The Linked List exercise does not need to have a fully functional unshift function, as you can see in my iteration 1. I only implemented the cases for a list with at most 2 elements and it still passes all the tests.
It seems the implication is that there’s missing test case. I’m not keen on adding one though because I’m not sure if there’s much value in adding one to cover this one. I’m not aware of this being a common submission yet and adding a test would require re-running tests on already submitted solutions (1,322 started).
Beside Linked List exercise is also a practice exercise and I think the solution could also implemented in other tracks and pass the tests in the canonical data. So … it probably should be added there to propagate to more tracks, which means having to rerun the tests over more solutions …
For reference, I think the new test to cover this case would need to call unshift on a list with three or more items.