Things not clear to me which could be added to the description:

• what to do when we encounter an object: should we check if any of its fields has value of 42? I do not check that, and my solution passes.
• should we check items contained in iterables, like Set or Map?
• what should be returned for items which fall into multiple categories: let data = function( ) { return 42; }; data.someProperty = 42;

I'm pretty sure deep search of an element is duplicate to an existing kata.

Well, maybe except this kata also has functions. But otherwise it's nothing new.

For sure!
only one test? WTF?

I think this kata needs some better test cases!

Thank you, much better :D

Random test cases added

OK, random test cases added. First Kata authored, never occured to me that anyone would waste their time providing obvious cheat solutions. Will bear this in mind in future.

I second this.