I've ended up having a bit of a row in an interview over this kind of thing because people just bias their tests to expectations they don't even have of their current staff. 1000 lines of decent code in 3 days is a rare thing at the best of times.
"we'd like you to just whiteboard some pseudo code for this problem that one of our senior engineers solved recently"
"was he stood in front of multiple people, timed and drawing on a whiteboard when he solved it?"
"no, but we're just wanting to see how you'd approach the problem"
"well, I'd probably do what he did which is Google some stuff, read some stuff, have time to process it, then write some code and then probably restart as I figure out the direction I want, probably bounce an idea off a colleague or two to make sure I'm not just in crazy tunnel vision land and then I might have the makings of a solution. Shall I whiteboard that flow diagram for you?"
"we'd like you to just whiteboard some pseudo code for this problem that one of our senior engineers solved recently"
"was he stood in front of multiple people, timed and drawing on a whiteboard when he solved it?"
"no, but we're just wanting to see how you'd approach the problem"
"well, I'd probably do what he did which is Google some stuff, read some stuff, have time to process it, then write some code and then probably restart as I figure out the direction I want, probably bounce an idea off a colleague or two to make sure I'm not just in crazy tunnel vision land and then I might have the makings of a solution. Shall I whiteboard that flow diagram for you?"
interview ended abruptly at that point