NUnit catching TargetInvocationException instead of the real exception

[RTodorov]

framework: netcoreapp1.0 nunit: 3.4.1 dotnet-test-nunit: 3.4.0-beta-2 os: macosx 10.11 (El Capitain)

When asserting for an exception, my test will always fail:

    Expected: <My.System.Exceptions.InsufficientBalanceException>
    But was:  <System.Reflection.TargetInvocationException>

Any exception is being caught as a TargetInvocationException.

I'm not sure if the problem is related to NUnit or the test runner, I'm sorry if this is the wrong place to file this issue!

Thank you!

[RTodorov]

Some extra detail:

2) Failed : My.System.Test.AccountTest.CannotWithdrawFromAccountWithoutBalance
  Expected: <My.System.InsufficientBalanceException>
  But was:  <System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> My.System.InsufficientBalanceException: Exception of type 'My.System.InsufficientBalanceException' was thrown.
   at My.System.Account.Apply(PointsSpent e) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/Account/Account.cs:line 45
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at My.System.PrivateReflectionDynamicObject.InvokeMemberOnType(Type type, Object target, String name, Object[] args) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/PrivateReflectionDynamicObject.cs:line 45
   at My.System.PrivateReflectionDynamicObject.TryInvokeMember(InvokeMemberBinder binder, Object[] args, Object& result) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/PrivateReflectionDynamicObject.cs:line 25
   at CallSite.Target(Closure , CallSite , Object , IEvent )
   at CallSite.Target(Closure , CallSite , Object , IEvent )
   at CallSite.Target(Closure , CallSite , Object , IEvent )
   at My.System.AggregateRoot.ApplyChange(IEvent event, Boolean isNew) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/AggregateRoot.cs:line 51
   at My.System.AggregateRoot.ApplyChange(IEvent event) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/AggregateRoot.cs:line 44
   at My.System.Account.Withdraw(int amount) in /Users/myuser/Projects/CSHARP/My.System/src/My.System/Account/Account.cs:line 25
   at My.System.Test.AccountTest.<>c__DisplayClass6_0.<CannotWithdrawFromAccountWithoutBalance>b__0() in /Users/myuser/Projects/CSHARP/My.System/test/My.System.Tests/AccountTest.cs:line 53
   at NUnit.Framework.Assert.Throws(IResolveConstraint expression, TestDelegate code, String message, Object[] args)>

Assert code:

Assert.Throws<InsufficientBalanceException>(() => account.Withdraw(100));

[RTodorov]

Nevermind, my PrivateReflectionDynamicObject was wrapping the real exception on a TargetInvocationException. My bad!

[rprouse]

Thanks for the update :+1:

[CharliePoole]

It's an interesting issue actually... NUnit calls tests by reflection and when an exception occurs it is almost always seen as a TargetInvocationException. We report the InnerException. But in this case, the InnerException was another TargetInvocationException... perhaps we should show more info about exceptions with inner exceptions once they arrive at the runner level.

[RTodorov]

Well, in case you need more details, the code I'm using came from here:

https://github.com/gautema/CQRSlite/blob/master/Framework/CQRSlite/Infrastructure/PrivateReflectionDynamicObject.cs

The TargetInvocationException was being thrown on this line:

https://github.com/gautema/CQRSlite/blob/master/Framework/CQRSlite/Infrastructure/PrivateReflectionDynamicObject.cs#L46

What I did to "fix" it:

try {
    return member.Invoke(target, args);
} catch (TargetInvocationException ex) {
    throw ex.InnerException;
}

[jcansdale]

Doesn't it already show inner exceptions? I related question is whether it filters stack traces of inner exceptions (e.g. removes Assert stack frames). I know it doesn't with System.AggregateException, so it probably doesn't with inner exceptions either. Should we add this as a feature request?

[CharliePoole]

I mentioned it because I don't know what dotnet-test-nunit does.

NUnit framework would need to be looked at for exceptions that are caught and reported as errors.