Please add two or three test fixtures for convenience, otherwise this kata is good to go. The first two test cases

Test.assertSimilar(reverseList(null), null);
Test.assertSimilar(reverseList([1, [2, [3, null]]]), [3, [2, [1, null]]]);

should do it.

• The description should be be more verbose in respect to the nature of the report object
• As some others have already said, the report object really should be a static snapshot, not a continuously updating reference
• This kata would benefit from included test fixtures

Otherwise this is a very interesting kata.