Write Tests

Migrate MSTest v1/v2 projects to MSTest v3, and fix v1/v2-to-v3 breaking changes that surface after the packages are already at 3.x. USE FOR: removing v1 Microsoft.VisualStudio.QualityTools.UnitTestFramework assembly references; moving MSTest.TestFramework/TestAdapter 1.x-2.x to 3.x, the MSTest metapackage, or MSTest.Sdk; tests that broke after a 2.x-to-3.x bump -- CS0411/CS1503 on Assert.AreEqual/AreNotEqual/AreSame once the object overloads became generic, and DataRow strict type matching (1L vs 1) that builds with MSTEST0014 but fails at run time; .testsettings/LegacySettings to .runsettings (DeploymentEnabled, per-test MSTest TestTimeout); v3 timeout behavior; TFMs v3 dropped (net5.0, .NET Fx below 4.6.2, netstandard1.0). Applies even when the project already references MSTest 3.x, if a v1/v2-era setting or error remains. Keeps the current runner. DO NOT USE FOR: MSTest v4 (use migrate-mstest-v3-to-v4 next), clean v3 projects with no v1/v2 leftovers, other test frameworks, or VSTes

Fix build errors and breaking changes after upgrading MSTest v3 to v4, or plan a complete v3-to-v4 migration. Use when user says "upgrade to MSTest v4", "MSTest 4 migration", "MSTest v4 breaking changes", "tests don't compile after upgrading MSTest 3.x to 4.x", or hits CS0507, CS0103, CS1061, CS1615 after updating MSTest packages to 4.x. USE FOR: Execute to ExecuteAsync, CallerInfo ctor on TestMethodAttribute, sealed custom attributes, ClassCleanupBehavior removal, TestContext.Properties Contains to ContainsKey, Assert.ThrowsException to ThrowsExactly, Assert.IsInstanceOfType out param removal, ExpectedExceptionAttribute removal, TestTimeout enum removal, [TestMethod("name")] to DisplayName syntax, TreatDiscoveryWarningsAsErrors, TestContext.TestName in ClassInitialize, MSTest.Sdk MTP changes, dropped TFMs (net6.0/net7.0 to net8.0+). DO NOT USE FOR: MSTest v1/v2 to v3, or errors left from a 2.x-to-3.x upgrade (use migrate-mstest-v1v2-to-v3 first); test framework conversions; general .N

Migrates .NET test projects from xUnit.net v2 to xUnit.net v3. USE FOR: upgrading xunit to xunit.v3. DO NOT USE FOR: migrating between test frameworks (MSTest/NUnit to xUnit.net), migrating from VSTest to Microsoft.Testing.Platform (use migrate-vstest-to-mtp). For xUnit v3 MTP filter syntax (--filter-class, --filter-trait, --filter-query), also load migrate-vstest-to-mtp.

Guide for creating effective skills. This command should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations. Use when creating new skills, editing existing skills, or verifying skills work before deployment - applies TDD to process documentation by testing with subagents before writing, iterating until bulletproof against rationalization

Rstest best practices for config, CLI workflow, test writing, mocking, snapshot testing, DOM testing, coverage, multi-project setup, CI integration, performance and debugging. Use when writing, reviewing, or troubleshooting Rstest test projects.

Guidance for configuring dependency injection in .NET MAUI apps — service registration in MauiProgram.cs, lifetime selection (Singleton / Transient / Scoped), constructor injection, Shell navigation auto-resolution, platform-specific registrations, and testability patterns. USE FOR: "dependency injection", "DI setup", "AddSingleton", "AddTransient", "AddScoped", "service registration", "constructor injection", "IServiceProvider", "MauiProgram DI", "register services", "BindingContext injection". DO NOT USE FOR: data binding (use maui-data-binding), Shell route configuration (use maui-shell-navigation), unit-test mocking frameworks (use standard xUnit and NSubstitute patterns).