stupid jj tricks

Given at JJ Con 2025. A survey of interesting revset aliases, templates, aliases, and other configuration to accomplish common (or not so common) tasks.

Transcript

1. André Arko | jjcon | September 28, 2025 stupid jj tricks revset aliases, templates, aliases, and other con fi guration
2. André Arko | jjcon | September 28, 2025 stupid jj tricks revset aliases, templates, aliases, and other con fi guration
3. André Arko andre.arko.net github.com/@indirect bsky.social/pro fi le/indirect.io
4. con fi guration
5. con fi guration scopes use work email in all work repos [[--scope]] --when.repositories = ["~/work"] [--scope.user] email = "me@work.domain"
6. con fi gure di ffi ng generate di ff s with di ff tastic [ui] diff-formatter = ["difft", “--color=always", “$left", "$right"]
7. con fi gure di ffi ng generate di ff s with delta [[--scope]] --when.commands = ["diff", "show"] [--scope.ui] pager = "delta" diff-formatter = ":git"
8. con fi gure di ff editing editor for jj split or jj squash -i [ui] diff-editor = "meld" # or vimdiff, vscode, etc
9. con fi gure con fl ict editor editor for jj resolve [ui] merge-editor = "meld" # or vimdiff, vscode, mergiraf
10. con fi gure con fl ict editor editor for jj resolve [merge-tools.filemerge] program = "open" edit-args = ["-a", "FileMerge", "-n", "-W", "--args", "-left", "$left", "-right", "$right", "-merge", "$output"] merge-args = ["-a", "FileMerge", "-n", "-W", "--args", "-left", "$left", "-right", "$right", "-ancestor", "$base", "-merge", "$output"]
11. con fi gure default command runs on just jj [ui] default-command = ["status"]
12. con fi gure default log revset used by jj log [revsets] log = "(trunk()..@):: | (trunk()..@)-"
13. templates try the builtins fi rst $ jj log -T | rg builtin_log - builtin_log_comfortable - builtin_log_compact - builtin_log_compact_full_description - builtin_log_detailed - builtin_log_oneline
14. template draft commit description pre fi lled in your editor on commit
15. template draft commit description pre fi lled in your editor on commit [templates] draft_commit_description = ''' concat( 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(), ) '''
16. template fragments used by the built-in templates
17. template fragments format_timestamp() [template-aliases] "format_timestamp(timestamp)" = "timestamp.utc()" # 2025-02-17 21:23:47.000 +00:00
18. template fragments format_timestamp() [template-aliases] "format_timestamp(timestamp)" = "timestamp.utc()" # 2025-02-17 21:23:47.000 +00:00 "format_timestamp(timestamp)" = "timestamp" # 2025-02-13 01:53:08.000 -08:00
19. template fragments format_timestamp() [template-aliases] "format_timestamp(timestamp)" = "timestamp.utc()" # 2025-02-17 21:23:47.000 +00:00 "format_timestamp(timestamp)" = "timestamp" # 2025-02-13 01:53:08.000 -08:00 "format_timestamp(timestamp)" = "timestamp.ago()" # 7 months ago
20. template fragments log_node [templates] log_node = 'if(self && !current_working_copy && !immutable && !conflict && in_branch(self), "◇", builtin_log_node)' [template-aliases] "in_branch(commit)" = 'commit.contained_in( "immutable_heads()..bookmarks()")'
21. template tricks description_body [template-aliases] description_body = ''' description.remove_prefix( description.first_line() ).trim_start() '''
22. template tricks valid json output log_json_stream = ''' "{" ++ "change_id".escape_json() ++ ": " ++ stringify(change_id).escape_json() ++ ", " ++ "author".escape_json() ++ ": " ++ stringify(author).escape_json() ++ "}\n" '''
23. template tricks valid json output
24. revsets
25. revsets whomst 'user(x)' = 'author(x) | committer(x)' 'mine()' = 'user("me@personal.domain") | user("me@domain")'
26. revsets whamst 'user(x)' = 'author(x) | committer(x)' 'mine()' = 'user("me@personal.domain") | user("me@domain")' 'wip()' = 'description(glob:"wip:*")' 'private()' = 'description(glob:"private:*")'
27. revsets stacks 'stack(x, n)' = 'ancestors( reachable(x, mutable() ), n)' 'stack(x)' = 'stack(x, 2)' 'stack()' = 'stack(@)'
28. revsets open 'stack(x, n)' = 'ancestors( reachable(x, mutable() ), n)' 'stack(x)' = 'stack(x, 2)' 'stack()' = 'stack(@)' 'open()' = 'stack(mine() | @, 1)'
29. revsets open 'stack(x, n)' = 'ancestors( reachable(x, mutable() ), n)' 'stack(x)' = 'stack(x, 2)' 'stack()' = 'stack(@)' 'open()' = 'stack(mine() | @, 1)' 'ready()' = 'open() ~ descendants( wip() | private() )'
30. revsets interesting 'uninterested()' = '::remote_bookmarks() | tags()' 'interested()' = 'mine() ~ uninterested()' 'open()' = ''' ancestors(interested(), 3) | tracked_remote_bookmarks() | ancestors(@, 3) '''
31. commands no, not aliases
32. commands jj absorb --help Move changes from a revision into the stack of mutable revisions This command splits changes in the source revision and moves each change to the closest mutable ancestor where the corresponding lines were modified last. If the destination revision cannot be determined unambiguously, the change will be left in the source revision. The source revision will be abandoned if all changes are absorbed into the destination revisions, and if the source revision has no description. The modification made by `jj absorb` can be reviewed by `jj op show -p`.
33. commands jj parallelize --help Parallelize revisions by making them siblings Running `jj parallelize 1::2` will transform the history like this: 3 | 3 2 / \ | -> 1 2 1 \ / | 0 0 The command effectively says "these revisions are actually independent", meaning that they should no longer be ancestors/descendants of each other. However, revisions outside the set that were previously ancestors of a revision in the set will remain ancestors of it. For example, revision 0 above remains an ancestor of both 1 and 2. Similarly, revisions outside the set that were previously descendants of a revision in the set will remain descendants of it. For example, revision 3 above remains a descendant of both 1 and 2.
34. commands jj fix [fix.tools.black] command = ["/usr/bin/black", "-", "--stdin-filename=$path"] patterns = ["glob:'**/*.py'"]
35. aliases jj tug tug = ["bookmark", "move", "--from", "heads(::@- & bookmarks())", "--to", "@-"]
36. aliases jj tug [revset-aliases] 'closest_pushable(to)' = 'heads(::to & mutable() & ~description(exact:"") & (~empty() | merges()))' [aliases] tug = 'bookmark move --from "heads(::@ & bookmarks())" --to "closest_pushable(@)"'
37. aliases jj tug $1 tug = ["util", "exec", "--", "sh", "-c", """ if [ "x$1" = "x" ]; then jj bookmark move --from "closest_bookmark(@)" --to "closest_pushable(@)" else jj bookmark move --to "closest_pushable(@)" "$@" fi """, ""]
38. aliases jj pr pr = ["util", "exec", "--", "bash", "-c", """ gh pr create --head $( jj log -r 'closest_bookmark(@)' -T 'bookmarks' --no-graph | cut -d ' ' -f 1 ) """]
39. aliases jj init init = ["util", "exec", "--", "bash", "-c", """ jj git init --colocate # only track origin branches, no upstream or other jj bookmark track 'glob:*@origin' """]
40. aliases jj pull pull = ["util", "exec", "--", "bash", "-c", """ closest="$(jj log -r 'closest_bookmark(@)' -n 1 -T 'bookmarks' --no-graph | cut -d ' ' -f 1)" closest="${closest%\\*}" jj git fetch jj log -n 1 -r "${closest}" 2>&1 > /dev/null && jj rebase -d "${closest}" || jj rebase -d 'trunk()' jj log -r 'stack()' """]
41. aliases jj push push = ["util", "exec", "--", "bash", "-c", """ tuggable="$(jj log -r 'closest_bookmark(@)..closest_pushable(@)' -T '"n"' --no-graph)" [[ -n "$tuggable" ]] && jj tug pushable="$(jj log -r 'remote_bookmarks(remote=origin)..@' -T 'bookmarks' --no-graph)" [[ -n "$pushable" ]] && jj git push || echo "Nothing to push." closest="$(jj log -r 'closest_bookmark(@)' -n 1 -T 'bookmarks' --no-graph | cut -d ' ' -f 1)" closest="${closest%\\*}" tracked="$(jj bookmark list -r ${closest} -t -T 'if(remote == "origin", name)')" [[ "$tracked" == "$closest" ]] || jj bookmark track "${closest}@origin" """]
42. combo tricks the cursed of the cursed
44. combo tricks jj ll [revset-aliases] 'recent_work' = 'ancestors(visible_heads(), 3) & mutable()' [template-aliases] log_with_files = ''' concat([default jj log template here] ++ "\n", if(self.contained_in("recent_work"), diff.summary()) '''
45. combo tricks jj z z = ["fuzzy_bookmark"] za = ["bookmark", "list", "-a"] fuzzy_bookmark = ["util", "exec", "--", "sh", "-c", """ if [ "x$1" = "x" ]; then jj bookmark list else jj bookmark list -a -T 'separate("@", name, remote) ++ "\n"' 2> /dev/null | sort | uniq | fzf -f "$1" | head -n1 | xargs jj new fi """, ""]
46. shell prompt tricks I couldn't squeeze them in :( https://andre.arko.net/2025/06/20/a-jj-prompt-for-powerlevel10k/
47. acknowledgments & thanks every jj contributor config posters: @martinvonz, @thoughtpolice, @pksunkara, @scott2000, @avamsi, @simonmichael, @sunshowers bugged me into trying jj: @steveklabnik, @endsofthreads thank you so much, to all of you
48. questions? 󰇮 andre@arko.net  @indirect  @indirect.io