Don’t Lose your HEAD over Default Branches

Read on for a little trick to always get the default branch…

While git has no “default” branch, online code platforms such as GitHub need to define a default for the branch that someone sees when they look at code online. While the community standard for the default branch is now becoming main instead of master¹, and while the switch for any repo is rather easy and is well supported by usethis, for a while (forever) there will still be repos with different default branches in the wild.² Especially as nothing prevents you from using any other name for the default branch (although this could trip up collaborators).³

So, what to deal with the existence of different possible default branches?

• usethis tooling regarding default branches including usethis::git_default_branch(), is very handy.
• You can also use gert directly, e.g. gert::git_remote_ls() will help show you remote references. The symref for ref contains the default branch name.

gert::git_remote_ls() |>
head() # another useful thing named head
#> ref symref
#> 1 HEAD refs/heads/main
#> 2 refs/heads/1password <NA>
#> 3 refs/heads/2fa <NA>
#> 4 refs/heads/email <NA>
#> 5 refs/heads/fix_author_links <NA>
#> 6 refs/heads/footnotes <NA>
#> oid
#> 1 2ef29132be682883d1c12a957c38e1fa6599898f
#> 2 e4f3ef36c453dd2ede5a091c7d3f5f32c609caca
#> 3 7461f15e81651d5bbf6dcab078801cfa35e2f039
#> 4 6f8c849ef325dc597e819bffbd8829afa05ae414
#> 5 2f328db8fc6ce94caa50ddde7a0b021178818d8f
#> 6 f552c2dcac79228e929e65975c52484f5655577c

gert::git_remote_info() shows the head for a given remote:

gert::git_remote_info("origin")
#> $name
#> [1] "origin"
#> 
#> $url
#> [1] "git@github.com:ropensci/roweb3.git"
#> 
#> $push_url
#> NULL
#> 
#> $head
#> [1] "refs/remotes/origin/main"
#> 
#> $fetch
#> [1] "+refs/heads/*:refs/remotes/origin/*"
#> 
#> $push
#> character(0)

• When linking to a file, or trying to download the same path from a gaggle of repositories, think of the HEAD reference! I.e. instead of linking to a file via https://github.com/<owner>/<repo>/tree/<default-branch>/<path> where you need to know what the default branch is, you can link to https://github.com/<owner>/<repo>/tree/HEAD/<path> that will always point to the latest version of the path in the default branch. Similarly, for raw content (to download), you can use links à la https://github.com/<owner>/<repo>/raw/HEAD/<path>.

In conclusion, master or main? Hit the nail on the HEAD. 😉

1. For more context on Terminology, Power and Oppressive Language see for instance https://tools.ietf.org/id/draft-knodel-terminology-00.html ↩︎

2. Actually, this post was the occasion to change the default branch for the source of this website! ↩︎

3. Some repos only have a branch called gh-pages (e.g. everything under https://github.com/ropensci-docs), in which case that is the default branch. ↩︎