FR: Support passing template to jj show command

[zummenix]

Is your feature request related to a problem? Please describe.

I'd like to setup my shell prompt to print current state of a change – basic info like change id, empty or not, maybe description and a branch

Describe the solution you'd like

I'd like to pass a custom template from my jj config to jj show, for example ex: jj show -T prompt_show_oneline

Describe alternatives you've considered

One alternative is to use jj log -T prompt_show_oneline | head -n1 but it prints leading symbols of a graph (dots and @) that I don't need in this case.

Additional context

–

[martinvonz]

but it prints leading symbols of a graph

There's --no-graph :) (But that doesn't mean that we shouldn't support templating in jj show.)

[zummenix]

There's --no-graph

Thank you! I haven't thought about it :)

I managed it to work using jj log --no-graph --limit 1 -r ..@ -T prompt_show_oneline

[necauqua]

Just in case keep in mind that that means every prompt invocation also snapshots the repo, which sometimes could be bad, potentially - say you have a gigabyte of logs temporarily or something, although that one would be caught by the heuristic - and a bunch of operations for all the snapshots too

For truly lightweight prompt (that will show that repo is stale until you run some jj command), a non-snapshotting status/diff are needed (there's a FR I made for that, hard to look up on mobile while typing this)

[zummenix]

For truly lightweight prompt (that will show that repo is stale until you run some jj command), a non-snapshotting status/diff are needed (there's a FR I made for that, hard to look up on mobile while typing this)

@necauqua Most likely this one: #2562