Issues with `Throw` assertions

[vbreuss]

I have a couple of issues with the current implementation of the Throw assertions:

• AutoComplete suggests two generic overloads, which I must not use First I thought, that I could specify the type of the Exception, but I have to use .ThrowsException().OfType<ArgumentException>(() instead of ThrowsException<ArgumentException>()
• When awaiting Assert.That(action).ThrowsException() I don't get the exception back to make further assertions on it
• I cannot combine multiple assertions on an exception, as the .With.Message does not keep the reference to the original exception.

My suggestion is to refactor the delegate assertions as follows:

• The main entry point is .Throws() which removes the generic overload of TActual from subsequent calls
• Then we have
  • .Nothing() (no exception is thrown)
  • .Exception() (any exception is thrown)
  • .OfType<TException>() (an exception of type TException or any subtype is thrown)
  • .Exactly<TException>() (an exception of type TException is thrown)
• For all thrown exceptions we have
  • .WithMessage(string) (checks that the message is equal)
  • .WithMessageMatching(string) (checks that the message matches the (wildcard) pattern)
  • WithInnerException() which allows checks on the inner exception

I created draft PR #870 to show, how this could be implemented...

[thomhurst]

Funny timing, I actually started the work on casting objects back for some assertions last night:

https://github.com/thomhurst/TUnit/pull/869/files

[vbreuss]

My PR is currently more a proof of concept, so I am happy to adapt it to incorporate your changes, if you agree to the overall API changes...