Tag: csharp

ModelContextProtocol 2.0.0 flipped HTTP transport to stateless by default, which is the one change that can drop every client still speaking 2025-11-25. HttpServerSessionMode.StatefulForInitializeClients in 2.2.0 serves both revisions on one endpoint. Here is the ordered upgrade, the ten breaking changes that matter, and the discover-probe bug that only a 2.1.0 client fixes.

A step-by-step migration from xunit 2.9.3 to xunit.v3 4.0.0: package swaps, the OutputType Exe change, IAsyncLifetime returning ValueTask, the Xunit.Abstractions removal, and the CI filter syntax that silently stops matching.

Eliding async/await in a repository passthrough saves about 6 ns and 72 bytes, and costs you a stack frame, try/catch semantics, and safe disposal. Keep return await unless the method is a pure passthrough on a measured hot path.

CA1070 fires on virtual field-like events. Drop the virtual, keep the event non-virtual, and let derived classes override a protected virtual OnXxx raiser instead.

MCP9005 is advisory, but MCP9004 crashes at startup and stateless mode makes SampleAsync throw. Here is what each diagnostic means and how to fix it properly.

Move every package version out of your csproj files into one Directory.Packages.props. Covers a generator script that reconciles conflicting versions with real semver ordering, the before/after dependency-graph diff that proves what moved, NU1008/NU1010/NU1013/NU1507, transitive pinning, GlobalPackageReference, VersionOverride, and why a nested Directory.Packages.props silently shadows the root one.

Blazor has no syntax for a variable tag name, and DynamicComponent only renders component types. Override BuildRenderTree and call builder.OpenElement(0, $"h{level}"). Covers attribute splatting, why the tag name must be clamped before it reaches the DOM, why changing the level rips the element out of the DOM even with @key, and an auto-levelling variant built on a cascading value.

There is no HasBeenEnumerated flag on IEnumerable<T>. Here is what TryGetNonEnumeratedCount actually checks, why Enumerable.Range passes an ICollection<T> test, and the guard that avoids a wasted ToList().

Declare a generic extension block with a struct, Enum constraint and you get Status.Values, Status.Count, and Status.Parse on every enum in your solution. The receiver shape, the CS0704 and CS0428 traps, and why you must cache Enum.GetValues.

A bool helper method throws "could not be translated". An Expression<Func<T, bool>> does not. Here is how to compose, nest, and reuse expression trees in EF Core 11 without LINQKit, with the real SQL for every case.