cli: teach jj split to include all specified paths in first commit

CHANGELOG.md

@@ -16,6 +16,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   mode). For example, use `jj move --to @-- foo` to move the changes to file
   (or directory) `foo` in the working copy to the grandparent commit.
 
+* `jj split` now lets you specify on the CLI which paths to include in the first
+  commit. The interactive diff-editing is not started when you do that.
+
 * The `$JJ_CONFIG` environment variable can now point to a directory. If it
   does, all files in the directory will be read, in alphabetical order.
 

src/commands.rs

@@ -1366,6 +1366,8 @@ struct SplitArgs {
     /// The revision to split
     #[clap(long, short, default_value = "@")]
     revision: String,
+    /// Put these paths in the first commit and don't run the diff editor
+    paths: Vec<String>,
 }
 
 /// Merge work from multiple branches
@@ -3497,7 +3499,14 @@ any changes, then the operation will be aborted.
 ",
         short_commit_description(&commit)
     );
-    let tree_id = workspace_command.edit_diff(&base_tree, &commit.tree(), &instructions)?;
+    let tree_id = workspace_command.select_diff(
+        ui,
+        &base_tree,
+        &commit.tree(),
+        &instructions,
+        args.paths.is_empty(),
+        &args.paths,
+    )?;
     if &tree_id == commit.tree().id() {
         ui.write("Nothing changed.\n")?;
     } else {

tests/test_split_command.rs

@@ -0,0 +1,59 @@
+// 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 crate::common::TestEnvironment;
+
+pub mod common;
+
+#[test]
+fn test_split() {
+    let mut test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    std::fs::write(repo_path.join("file1"), "foo").unwrap();
+    std::fs::write(repo_path.join("file2"), "foo").unwrap();
+    std::fs::write(repo_path.join("file3"), "foo").unwrap();
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "commit_id.short()"]);
+    insta::assert_snapshot!(stdout, @r###"
+    @ 9d08ea8cac40
+    o 000000000000
+    "###);
+
+    let edit_script = test_env.set_up_fake_editor();
+    std::fs::write(edit_script, "").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["split", "file2"]);
+    insta::assert_snapshot!(stdout, @r###"
+    First part: 5eebce1de3b0 
+    Second part: 45833353d94e 
+    Working copy now at: 45833353d94e 
+    "###);
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "commit_id.short()"]);
+    insta::assert_snapshot!(stdout, @r###"
+    @ 45833353d94e
+    o 5eebce1de3b0
+    o 000000000000
+    "###);
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s", "-r", "@-"]);
+    insta::assert_snapshot!(stdout, @"A file2
+");
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s"]);
+    insta::assert_snapshot!(stdout, @r###"
+    A file1
+    A file3
+    "###);
+}