With HOCs (react 15), I often have a list of children from some component, with a key on each child, and map over them. The keys needs to be transferred to the new children. This happens automatically using cloneElement, though I can also manually set them if I’m, say, wrapping the unmodified child in a new parent.
The result is unexpected, as instead of (for example) key ‘mykey’, at run-time it looks like ".$.$.$.$mykey’. Or “.$.$.$mykey/.$.$.$.$mykey”. I’m not adding those “.$” or joining them with ‘/’, and I can’t find any docs explaining where this transform is coming from.
It’s problematic, because they often change in ways I don’t know how to control, resulting in burning a lot of cpu on unmount/mount of components. E.g. a key might change from “.$.$.$.$mykey” to “.$.$.$mykey”, causing it to unmount.