• The description is written in broken English
• It is not explained what "front face" does
• My solution ignores "F" turns, as I assumed that they do nothing, but the author's solution changes direction to "F" - if that's the indended behavior, it should be properly tested
• It is not stated how to handle lowercase letters
• The "random" tests are not actually random
• Trivial map/filter/reduce is not a novel kata idea (I also vaguelly remember doing something similar in a different kata, although idk whether it was the whole task, or just a part of it, so this might be a duplicate too)

input: 'RL'
outcome: 'F' should equal 'B'

why?

wouldn't you turn right, then turn back left, and then immediately be facing front again?

no actual description.

• What are the inputs?
• what is actually meaningful in them (that part is covered, but it's rather hard to see what are the data or not for now)
• outputs are never described

No random tests.

Writing a trivial comparator is a duplicate.