Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
Upgrading C# and .NET: Moving an Old Project to .NET 10
Moving a .NET 6 project to .NET 10: the support calendar, how LangVersion relates to the TFM and the latest trap, pinning the SDK with global.json, reading the real CS8981 and CS9258 warnings, the silent behavior change of the field keyword and reading breaking-change pages; C# 15 gets its own post.
What's New in C# 14: Extension Members, field and Null-Conditional Assignment
C# 14 next to its C# 10 and C# 13 equivalents: null-conditional assignment skipping the right-hand side, extension properties, static extension members and extension operators, the field keyword, arrays converting to spans, nameof(List<>), lambda parameter modifiers, partial constructors/events and compound assignment operators.
What's New in C# 13: params Collections, Lock and Partial Properties
C# 13 next to its C# 10 equivalents: the new Lock type and the CS9216 trap, params collections with an allocation measurement, ref structs implementing interfaces and allows ref struct, partial properties, OverloadResolutionPriority, the \e escape and ^ indexes in initializers.
What's New in C# 12: Primary Constructors and Collection Expressions
C# 12 next to its C# 10 equivalents: why a primary constructor is a parameter rather than a property and the CS9124 warning, square-bracket collection expressions and spread, default lambda parameters, alias any type, inline arrays, the Experimental attribute and a note on interceptors.
What's New in C# 11: Raw Strings, required and List Patterns
How we wrote it in C# 10 and how we write it in C# 11: raw string literals and the culture trap, required members and SetsRequiredMembers, list patterns, generic math with its language and library legs, file-local types and UTF-8 literals.
C# Versions: A Short History from 1.0 to 10
The signature features, release dates and .NET pairings of every version from C# 1.0 to C# 10; compiling the same code with different LangVersion values to see how the compiler tells you which feature came from which version.
Unit Testing in C#: xUnit, Theory/InlineData and Testable Code
The hidden dependencies behind a flaky test, an xUnit test project, Fact and Assert, Theory/InlineData/MemberData, taking time from outside with IClock, and pitfalls like decimal InlineData and async void.
Dependency Injection Basics in C#: Lifetimes, the Container and Captive Dependencies
Constructor injection with Microsoft.Extensions.DependencyInjection, singleton/scoped/transient, the container's disposal duty, captive dependencies and ValidateScopes, multiple registrations, TryAdd and factories.
Performance in C#: Allocations, Structs and Measuring with BenchmarkDotNet
Why Stopwatch isn't enough, setting up BenchmarkDotNet 0.15.8 and reading its table, the measured difference between classes and structs, hidden allocations from boxing and closures, and benchmark pitfalls.
Source Generators in C#: Generating Code at Compile Time with IIncrementalGenerator
Writing an incremental generator that adds code during the build: the netstandard2.0 project and Roslyn version, the pipeline and caching, seeing the generated code, and the partial and hint name pitfalls.
Interop and unsafe Code in C#: P/Invoke, Pointers and fixed
AllowUnsafeBlocks and pointers, pinning against the GC with fixed, calling libc with DllImport, string marshalling, callbacks with function pointers, and keeping unsafe code small with NativeMemory and spans.
ref Returns, ref Locals, in Parameters and ref struct in C#
Moving values by reference instead of copying them: ref locals, ref returns, ref readonly, the defensive-copy trap with in parameters, readonly structs and writing your own ref struct.