writing-mstest-tests

# Writing MSTest Tests Help users write effective, modern unit tests with MSTest 3.x/4.x using current APIs and best practices. ## When to Use - User wants to write new MSTest unit tests - User wants to improve or modernize existing MSTest tests - User asks about MSTest assertion APIs, data-driven patterns, or test lifecycle - User needs to review MSTest test code for anti-patterns ## When Not to Use - User needs to run or execute tests (use the `run-tests` skill) - User needs to upgrade from MSTest v1/v2 to v3 (use `migrate-mstest-v1v2-to-v3`) - User needs to upgrade from MSTest v3 to v4 (use `migrate-mstest-v3-to-v4`) - User needs CI/CD pipeline configuration - User is using xUnit, NUnit, or TUnit (not MSTest) ## Inputs | Input | Required | Description | |-------|----------|-------------| | Code under test | No | The production code to be tested | | Existing test code | No | Current tests to review or improve | | Test scenario description | No | What behavior the user wants to test | ## Workflow ### Step 1: Determine project setup Check the test project for MSTest version and configuration: - If using `MSTest.Sdk` (`<Sdk Name="MSTest.Sdk">`): modern setup, all features available - If using `MSTest` metapackage: modern setup (MSTest 3.x+) - If using `MSTest.TestFramework` + `MSTest.TestAdapter`: check version for feature availability Recommend MSTest.Sdk or the MSTest metapackage for new projects: ```xml <!-- Option 1: MSTest SDK (simplest, recommended for new p...