Ah makes sense, the other test cases that expected an error declared that though.

Great kata so far, I'm not understanding the feedback from a failed test case

Here's a psuedo stack trace:

imp is stack command
push n
parse number 1 signValue 1
imp is stack command
push n
parse number 2 signValue 1
imp is stack command
push n
parse number 3 signValue 1
imp is stack command
parse number 32 signValue -1
(slide) discard number n -32
post slide stack [ 3 ]
imp is io commands
output number, stack [ 3 ]
imp is io commands
output number, stack []
top is undefined
imp is flow commands
quit called

output '3'
output length 1

Expecting only one value for slide with out of bounds index

So it's pushing 1,2,3 then removing everything except 3 using slide and outputting that twice, which should result in a single string of 3?