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MACIOS ELIMINATES TEST FLAKINESS WITH IN-PROC HTTP SERVER, EFCORE FIXES QUERY PERFORMANCE AND UPDATE BUGS
By RepoJournal · Filed · About .NET
The biggest wins across .NET today come from killing external dependencies in test infrastructure and fixing two critical EF Core bugs that break real-world scenarios.
The macios team shipped a heavyweight infrastructure change: replacing all httpbin.org dependencies in tests with a lightweight in-proc HTTP server [1], eliminating the network flakiness that's plagued test reliability. This is the kind of unsexy work that pays dividends for months. In the same repo, they're building an 'assembly-preparer' tool [2] to offload custom linker work to a dedicated build step, gated behind `PrepareAssemblies=true`. Meanwhile, EF Core landed two critical fixes: `ExecuteUpdate` now returns correct row counts instead of -1 on open connections by flipping NOCOUNT OFF [4], and Dictionary<string,object> properties with explicit column types (like `jsonb`) are now correctly recognized instead of throwing shared-type entity errors [5]. The latter fix required promoting several pubternal types to public, which is a sign the issue was fundamental. EF Core also added support for runtime constants in precompiled queries [3], moving expensive operations to compile time. The SDK continues its MSTest migration sprint across template engine and command-line test projects [6], [7], [8], while aspnetcore addressed a critical gap: WebViewRenderer now properly handles all Blazor render modes as no-ops instead of throwing `NotSupportedException` [10]. The aspnetcore quarantine workflow was also tightened to distinguish between real regressions and genuinely flaky tests [9], preventing false auto-quarantines that mask actual failures.
Action items
- → Pull the ExecuteUpdate fix [ref:7] if you're using bulk update operations on open connections dotnet/efcore [plan]
- → Test your Dictionary<string,object> property mappings with explicit column types after upgrading EF Core dotnet/efcore [monitor]
- → If you maintain xUnit test projects in SDK, watch for the MSTest migration pattern [ref:13], [ref:14], [ref:15] and adapt accordingly dotnet/sdk [plan]
- → Update Blazor Hybrid apps (MAUI) to confirm WebViewRenderer render modes work after the fix [ref:20] dotnet/aspnetcore [monitor]
References
- [1] [tests] Replace httpbin.org with an in-proc HTTP server to improve reliability. ↗ dotnet/macios
- [2] [assembly-preparer] Create a new tool to replace pre-mark custom linker steps. ↗ dotnet/macios
- [3] Allow runtime constants in precompiled queries ↗ dotnet/efcore
- [4] Fix ExecuteUpdate returning -1 on open connections by setting NOCOUNT OFF ↗ dotnet/efcore
- [5] Honor explicit store type when discovering Dictionary<string,object> ↗ dotnet/efcore
- [6] Migrate Microsoft.TemplateEngine.TemplateLocalizer.Core.UnitTests to MSTest.Sdk on MTP ↗ dotnet/sdk
- [7] Migrate Microsoft.TemplateEngine.Utils.UnitTests to MSTest.Sdk on MTP ↗ dotnet/sdk
- [8] Migrate System.CommandLine.StaticCompletions.Tests to MSTest.Sdk ↗ dotnet/sdk
- [9] Quarantine only flaky tests, not consistent regressions ↗ dotnet/aspnetcore
- [10] Override ResolveComponentForRenderMode in WebViewRenderer to treat all render modes as no-ops ↗ dotnet/aspnetcore
FAQ
- What changed in .NET on June 18, 2026?
- The biggest wins across .NET today come from killing external dependencies in test infrastructure and fixing two critical EF Core bugs that break real-world scenarios.
- What should .NET teams do about it?
- Pull the ExecuteUpdate fix [ref:7] if you're using bulk update operations on open connections • Test your Dictionary<string,object> property mappings with explicit column types after upgrading EF Core • If you maintain xUnit test projects in SDK, watch for the MSTest migration pattern [ref:13], [ref:14], [ref:15] and adapt accordingly
- Which .NET repositories shipped on June 18, 2026?
- dotnet/macios, dotnet/efcore, dotnet/sdk, dotnet/aspnetcore