How do you test exception handling in unit tests?

Short answer: Use assertion methods that expect exceptions. For example, in MSTest: [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Method_ShouldThrowException()

Example code

{ myService.DoSomethingInvalid(); } Or in xUnit: await Assert.ThrowsAsync<InvalidOperationException>(() => myService.DoSomethingInvalidAsync());

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.