Strange, These days very little to zero development happens without IDEs. I don't really know why anybody should expect to test somebody's skills without an IDE.
That's because today a term called 'Productivity' has become massively more important than any thing else. Its something like this, Lets say there is an archer. He can shoot the red dot 9/10 of times with his bow and arrow. You take away the bow and arrow and give him stones and ask him to match the same 9/10 hits on the red dot. Guess what, he won't be able to, May be with time he can. But for the time being he can't.
What does this say? Does this mean he is a bad archer? No. Tools and their usage is part of the trade.