Add a new global command to template language rev(revset: String) -> List<Commit>

[Ghoughpteighbteau]

I'm looking to update my draft commit description template to automatically start with the name of the closest bookmark head (same logic as jj tug). I don't think I can accomplish this however, because there's no way to perform a revset query on its own to get potential bookmarks.

Here's what I imagine this would look like:

concat(
  rev("::@- & bookmarks()").map(|c| c.local_bookmarks())),
  coalesce(description, default_commit_description, "\n"),
  surround(
    "\nJJ: This commit contains the following changes:\n", "",
    indent("JJ:     ", diff.stat(72)),
  ),
  "\nJJ: ignore-rest\n",
  diff.git(),
)

I'm not sure if this is a good idea or not, but I used to use a git hook commit-msg to do this.

Personally, I think the approach of appending it to the default message is way way better. That way you can strip the suggested bookmarks if you don't want them in the commit message. But after going through the templating language, I can't see a way to do it.

For context on why I want to do this: It's a common workflow in our company to append the name of the ticket you are working on to the work you did for it. We have some handy dandy scripts that look through the git history and update the status of the ticket with information about what work has been done for a ticket, and where that work is in our release cycle.

All fine and dandy, Unless a squishy human developer fat fingers the ticket ID and suddenly it looks like no work has been done but the ticket got closed.

jujutsu please, I wish for the certainty of steel. 🦾

[PhilipMetzger]

See the discussion in #6891 which is about something similar but not the same

[Ghoughpteighbteau]

I did see that discussion but it appears to be about creating new bookmarks based on... honestly? I'm not actually sure WHAT it's basing it on. I'm not sure what a trailer is... The trailers() function was not documented in the template language (other than its existence)

I went looking here https://jj-vcs.github.io/jj/latest/config/#commit-trailers and I'm honestly still confused as to what they are. Are they just the text in a description after the first line?

Additionally, the .trailers() function could only be applied to the current commit or by parents. It feels like I end up stuck in my previous solution where I just do .parents().parents().parents() with a bunch of if conditions and add any bookmarks I can find. There's no reasonable number of iterations I can use.

So one strategy I could maybe see is by altering the commit_trailers template to always include the previous bookmarks? and the previous trailers that referenced the bookmarks, to carry the information forward. Wouldn't that break if I went jj new, wrote some changes, then jj new again without writing a description?

That said: I really don't understand what trailers are or how they work or what #6891 is doing or how it works :/

[PhilipMetzger]

I did see that discussion but it appears to be about creating new bookmarks based on... honestly?

It's about creating bookmarks based on the commit description which in many companies contains the ticket id, which is similar to your request to have the description populated based upon the closest bookmark.

[yuja]

Perhaps, we can add latest_tags/bookmarks (+ distance) functions, which can't be cheaply computed without caching.

https://repo.mercurial-scm.org/hg/help/templating

We can also add revset function.

[Ghoughpteighbteau]

As a dirty hack to get something... sorta like the initial request, you could add this to you .bashrc:

alias jjd="jj describe -m \"\$(jj log -T 'local_bookmarks ++ \"\n\"' --no-graph -r \"heads(::@- & bookmarks())\") - \" --edit"

or if nushell is your main shell

alias jjd = jj describe -m $'(jj log -T "local_bookmarks ++ '\n'" --no-graph -r "heads(::@- & bookmarks())") - ' --edit

Maybe can be improved on? :/

[hneiva]

it's a good idea

[szabba]

#7422 lists least two other thing this would be nice for.