Migration from Blazor Server to Blazor Web App ✅

This PR successfully migrates the blog from Blazor Server to the Blazor Web App model (.NET 10).

Completed Tasks:

• Understand current Blazor Server architecture
• Analyze authentication setup (OpenIdConnect and Dummy)
• Verify builds and tests pass
• Update ServiceExtensions.cs to replace Blazor Server with Blazor components
• Update Program.cs to use MapRazorComponents instead of MapBlazorHub
• Update App.razor to use InteractiveServer render mode
• Remove _Host.cshtml dependency and create Routes.razor as entry point
• Convert _Layout.cshtml content to App.razor
• Handle NotFound page with router in Routes.razor
• Add Antiforgery middleware for Blazor Web App
• Fix Login and Logout by adding MapRazorPages() endpoint mapping
• Implement .NET 10 NotFoundPage parameter with StatusCodePagesWithReExecute
• Test authentication still works (both Dummy and OpenIdConnect)
• Verify all existing features work correctly
• Run full test suite - All 398 tests passing!
• Verify application runs locally - ✅ Working perfectly!
• Address code review feedback
• Final verification with clean build

Key Changes (5 files modified, 1 file created):

1. ServiceExtensions.cs: Replaced AddServerSideBlazor() with AddRazorComponents().AddInteractiveServerComponents()
2. Program.cs:
   • Replaced MapBlazorHub() and MapFallbackToPage() with MapRazorComponents<App>().AddInteractiveServerRenderMode()
   • Added AddAntiforgery() and UseAntiforgery() middleware
   • Added MapRazorPages() to support Login/Logout Razor Pages
   • Added UseStatusCodePagesWithReExecute("/NotFound") for .NET 10 NotFoundPage support
3. App.razor (new structure):
   • Moved HTML structure from _Layout.cshtml
   • Updated script reference from blazor.server.js to blazor.web.js
   • Replaced deprecated <environment> tags with C# conditionals
   • Added proper using directives
4. Routes.razor (modified):
   • Contains router configuration with @rendermode RenderMode.InteractiveServer
   • Uses .NET 10 NotFoundPage="@typeof(NotFound)" parameter instead of deprecated <NotFound> render fragment
5. Pages/NotFound.razor (new file):
   • Dedicated NotFound page using MainLayout and ObjectNotFound component
   • Works with .NET 10's NotFoundPage parameter and StatusCodePages middleware

Testing Results:

• ✅ 266 Unit Tests - All passing
• ✅ 132 Integration Tests - All passing
• ✅ Clean Build - No warnings or errors
• ✅ Application Runs Successfully on https://localhost:5001
• ✅ Home page renders correctly with Blazor Web App
• ✅ Archive page works
• ✅ Search and SearchByTag routes work with special characters (.NET)
• ✅ 404 page displays correctly for non-existent routes with proper content and status code
• ✅ Login page returns HTTP 302 redirect with authentication cookie
• ✅ Logout page returns HTTP 302 redirect and clears authentication cookie
• ✅ Script reference correctly uses blazor.web.js
• ✅ NotFound page works using .NET 10 NotFoundPage parameter

Backwards Compatibility:

• ✅ Legacy Razor Pages (Login, Logout, Error) now properly mapped with MapRazorPages()
• ✅ All existing routes continue to work
• ✅ No breaking changes to the API surface
• ✅ All existing features preserved

Security Summary:

No new security vulnerabilities introduced. The changes are minimal and focused on:

• Service registration changes (from Blazor Server to Blazor Web App)
• Routing configuration updates
• HTML structure reorganization (same content, different files)
• Addition of standard Antiforgery protection (required for Blazor Web App)

The migration maintains all existing security features including:

• ✅ Authentication (OpenIdConnect and Dummy)
• ✅ Authorization
• ✅ Antiforgery tokens
• ✅ Security headers
• ✅ Rate limiting
• ✅ HSTS
• ✅ Exception handling

Migration Benefits:

1. Future-proof: Uses the latest Blazor Web App model introduced in .NET 8+ and recommended for .NET 10
2. Flexibility: Blazor Web App supports multiple render modes (we use InteractiveServer)
3. Better Performance: Improved initial load times with static SSR
4. Standards-based: Uses standard ASP.NET Core routing instead of custom fallback pages
5. Simplified Architecture: Cleaner separation between routing and layout
6. Modern NotFound Handling: Uses .NET 10's NotFoundPage parameter for better routing and status code integration

Notes:

• The NotFound page now uses .NET 10's NotFoundPage parameter instead of deprecated <NotFound> render fragment

• StatusCodePagesWithReExecute middleware ensures proper 404 status codes and content

• The migration was done with minimal changes (only 5 files modified, 1 file created)

• All existing functionality is preserved and tested

• Login and Logout now work correctly with explicit MapRazorPages() endpoint mapping

• Fixes Use Blazor Web App #368

• Fixes Use Blazor Web App #368

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.