cli: add commit as its own command (not an alias for close)

It seems very likely that we're going to remove support for open
commits, but it's still useful to have a `commit` command that lets
the user enter a description and starts a new change. Calling it
`commit` seems good to make the transition from other VCSs simpler.

CHANGELOG.md

@@ -13,6 +13,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `committer(needle)`, `merges()` revsets. Use `x & description(needle)`
   instead.
 
+* `jj commit` is now a separate command from `jj close` (which is deprecated).
+  The behavior has changed slightly. It now always asks for a description, even
+  if there already was a description set. It now also only works on the
+  working-copy commit (there's no `-r` argument).
+
 ### New features
 
 * The new `jj git remote rename` command allows git remotes to be renamed

src/commands.rs

@@ -78,6 +78,7 @@ enum Commands {
     Obslog(ObslogArgs),
     Interdiff(InterdiffArgs),
     Describe(DescribeArgs),
+    Commit(CommitArgs),
     Close(CloseArgs),
     Open(OpenArgs),
     Duplicate(DuplicateArgs),
@@ -349,12 +350,21 @@ struct DescribeArgs {
     stdin: bool,
 }
 
+/// Update the description and create a new change on top.
+#[derive(clap::Args, Clone, Debug)]
+#[command(hide = true)]
+struct CommitArgs {
+    /// The change description to use (don't open editor)
+    #[arg(long, short)]
+    message: Option<String>,
+}
+
 /// Mark a revision closed
 ///
 /// For information about open/closed revisions, see
 /// https://github.com/martinvonz/jj/blob/main/docs/working-copy.md.
 #[derive(clap::Args, Clone, Debug)]
-#[command(visible_alias = "commit", hide = true)]
+#[command(hide = true)]
 struct CloseArgs {
     /// The revision to close
     #[arg(default_value = "@")]
@@ -2438,6 +2448,45 @@ fn cmd_describe(
     Ok(())
 }
 
+fn cmd_commit(ui: &mut Ui, command: &CommandHelper, args: &CommitArgs) -> Result<(), CommandError> {
+    let mut workspace_command = command.workspace_helper(ui)?;
+
+    let commit_id = workspace_command
+        .repo()
+        .view()
+        .get_wc_commit_id(&workspace_command.workspace_id())
+        .ok_or_else(|| UserError("This command requires a working copy".to_string()))?;
+    let commit = workspace_command.repo().store().get_commit(commit_id)?;
+
+    let mut commit_builder =
+        CommitBuilder::for_rewrite_from(ui.settings(), &commit).set_open(false);
+    let description = if let Some(message) = &args.message {
+        message.to_string()
+    } else {
+        edit_description(ui, workspace_command.repo(), commit.description())?
+    };
+    commit_builder = commit_builder.set_description(description);
+    let mut tx = workspace_command.start_transaction(&format!("commit {}", commit.id().hex()));
+    let new_commit = commit_builder.write_to_repo(tx.mut_repo());
+    let workspace_ids = tx
+        .mut_repo()
+        .view()
+        .workspaces_for_wc_commit_id(commit.id());
+    if !workspace_ids.is_empty() {
+        let new_checkout = CommitBuilder::for_open_commit(
+            ui.settings(),
+            new_commit.id().clone(),
+            new_commit.tree_id().clone(),
+        )
+        .write_to_repo(tx.mut_repo());
+        for workspace_id in workspace_ids {
+            tx.mut_repo().edit(workspace_id, &new_checkout).unwrap();
+        }
+    }
+    workspace_command.finish_transaction(ui, tx)?;
+    Ok(())
+}
+
 fn cmd_open(ui: &mut Ui, command: &CommandHelper, args: &OpenArgs) -> Result<(), CommandError> {
     let mut workspace_command = command.workspace_helper(ui)?;
     let commit = workspace_command.resolve_single_rev(&args.revision)?;
@@ -4527,6 +4576,7 @@ pub fn run_command(
         Commands::Interdiff(sub_args) => cmd_interdiff(ui, command_helper, sub_args),
         Commands::Obslog(sub_args) => cmd_obslog(ui, command_helper, sub_args),
         Commands::Describe(sub_args) => cmd_describe(ui, command_helper, sub_args),
+        Commands::Commit(sub_args) => cmd_commit(ui, command_helper, sub_args),
         Commands::Close(sub_args) => cmd_close(ui, command_helper, sub_args),
         Commands::Open(sub_args) => cmd_open(ui, command_helper, sub_args),
         Commands::Duplicate(sub_args) => cmd_duplicate(ui, command_helper, sub_args),

tests/test_commit_command.rs

@@ -0,0 +1,78 @@
+// Copyright 2022 Google LLC
+//
+// 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::path::Path;
+
+use crate::common::TestEnvironment;
+
+pub mod common;
+
+#[test]
+fn test_commit_with_description_from_cli() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let workspace_path = test_env.env_root().join("repo");
+
+    // Description applies to the current working-copy (not the new one)
+    test_env.jj_cmd_success(&workspace_path, &["commit", "-m=first"]);
+    insta::assert_snapshot!(get_log_output(&test_env, &workspace_path), @r###"
+    @ 69e88fe3e63b (no description set)
+    o 85a1e2839620 first
+    o 000000000000 (no description set)
+    "###);
+}
+
+#[test]
+fn test_commit_with_editor() {
+    let mut test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let workspace_path = test_env.env_root().join("repo");
+
+    // Check that the text file gets initialized with the current description and
+    // set a new one
+    test_env.jj_cmd_success(&workspace_path, &["describe", "-m=initial"]);
+    let edit_script = test_env.set_up_fake_editor();
+    std::fs::write(
+        &edit_script,
+        "expect
+initial
+JJ: Lines starting with \"JJ: \" (like this one) will be removed.
+\0write
+modified",
+    )
+    .unwrap();
+    test_env.jj_cmd_success(&workspace_path, &["commit"]);
+    insta::assert_snapshot!(get_log_output(&test_env, &workspace_path), @r###"
+    @ 3ea3453a773f (no description set)
+    o 792a60936c42 modified
+    o 000000000000 (no description set)
+    "###);
+}
+
+#[test]
+fn test_commit_without_working_copy() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let workspace_path = test_env.env_root().join("repo");
+
+    test_env.jj_cmd_success(&workspace_path, &["workspace", "forget"]);
+    let stderr = test_env.jj_cmd_failure(&workspace_path, &["commit", "-m=first"]);
+    insta::assert_snapshot!(stderr, @r###"
+    Error: This command requires a working copy
+    "###);
+}
+
+fn get_log_output(test_env: &TestEnvironment, cwd: &Path) -> String {
+    test_env.jj_cmd_success(cwd, &["log", "-T", r#"commit_id.short() " " description"#])
+}