What is the default for revdep_check(dependencies=), exactly?

[MichaelChirico]

revdepcheck/R/revdepcheck.R

Line 39 in 5a0c138

#' release, we recommend using the default.

?revdep_check is not clear enough here IMO:

https://revdepcheck.r-lib.org/reference/revdep_check.html

In R, a signature like this is somewhat ambiguous:

revdepcheck/R/revdepcheck.R

Lines 59 to 60 in 5a0c138

	dependencies = c("Depends", "Imports",
	"Suggests", "LinkingTo"),

Because match.arg() often means "here's the enum of possible values, of which the first is chosen"; here that would mean "only downstream Depends are checked", which is "valid" but doesn't make that much sense. So I could guess that the default is "any downstream Depends, Imports, Suggests, or LinkingTo", but it would be better to be more explicit here.

It's not even clear to me from a minute of reading the sources what the behavior is -- I have to jump to another package entirely to understand what's going on. All the more reason to be explicit in the doc page here.