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 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)