Wrapped AggregateException reports just first exception in ToString method

Question

I get complete set of nested exceptions when I use ToString() method on AggregateException directly:

public void GreenTest()
{
    var ex = new AggregateException(new Exception("ex1"), new Exception("ex2"));

    ex.ToString()
        .Should()
        .Contain("ex1")
        .And
        .Contain("ex2");
}

The problem is I get only the first exception when the AggregateException is wrapped in another exception:

public void RedTest()
{
    var ex = new Exception("wrapper", new AggregateException(new Exception("ex1"), new Exception("ex2")));

    ex.ToString()
        .Should()
        .Contain("wrapper")
        .And
        .Contain("ex1")
        .And
        .Contain("ex2");
}

ex2 isn't present in the resulting string. Is this a bug or some well-known feature of AggregateException class?

Answer 1

I think not that this is a bug. More a normal behavior

The problem is that the ToString() on Exception will not call the ToString() of the innerException, but the private ToString(bool,bool) method on the exception class itself.

So the overridden ToString() method of the AggregateException is not called.

The constructor of the AggregateException will set the innerException to the first exception passed to the constructor.

In your case this is new Exception("ex1")