cli: basic jj gerrit send implementation

This implements the most basic workflow for submitting changes to Gerrit,
through a verb called 'send'. This verb is intended to be distinct from the word
'submit', which for Gerrit means 'merge a change into the repository.'

Given a list of revsets (specified by multiple `-r` options), this will parse
the footers of every commit, collect them, insert a `Change-Id` (if one doesn't
already exist), and then push them into the given remote.

Because the argument is a revset, you may submit entire trees of changes at
once, including multiple trees of independent changes, e.g.

    jj gerrit send -r foo:: -r baz::

There are many other improvements that can be applied on top of this, including
a ton of consistency and "does this make sense?" checks. However, it is flexible
and a good starting point, and you can in fact both submit and cycle reviews
with this interface.

Signed-off-by: Austin Seipp <[email protected]>

cli/src/commands/gerrit/mod.rs

@@ -0,0 +1,57 @@
+// Copyright 2024 The Jujutsu Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::fmt::Debug;
+
+use clap::Subcommand;
+
+use crate::cli_util::CommandHelper;
+use crate::command_error::CommandError;
+use crate::commands::gerrit;
+use crate::ui::Ui;
+
+/// Interact with Gerrit Code Review.
+#[derive(Subcommand, Clone, Debug)]
+pub enum GerritCommand {
+    /// Send changes to Gerrit for code review, or update existing changes.
+    ///
+    /// Sending in a set of revisions to Gerrit creates a single "change" for
+    /// each revision included in the revset. This change is then available for
+    /// review on your Gerrit instance.
+    ///
+    /// This command modifies each commit in the revset to include a `Change-Id`
+    /// footer in its commit message if one does not already exist. Note that
+    /// this ID is NOT compatible with jj IDs, and is Gerrit-specific.
+    ///
+    /// If a change already exists for a given revision (i.e. it contains the
+    /// same `Change-Id`), this command will update the contents of the existing
+    /// change to match.
+    ///
+    /// Note: this command takes 1-or-more revsets arguments, each of which can
+    /// resolve to multiple revisions; so you may post trees or ranges of
+    /// commits to Gerrit for review all at once.
+    Send(gerrit::send::SendArgs),
+}
+
+pub fn cmd_gerrit(
+    ui: &mut Ui,
+    command: &CommandHelper,
+    subcommand: &GerritCommand,
+) -> Result<(), CommandError> {
+    match subcommand {
+        GerritCommand::Send(review) => gerrit::send::cmd_send(ui, command, review),
+    }
+}
+
+mod send;