This is a CodeWars framework bug, where preloaded code (such as BlackKnight) is not loaded until you click Submit, meaning that you can't test your solution. The workaround is just use Submit instead of trying to use tests.

You can, however, write tests in the same frame as your solution goes, or log things from there. Then when you click Submit they'll be run and you can see what the results are before the Kata's solution tests are run.

No worries.

Is this suggestion covered now?

Fair enough. I explicitly explained what is expected in the second paragraph, but I agree that line was misleading. It has now been cut.
Thanks for the feedback~