorApp.Client.Components.Entities.EntityView
{
    #line hidden
    internal static class TypeInference
    {
        public static void CreateAddItemMenu_0<TParent>(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder, int seq, int __seq0, TParent __arg0)
            where TParent : IItemParent
        {

And this is the error in VS (linking to the generated file, which doesn't open when double-clicked - I had to find it manually in obj\Debug\net6.0\generated\Microsoft.NET.Sdk.Razor.SourceGenerators\Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator).

[Tragetaschen]

@chsienki Something bad happened. Besides this transfered issue with all the history, #7456, #7463, #7472, and #7477 were also created, but without any history.
This happened for three more of my issues as well