add dot_to_package fn like rprojroot

[mpadge]

This enables write_codemetar to be called from anywhere within a package directory structure. It is essentially a hard-coded version of what rprojroot does to locate the root of an R package. Pretty sure it has no effects on anything else, as it's only evoked when pkg = ".".

library(codemetar) # current version prior to this PR
setwd (<path>/<to>/<local>/<codemetar>)
setwd("./R")

write_codemeta()
#> Error: File `./DESCRIPTION' does not exist

That's annoying because it does exist! With this PR:

devtools::load_all (".", export_all = FALSE) # Version with this PR
#> Loading codemetar
write_codemeta()
#> … Getting CRAN metadata from RStudio CRAN mirror
#> ✔ Got CRAN metadata!
#> codemetar has the highest opinion of this R package :-)
#> … Getting Bioconductor metadata
#> ✔ Got Bioconductor metadata!
#> … Getting sysreqs URL from sysreqs API
#> ✔ Got sysreqs URL from sysreqs API!
#> … Asking README URL from GitHub API
#> ✔ Got README URL!
#> … Asking README URL from GitHub API
#> ✔ Got README URL!
#> … Getting repo topics from GitHub API
#> ✔ Got repo topics!

^{Created on 2021-02-16 by the reprex package (v1.0.0)}

That's better!

[mpadge]

@cboettig You're like going to have to opine here somewhere, because this PR attempts to make functionality less strictly dependent on exact pkg location, but you comment in #303 about overloading the pkg argument. I'm not sure what you mean there, since the is_package function is just

  all(c("DESCRIPTION", "NAMESPACE", "man", "R") %in% dir(path))  # where `path` is passed as `pkg`

That's clearly only looking for source directories, and is not overloaded. So to the extent that it is not, I would suggest you might be best off first merging this PR, then getting @ThierryO to extend PR #303 to ensure that the pkg argument is "taken into account" for all functions. If, on the other hand, pkg is actually overloaded elsewhere, then you'll need to do some deeper thinking about reconciling these two issues.

[maelle]

Thanks a ton @mpadge! This sounds like an useful feature.

Can you make the PR to dev?

[maelle]

Could you please add rprojroot as a dependency? We'd still be under 20 Imports.