List.dropAt drops the wrong index

[ageron]

It looks like List.dropAt is currently broken:

  The rockin' roc repl
────────────────────────

Enter an expression, or :help, or :q to quit.

» [0,10,20,30,40,50] |> List.dropAt 0

[10, 20, 30, 40, 50] : List (Num *)               <-- OK
» [0,10,20,30,40,50] |> List.dropAt 1

[0, 10, 20, 30, 40] : List (Num *)                <-- WRONG!
» [0,10,20,30,40,50] |> List.dropAt 2

[0, 10, 20, 30, 40] : List (Num *)                <-- WRONG!
» [0,10,20,30,40,50] |> List.dropAt 3

[0, 10, 20, 30, 40] : List (Num *)                <-- WRONG!
» [0,10,20,30,40,50] |> List.dropAt 4

[0, 10, 20, 30, 40] : List (Num *)                <-- WRONG!
» [0,10,20,30,40,50] |> List.dropAt 5

[0, 10, 20, 30, 40] : List (Num *)                <-- OK
» [0,10,20,30,40,50] |> List.dropAt 6

[0, 10, 20, 30, 40, 50] : List (Num *)            <-- OK

[ageron]

$ roc version
roc nightly pre-release, built from commit 9a4d556 on Sat Sep  7 09:02:00 UTC 2024

[ageron]

I'm really surprised this regression didn't break any tests.
It looks like none of the existing test cases cover the case where you drop at an index in the middle of the list. As a result, none of the tests go past this line in the Zig implementation.

[Anton-4]

Thanks for the investigation @ageron!
We should definitely:

• add failing examples to the tests