How to handle exceptions thrown by Tasks in xUnit .net's Assert.Throws?

Question

The following asynchronous xUnit.net test with a lambda marked with the async modifier fails by reporting that no exception was thrown

Answer 1

If you also need to return the exception to verify it then this might be useful:

public static async Task AssertThrowsAsync(Func func)
    {
        var expected = typeof (TException);
        Exception exception = null;
        Type actual = null;
        try
        {
            await func();
        }
        catch (Exception e)
        {
            actual = e.GetType();
            exception = e;
        }
        Assert.NotNull(exception);
        Assert.Equal(expected, actual);
        return exception;
    }