domains / families / software-engineering / writing-mstest-tests

writing-mstest-tests

separate

ALWAYS USE when asked to fix, rewrite, update, improve, modernize, show corrected code for, or explain existing MSTest tests or MSTest-specific configuration. Use for "review" when corrected code or edits are wanted, even for one pasted assertion or passing tests with bad failure output. Covers expected/actual labels; generic Boolean, collection, string, numeric, null, identity, exception, hard-cast, and object[] checks; TestContext/lifecycle; timeout/cancellation; OS/CI conditions, retry, cleanup, parallelization, MSTest.Sdk project setup, and MSTESTxxxx. Honor the installed MSTest version. DO NOT USE to design new test cases (code-testing), perform report-only audits, create project files rather than explain MSTest setup, run tests, migrate frameworks, or handle non-MSTest/non-.NET code.

When to use

• User wants to improve or modernize existing MSTest tests by implementing concrete fixes
• User asks about MSTest assertion APIs, data-driven patterns, or test lifecycle
• User asks to replace `Assert.IsTrue` with more specific assertions (collections, nulls, types, comparisons)
• User asks to replace hard casts with type-checking assertions in tests
• User needs help fixing a specific MSTest test bug or failing assertion
• User asks to fix swapped `Assert.AreEqual` argument order (expected first, actual second)
• User asks to convert `DynamicData` from `IEnumerable<object[]>` to ValueTuple-based data
• User asks to fix or understand an MSTest analyzer diagnostic (an `MSTESTxxxx` warning/error)

When not to use

• User needs a test quality audit, anti-pattern detection, or flaky-test investigation (use `test-anti-patterns`)
• 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)

Skill page

Source