Is it possible to include HEEX files in the coverage?

[thbar]

@ChristianAlexander raised this interesting issue a few months ago (and today I wonder the same), I thought it would be worth creating an issue here, to give this problem a bit more visibility:

https://elixirforum.com/t/heex-template-files-not-included-in-code-coverage/47572

Since the HEEX templates are compiled into functions, I presume there would be a way to make this work (and it would provide a lot of maintenance value, to figure out which templates are actually rendered during the tests).

My understanding is that excoveralls relies on Erlang's cover (https://github.com/parroty/excoveralls/blob/master/lib/excoveralls/cover.ex), but I'm not sure yet where the fix would need to go, if one can be found.