NS5000 when checking if an event subscription was received.

[LiTo96]

Since Version 1.0.16 the analyzer rule NS5000 alerts code like:
sub.Received(1).PropertyChanged += MyPropertyChangedHandler;

ErrorMessage:
NS5000: Unused received check. To fix, make sure there is a call after "Received". Correct: "sub.Received().SomeCall();". Incorrect: "sub.Received();"

[tpodolak]

@dtchepak I am trying to add valid test case for this scenario and I came up with this

using NSubstitute;
using System;
using Xunit;

namespace MyNamespace
{
    public class Foo
    {
        public event Action SomeEvent;
    }

    public class FooTests
    {
        [Fact]
        public void Test()
        {
            var substitute = NSubstitute.Substitute.For<Foo>();
            substitute.Received().SomeEvent += Arg.Any<Action>();
        }
    }
}

However, this test passes, even though SomeEvent was not fired - according to docs
it is one of the way of asserting if event subscription was received. Is this valid test case in this case or there is regression in NSubstitute?

[dtchepak]

This is because the member is not virtual. Running multiple tests including this one gives me:

  Error Message:
   NSubstitute.Exceptions.RedundantArgumentMatcherException : Some argument specifications (e.g. Arg.Is, Arg.Any) were left over after the last call.

If it is virtual it fails as expected.

  Error Message:
   NSubstitute.Exceptions.ReceivedCallsException : Expected to receive a call matching:
        SomeEvent += any Action
Actually received no matching calls.

[tpodolak]

Ahh right. I dont know why I thought that events were handled differently. Will update my PR accordingly

[jm-atbas]

Can you release an update with this fix to NuGet, please?