dotnet▌

Generate wrapper interfaces and DI registration for hard-to-test static dependencies in C#. Produces IFileSystem, IEnvironmentProvider, IConsole, IProcessRunner wrappers, or guides adoption of TimeProvider and IHttpClientFactory. USE FOR: generate wrapper for static, create IFileSystem wrapper, wrap DateTime.Now, make static testable, make class testable, create abstraction for File.*, generate DI registration, TimeProvider adoption, IHttpClientFactory setup, testability wrapper, mock-friendly interface, mock time in tests, create the right abstraction to mock, how to mock DateTime, test code using File.ReadAllText, what abstraction for Environment, how to make statics injectable, adopt System.IO.Abstractions, make file calls testable. DO NOT USE FOR: detecting statics (use detect-static-dependencies), migrating call sites (use migrate-static-to-wrapper), general interface design not about testability.

Project-wide code coverage and CRAP (Change Risk Anti-Patterns) score analysis for .NET projects. Calculates CRAP scores per method and surfaces risk hotspots — complex code with low coverage that is dangerous to modify. Use to diagnose why coverage is stuck or plateaued, identify what methods block improvement, or get project-wide coverage analysis with risk ranking. USE FOR: coverage stuck, coverage plateau, can't increase coverage, what's blocking coverage, coverage gap, CRAP scores, risk hotspots, where to add tests, coverage analysis, coverage report. DO NOT USE FOR: targeted single-method CRAP analysis (use crap-score), writing tests, running tests without coverage, or troubleshooting test execution (use run-tests).

Make .NET projects compatible with Native AOT and trimming by systematically resolving IL trim/AOT analyzer warnings. USE FOR: making projects AOT-compatible, fixing trimming warnings, resolving IL warnings (IL2026, IL2070, IL2067, IL2072, IL3050), adding DynamicallyAccessedMembers annotations, enabling IsAotCompatible. DO NOT USE FOR: publishing native AOT binaries, optimizing binary size, replacing reflection-heavy libraries with alternatives. INVOKES: no tools — pure knowledge skill.

Helps find, inspect, and compare .NET project templates. Resolves natural-language project descriptions to ranked template matches with pre-filled parameters. USE FOR: finding the right dotnet new template for a task, comparing templates side by side, inspecting template parameters and constraints, understanding what a template produces before creating a project, resolving intent like "web API with auth" to concrete template + parameters. DO NOT USE FOR: actually creating projects (use template-instantiation), authoring custom templates (use template-authoring), MSBuild or build issues (use dotnet-msbuild plugin), NuGet package management unrelated to template packages.

Provides file paths to language-specific extension files for the code-testing pipeline. Call this skill to discover available extension guidance files (e.g., dotnet.md for .NET, cpp.md for C++). Do not use directly — invoked by code-testing agents and skills that need language-specific references.

Creates .NET projects from templates with validated parameters, smart defaults, Central Package Management adaptation, and latest NuGet version resolution. USE FOR: creating new dotnet projects, scaffolding solutions with multiple projects, installing or uninstalling template packages, creating projects that respect Directory.Packages.props (CPM), composing multi-project solutions (API + tests + library), getting latest NuGet package versions in newly created projects. DO NOT USE FOR: finding or comparing templates (use template-discovery), authoring custom templates (use template-authoring), modifying existing projects or adding NuGet packages to existing projects.

Enable nullable reference types in a C# project and systematically resolve all warnings. USE FOR: adopting NRTs in existing codebases, file-by-file or project-wide migration, fixing CS8602/CS8618/CS86xx warnings, annotating APIs for nullability, cleaning up null-forgiving operators, upgrading dependencies with new nullable annotations. DO NOT USE FOR: projects already fully migrated with zero warnings (unless auditing suppressions), fixing a handful of nullable warnings in code that already has NRTs enabled, suppressing warnings without fixing them, C# 7.3 or earlier projects. INVOKES: Get-NullableReadiness.ps1 scanner script.

Write new MSTest unit tests and implement concrete fixes in existing MSTest code using MSTest 3.x/4.x modern APIs and best practices. USE FOR: write unit tests for a class, write MSTest tests, create test class, fix test assertions, MSTest assertion APIs (StartsWith, EndsWith, MatchesRegex, IsGreaterThan, IsInRange, HasCount, IsNull), something seems off with my tests, review tests and fix issues, fix swapped Assert.AreEqual arguments, replace ExpectedException with Assert.Throws, modernize test patterns, convert DynamicData to ValueTuples, data-driven tests, test lifecycle setup, sealed test classes, async test patterns, cancellation token testing, test parallelization, Parallelize, DoNotParallelize, MSTest.Sdk project setup. DO NOT USE FOR: broad test quality audits or test smell detection (use test-anti-patterns), running tests (use run-tests), MSTest version migration (use migrate-mstest-v1v2-to-v3 or migrate-mstest-v3-to-v4).

Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need detection logic.

Analyzes test suites and tags each test with a standardized set of traits (e.g., positive, negative, critical-path, boundary, smoke, regression). Use when the user wants to categorize, audit, or label tests with traits. Do not use for writing new tests, running tests, or migrating test frameworks.