aspnetcore-browser-refresh injection doesn't respect path prefix

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Describe the bug

aspnetcore-browser-refresh.js Is not served on the same path prefix as supplied to UseBlazorFrameworkFiles.

Expected Behavior

If I call UseBlazorFrameworkFiles("/app") I expect this file to be served from /app/_framework/aspnetcore-browser-refresh.js like the other _framework files.

Steps To Reproduce

Create a stock Blazor app from template:

dotnet new blazor -int Server -o PathPrefix

Move Blazor setup in Program.cs into a middleware branch:

app.Map("/app", blazor => {
    blazor.UseRouting();
    blazor.UseAntiforgery();
    blazor.UseStaticFiles();
    blazor.UseBlazorFrameworkFiles("/app");
    blazor.UseEndpoints(e => e.MapRazorComponents<App>().AddInteractiveServerRenderMode());

});

Update App.razor <base href="/app/"/>

Load application and observe that aspnetcore-browser-refresh.js is not served on the supplied path prefix.

Exceptions (if any)

No response

.NET Version

8.0.1

Anything else?

No response

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 9 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.

[koureasstavros]

Situation is the same for Blazor WebAssembly Hosted with ASP.NET.

The framework file for hot reload (aspnetcore-browser-refresh.js) does not respect UseBlazorFrameworkFiles("/app") and it is placed into the root folder instead the subpath.

In addition some NUGET packages like Blazored.Modal which are using the css isolation and are importing bundle css (Blazored.Modal.bundle.scp.css) into the main css ({ASSEMBLY_NAME}.Client.styles.css) are still placing the css into root folder (_content/Blazored.Modal/) instead on subpath (subpath/_content/Blazored.Modal/) and refference is having a relative level up. See the issue here: Blazored/Modal#593

In addition there is issue with webassembly.js but in my case I managed to solve it by calling two times the app.UseStaticFiles in Server side one time without subpath and another time with the subpath #51929