Debug.Assert vs Exception Throwing

Question

I\'ve read plenty of articles (and a couple of other similar questions that were posted on StackOverflow) about how and when to use assertions, and I understood the

Answer 1

Though I agree that your reasoning is plausible -- that is, if an assertion is violated unexpectedly, it makes sense to halt execution by throwing -- I personally would not use exceptions in the place of assertions. Here's why:

As others have said, assertions should document situations that are impossible, in such a manner that if the allegedly impossible situation comes to pass, the developer is informed. Exceptions, by contrast, provide a control flow mechanism for exceptional, unlikely, or erroneous situations, but not impossible situations. For me, the key difference is this:

• It should ALWAYS be possible to produce a test case which exercises a given throw statement. If it is not possible to produce such a test case then you have a code path in your program which never executes, and it should be removed as dead code.

• It should NEVER be possible to produce a test case which causes an assertion to fire. If an assertion fires, either the code is wrong or the assertion is wrong; either way, something needs to change in the code.

That's why I would not replace an assertion with an exception. If the assertion cannot actually fire, then replacing it with an exception means you have an untestable code path in your program. I dislike untestable code paths.