get_section_level() fails on unnumbered sections

[gustavdelius]

The current implementation of get_section_level() fails on unnumbered sections created in RMarkdown with

# This section is unnumbered {-}

(see https://bookdown.org/yihui/rmarkdown-cookbook/unnumbered-sections.html). This leads to class="section level1 unnumbered which the regular expression in get_section_level() can not deal with.

[hadley]

What problem does that cause?

[gustavdelius]

It makes build_search() throw an error on any site that has Rmarkdown documents with unnumbered sections.

[hadley]

I don't think that can be true because I use unnumbered sections in my books, and search works for me.

[gustavdelius]

O.k., so perhaps not every site. But on an ordinary pkgdown site created for an R package. Try for example making a heading in one of the pkgdown vignettes unnumbered, then run pkgdown::build_articles() and then pkgdown::build_search() and you will see the error.

[hadley]

Oh this is pkgdown, not bookdown. Sorry, I got confused!

[maelle]

@gustavdelius thanks for catching this! 🙏 I've opened a PR.

[gustavdelius]

@maelle , then you can close my pull request for fixing this #1655

[maelle]

oh sorry I had missed it 🤦‍♀️ Your regex might actually be more elegant.