jj show can almost mimic jj status

[Zoybean]

I'm on a bit of an adventure making a jj interface in emacs, currently using the cli rather than the libs as it's easier (for now) not to have to use FFI. I was trying to parse the output of jj status when I realised there's a few cases (with filenames containing newline characters) where the output is ambiguous. I found a solution in jj show, where a clever template can supply almost all the information in jj status.

so far, the only significant differences in parity that I'm aware of, are:

• I cannot count the sides of a file conflict
• I can only show ref conflicts for the current commit, not the whole repo. but I can probably just call jj bookmark list -c for that.

of course I'd have to look at the rust source to be sure I havent missed something, but it was a fun exercise if nothing else.

so the invocation jj show --no-patch -T "$THIS_TEMPLATE" produces output that almost 1:1 matches jj status. i'll rework it later to escape filenames etc as needed for my purposes.

here's the template (yes, it's a lot) that mimics jj status:

separate("\n",
    "Working copy changes:",
    self.diff()
        .files()
        .map(|f|
              f.status()
              ++ ": "
              ++ separate(" -> ",
                  f.target().path(),
                  f.source().path()))
        .join("\n"),
    separate(" ",
        "Working copy (@) :",
        self.change_id().shortest(8) ++ if (self.divergent(), "??"),
        self.commit_id().shortest(8),
        surround("", " |",
            separate(" ",
                self.bookmarks()
                    .map(|r|
                          r.name()
                          ++ surround(
                              "@", "", r.remote())
                          ++ if (r.conflict(),
                              "??"))
                    .join(" "),
                self.tags()
                    .map(|r| r.name() ++ if (r.conflict(), "??"))
                    .join(" "))),
        if (self.conflict(), "(conflict)"),
        if (self.empty(), "(empty)"),
        coalesce(self.description().first_line(), "(no description set)")),
    self.parents()
        .map(|p|
              separate(" ",
                  "Parent commit (@-):",
                  p.change_id().shortest(8) ++ if (p.divergent(), "??"),
                  p.commit_id().shortest(8),
                  surround("", " |",
                      separate(" ",
                          p.bookmarks()
                              .map(|r| r.name()
                                    ++ surround("@", "", r.remote())
                                    ++ if (r.conflict(), "??"))
                              .join(" "),
                          p.tags()
                              .map(|r| r.name() ++ if (r.conflict(), "??"))
                              .join(" "))),
                  if (p.conflict(), "(conflict)"),
                  if (p.empty(), "(empty)"),
                  coalesce(p.description().first_line(), "(no description set)")))
        .join("\n"),
    if (self.conflict(),
        "Warning: There are unresolved conflicts at these paths:\n"
        ++ self
            .files()
            .filter(|f| f.conflict())
            .map(|f| f.path() ++ " ??-sided conflict")
            .join("\n")),
    surround("Warning: These bookmarks have conflicts:\n", "",
        self.bookmarks()
            .filter(|b| b.conflict())
            .map(|b| b.name())
            .join("\n")))

[Zoybean]

not sure whether this is more of an idea (to expose conflict counts in TreeEntry) or a show-and-tell of this cursed template, but for now I've labelled it an idea.