C# - Exclude lambda expression from code coverage

Question

I have a particular third party class that has an event handler. I have setup MyEventHandler method which I am able to test using reflection, so I know that is well tested. However I am getting a missing line coverage where I setup the handler (since that part is never being called). How can I Exclude that from code coverage somehow? MyClass object is a sealed class so I can not mock it and invoke the handler via test.

MyClass myObj = new(); // sealed class, so can't mock using moq

myObj.OnEvent += () => 
    {
        MyEventHandler(); // This line is uncovered
    }

Things I have tried.

Making entire handler as a method, however again the actual lambda expression is still shown uncovered.
Marked the above method of setup with ExcludeFromCodeCoverage
I have also tried using runsettings file, which works however due to the GeneratedCodeAttribute/CompilerGeneratedAttribute exclusion, it also excludes my async functions, which is not desired.

How do I exclude the lambda expression from code coverage?

is the event-handler unconvered, or the assignment of that handler to the event? — MakePeaceGreatAgain, Jun 03 '22 at 08:57
So the assignment is your own code, yet you have no way of executing that statement in your test? How does that make sense? — Good Night Nerd Pride, Jun 03 '22 at 09:00
Sorry maybe there's some confusion. The assignment line itself is covered. However since I can not invoke the event the lambda expression part is shown uncovered. I am also able to invoke the actual method so that is covered. I have split the handler on multiple lines to make it clearer. — touchofevil, Jun 03 '22 at 09:03

score 0 · Accepted Answer · answered Jun 03 '22 at 09:41

Okay so got this resolved. I am still posting here in case if it helps others in future. I have marked the event with [ExcludeFromCodeCoverage] and that seems to exclude the event which in this case is what I wanted.

MyClass myObj = new();

myObj.OnEvent += [ExcludeFromCodeCoverage] () => 
    {
        MyEventHandler();
    }

C# - Exclude lambda expression from code coverage

1 Answers1

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