fish-shell/share/functions/fish_jj_prompt.fish

function fish_jj_prompt
    # If jj isn't installed, there's nothing we can do
    # Return 1 so the calling prompt can deal with it
    if not command -sq jj
        return 1
    end
    set -l info "$(
        jj log 2>/dev/null --no-graph --ignore-working-copy --color=always --revisions @ \
            --template '
                separate(" ",
                    bookmarks,
                    tags,
                    if(conflict, label("conflict", "×")),
                    if(empty, label("empty", "(empty)"))
                )
            '
    )"
    or return 1
    if test -n "$info"
        printf ' %s' $info
    end
end