backout: add initial tests

cli/tests/runner.rs

@@ -12,6 +12,7 @@ mod test_abandon_command;
 mod test_acls;
 mod test_advance_branches;
 mod test_alias;
+mod test_backout_command;
 mod test_branch_command;
 mod test_builtin_aliases;
 mod test_checkout;

cli/tests/test_backout_command.rs

@@ -0,0 +1,82 @@
+// 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::path::Path;
+
+use crate::common::TestEnvironment;
+
+fn create_commit(test_env: &TestEnvironment, repo_path: &Path, name: &str, parents: &[&str]) {
+    if parents.is_empty() {
+        test_env.jj_cmd_ok(repo_path, &["new", "root()", "-m", name]);
+    } else {
+        let mut args = vec!["new", "-m", name];
+        args.extend(parents);
+        test_env.jj_cmd_ok(repo_path, &args);
+    }
+    std::fs::write(repo_path.join(name), format!("{name}\n")).unwrap();
+    test_env.jj_cmd_ok(repo_path, &["branch", "create", name]);
+}
+
+#[test]
+fn test_backout() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    create_commit(&test_env, &repo_path, "a", &[]);
+    // Test the setup
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    @  2443ea76b0b1 a
+    ◉  000000000000
+    "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s"]);
+    insta::assert_snapshot!(stdout, @r###"
+    A a
+    "###);
+
+    // Backout the commit
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["backout", "-r", "@"]);
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    ◉  8fe4e9345020 backout of commit 2443ea76b0b1c531326908326aab7020abab8e6c
+    @  2443ea76b0b1 a
+    ◉  000000000000
+    "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s", "-r", "@+"]);
+    insta::assert_snapshot!(stdout, @r###"
+    D a
+    "###);
+
+    // Backout the new backed-out commit
+    test_env.jj_cmd_ok(&repo_path, &["edit", "@+"]);
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["backout", "-r", "@"]);
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
+    ◉  46f192066e5e backout of commit 8fe4e93450209a70a6b9cd9af612e86634fd31fd
+    @  8fe4e9345020 backout of commit 2443ea76b0b1c531326908326aab7020abab8e6c
+    ◉  2443ea76b0b1 a
+    ◉  000000000000
+    "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s", "-r", "@+"]);
+    insta::assert_snapshot!(stdout, @r###"
+    A a
+    "###);
+}
+
+fn get_log_output(test_env: &TestEnvironment, cwd: &Path) -> String {
+    let template = r#"commit_id.short() ++ " " ++ description"#;
+    test_env.jj_cmd_success(cwd, &["log", "-T", template])
+}