Why is TaskCanceledException thrown and does not always breaks into the debugger

Question

I\'m digging into the async-await mechanism and observed the throwing of a TaskCanceledException that I can\'t explain yet.

In the sample b

Answer 1

If you replace the Func with a method, it passes.

    private static async Task TestNullCase()
    {
        // This does not throw a TaskCanceledException
        await Task.Run(() => 5);

        // This does throw a TaskCanceledException
        await Task.Run(() => GetNull());
    }

    private static object GetNull()
    {
        return null;
    }

UPDATE

After letting ReSharper convert both lambdas to variables:

    private static async Task TestNullCase()
    {
        // This does not throw a TaskCanceledException
        Func func = () => 5;
        await Task.Run(func);

        // This does throw a TaskCanceledException
        Func function = () => null;
        await Task.Run(function);
    }

So, the second form is incorrectly interpreted as Func instead of your intent, which I believe is Func