.net8 UsePathBase fails to change the pathbase

[lymem]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

In attempting to upgrade my .net projects to .net 8, I've run in to a breaking issue with app.UsePathBase(). In .net 6 and .net 7, specifying app.UsePathBase("Path"); would change your url from https://www.somesite.com/ to https://www.somesite.com/Path. The use of this is important when hosting a number of seperate websites on the same domain behind a reverse proxy. Ref: https://www.geeksforgeeks.org/components-of-a-url/

Expected Behavior

After specifying:
string NewPath = "/blazor";
app.UsePathBase(NewPath);
My expectation is that the website, including when running locally, would appear as http/s/:domain/NewPath.

Steps To Reproduce

Using Visual Studio Community 2022 version 17.8.5, dotnet sdk 8.0.101 :

• Create a new project
• • Blazor Web App
• • framework: .net 8.0 long term support
• • Authentication type: none
• • Configure HTTPS: true
• • Interactive render mode: server
• • Interactivity location: Global
• • Include sample pages: true
• • do not use top-level statements: true
    Code changes:
• program.cs - replace lines 25-27 with:
  app.UsePathBase("/blazor/");
  app.UseStaticFiles();
  app.UseHttpsRedirection();
  app.UseRouting();
• App.razor - replace line 7 with:

Run the project using https.

Exceptions (if any)

No response

.NET Version

8.0.101

Anything else?

`dotnet --info
.NET SDK:
Version: 8.0.101
Commit: 6eceda187b
Workload version: 8.0.100-manifests.df7c29bf

Runtime Environment:
OS Name: Windows
OS Version: 10.0.19045
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\8.0.101\

.NET workloads installed:
Workload version: 8.0.100-manifests.df7c29bf
There are no installed workloads to display.

Host:
Version: 8.0.1
Architecture: x64
Commit: bf5e279d92

.NET SDKs installed:
8.0.101 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 7.0.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 7.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 7.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download`

[lymem]

Sample code: https://github.com/lymem/BlazorTemplateNet8

[lymem]

I have worked out how to properly host at a sub path. I updated the sample code in the above GitHub repo to illustrate what I did to do so. The key in this scenerio seems to be that the .UsePathBase path needs to end in a '/', and so does the .