The original idea was similar to Mercurial's "topo" sorting, but it was bad
at handling merge-heavy history. In order to render merges of topic branches
nicely, we need to prioritize branches at merge point, not at fork point.
OTOH, we do also want to place unmerged branches as close to the fork point
as possible. This commit implements the former requirement, and the latter
will be addressed by the next commit.
I think this is similar to Git's sorting logic described in the following blog
post. In our case, the in-degree walk can be dumb since topological order is
guaranteed by the index. We keep HashSet<CommitId> instead of an in-degree
integer value, which will be used in the next commit to resolve new heads as
late as possible.
https://github.blog/2022-08-30-gits-database-internals-ii-commit-history-queries/#topological-sorting
Compared to Sapling's beautify_graph(), this is lazy, and can roughly preserve
the index (or chronological) order. I tried beautify_graph() with prioritizing
the @ commit, but the result seemed too aggressively reordered. Perhaps, for
more complex history, beautify_graph() would produce a better result. For my
wip branches (~30 branches, a couple of commits per branch), this works pretty
well.
#242
On "jj checkout", description of the working-copy commit is empty, and the
working-copy parent provides more information. It might be a bit verbose to
print parent summary on every history rewriting, but I think that's okay.
@joyously found `o` confusing because it's a valid change id prefix. I
don't have much preference, but `●` seems fine. The "ascii",
"ascii-large", and "legacy" graph styles still use "o".
I didn't change `@` since it seems useful to have that match the
symbol used on the CLI. I don't think we want to have users do
something like `jj co ◎-`.
This eliminates ambiguous parsing between "func()" and "expr ()".
I chose "++" as template concatenation operator in case we want to add
bit-wise negate operator. It's also easier to find/replace than "~".
This allows us to use "if(description,)" to test empty description. And
I think this change is unavoidable if we want to add support for commit
template.
Otherwise the description set by -m would differ from the one set by editor.
This fixes test_describe() which says "make no changes", but previously "\n"
would be added by the second "jj describe".
As you can see, almost all hashes change in CLI tests. This means in-flight
PRs will need to be rebased to update insta snapshots.
Description text could be normalized by CommitBuilder, but the caller would
have to normalize it beforehand to compare with the current description, so
we would need an explicit function anyway. Another idea is to add a newtype
that represents a normalized description, and make CommitBuilder require it.
Commit::description() will return &Description in place of &str to ensure
that commit.description() == raw_str wouldn't compile.
Git CLI provides --cleanup=<mode> option to switch normalization rules, but
I don't think we'll need such feature.
Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
In the test case `test_branch_mutually_exclusive_actions`, we weren't actually testing anything useful, because the interface has since changed to use subcommands instead of options. The test has been deleted in this commit, and `TestEnvironment::jj_cmd_cli_error` has been changed to return a `#[must_use]` `String` representing stderr. I also added `#[must_use]` to `TestEnvironment::jj_cmd_failure` while I was here.
`jj merge` just creates an empty change, which is practically the same
as `jj new`. The main difference is that the former requires more than
one argument and the latter requires at most one argument. It seems
cleaner to generalize them and make them aliases. This patch starts
doing that by making `jj new` accept more than one argument.
Instead of having `jj merge` be exactly an alias for `jj new`, we may
want to make it a thin wrapper that just checks that more than one
argument was given. That would probably be less confusing to users who
run `jj merge` without arguments to see what it does.
We should probably make `jj checkout` also be an alias for `jj new`,
but that will have to wait until we have removed support for open
commits (since `jj checkout` still has logic for dealing with open
commits).
