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.