Work with empty markdown files

[hadley]

Fixes #2309

Rather than erroring, I just made it return nothing, which seems most consistent with the other ways we process markdown.

[maelle]

It works (see below) but why not adapt the behavior of path_first_existing()? (though I know path_first_existing() is used elsewhere too)

usethis::create_package("../empty")
#> ✔ Creating '../empty/'
#> ✔ Setting active project to '/tmp/RtmpYBW6yl/empty'
#> ✔ Creating 'R/'
#> ✔ Writing 'DESCRIPTION'
#> Package: empty
#> Title: What the Package Does (One Line, Title Case)
#> Version: 0.0.0.9000
#> Authors@R (parsed):
#>     * First Last <first.last@example.com> [aut, cre] (YOUR-ORCID-ID)
#> Description: What the package does (one paragraph).
#> License: `use_mit_license()`, `use_gpl3_license()` or friends to pick a
#>     license
#> Encoding: UTF-8
#> Roxygen: list(markdown = TRUE)
#> RoxygenNote: 7.3.1
#> ✔ Writing 'NAMESPACE'
#> ✔ Setting active project to '<no active project>'
fs::file_create("../empty/README.md")
pkgdown::build_site("../empty")
#> ── Installing package empty into temporary library ─────────────────────────────
#> ── Building pkgdown site for package empty ─────────────────────────────────────
#> Reading from: /tmp/RtmpYBW6yl/empty
#> Writing to: /tmp/RtmpYBW6yl/empty/docs
#> ── Initialising site ───────────────────────────────────────────────────────────
#> Copying
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/bootstrap-toc.css,
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/bootstrap-toc.js,
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/docsearch.css,
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/docsearch.js,
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/link.svg,
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/pkgdown.css,
#> and
#> ../../../home/maelle/R/x86_64-pc-linux-gnu-library/4.2/pkgdown/BS3/assets/pkgdown.js
#> to bootstrap-toc.css, bootstrap-toc.js, docsearch.css, docsearch.js, link.svg,
#> pkgdown.css, and pkgdown.js
#> ── Building home ───────────────────────────────────────────────────────────────
#> Writing `authors.html`
#> Writing `404.html`
#> ── Building function reference ─────────────────────────────────────────────────
#> Writing `reference/index.html`
#> Writing sitemap.xml
#> ── Finished building pkgdown site for package empty ────────────────────────────
#> ── Finished building pkgdown site for package empty ────────────────────────────

^{Created on 2024-04-18 with reprex v2.1.0}

[maelle]

ah no it makes sense 🤦‍♀️