New check_doc_fields()

[hadley]

Fixes #2525

@gadenbuie can you take a look too please? I think this should be a nice tool for a coding agent to verify that it's updated all the needed docs.

[gadenbuie]

I've never used it, but I just discovered check_man(). Should this function name be check_man_fields() then? Or roll these checks into check_man(), maybe behind a flag?

It'd be nice to have one function for coding agents. I think agents also tend to call document() separately, so it'd be nice to skip documenting by default to speed up the check. So something like this

check_man <- function(pkg = ".", document = FALSE, check_fields = TRUE) {
  # ...
}

[hadley]

I'm not convinced that check_man() is that helpful. It can save you a little time compared to R CMD check but I generally find it detects problems that we don't tend to make any more.

[gadenbuie]

I agree for human usage, but at a quick glance I think check_man() would catch mistakes that are common among coding assistants. In particular, updating a function signature but not documenting the parameter is a common coding agent miss. In my experience, check_man() is much faster than a full check() (2s vs a full minute or more in btw for example).

That said, I haven't fully looked into what's covered by check_man()