Report what operation has been undone in jj op undo

CHANGELOG.md

@@ -56,6 +56,8 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   allows to set a name for the remote instead of using the default
   `origin`.
 
+* `jj op undo` now reports information on the operation that has been undone.
+
 ### Fixed bugs
 
  * Fixed panic when parsing invalid conflict markers of a particular form.

cli/src/cli_util.rs

@@ -725,6 +725,7 @@ pub struct WorkspaceCommandHelper {
     env: WorkspaceCommandEnvironment,
     // TODO: Parsed template can be cached if it doesn't capture 'repo lifetime
     commit_summary_template_text: String,
+    op_summary_template_text: String,
     may_update_working_copy: bool,
     working_copy_shared_with_git: bool,
 }
@@ -740,6 +741,7 @@ impl WorkspaceCommandHelper {
         let settings = env.settings();
         let commit_summary_template_text =
             settings.config().get_string("templates.commit_summary")?;
+        let op_summary_template_text = settings.config().get_string("templates.op_summary")?;
         let may_update_working_copy =
             loaded_at_head && !env.command.global_args().ignore_working_copy;
         let working_copy_shared_with_git = is_colocated_git_workspace(&workspace, &repo);
@@ -748,11 +750,13 @@ impl WorkspaceCommandHelper {
             user_repo: ReadonlyUserRepo::new(repo),
             env,
             commit_summary_template_text,
+            op_summary_template_text,
             may_update_working_copy,
             working_copy_shared_with_git,
         };
         // Parse commit_summary template early to report error before starting
         // mutable operation.
+        helper.parse_operation_template(&helper.op_summary_template_text)?;
         helper.parse_commit_template(&helper.commit_summary_template_text)?;
         helper.parse_commit_template(SHORT_CHANGE_ID_TEMPLATE_TEXT)?;
         Ok(helper)
@@ -1288,6 +1292,19 @@ impl WorkspaceCommandHelper {
         )
     }
 
+    /// Parses commit template into evaluation tree.
+    pub fn parse_operation_template(
+        &self,
+        template_text: &str,
+    ) -> TemplateParseResult<TemplateRenderer<'_, Operation>> {
+        let language = self.operation_template_language();
+        self.parse_template(
+            &language,
+            template_text,
+            OperationTemplateLanguage::wrap_operation,
+        )
+    }
+
     /// Creates commit template language environment for this workspace.
     pub fn commit_template_language(&self) -> CommitTemplateLanguage<'_> {
         self.env
@@ -1309,6 +1326,12 @@ impl WorkspaceCommandHelper {
             .expect("parse error should be confined by WorkspaceCommandHelper::new()")
     }
 
+    /// Template for one-line summary of an operation.
+    pub fn operation_summary_template(&self) -> TemplateRenderer<'_, Operation> {
+        self.parse_operation_template(&self.op_summary_template_text)
+            .expect("parse error should be confined by WorkspaceCommandHelper::new()")
+    }
+
     pub fn short_change_id_template(&self) -> TemplateRenderer<'_, Commit> {
         self.parse_commit_template(SHORT_CHANGE_ID_TEMPLATE_TEXT)
             .expect("parse error should be confined by WorkspaceCommandHelper::new()")

cli/src/commands/operation/diff.rs

@@ -36,7 +36,6 @@ use jj_lib::revset;
 use jj_lib::revset::RevsetIteratorExt as _;
 
 use crate::cli_util::short_change_hash;
-use crate::cli_util::short_operation_hash;
 use crate::cli_util::CommandHelper;
 use crate::cli_util::LogContentFormat;
 use crate::command_error::CommandError;
@@ -123,42 +122,15 @@ pub fn cmd_op_diff(
         workspace_env.parse_template(&language, &text, CommitTemplateLanguage::wrap_commit)?
     };
 
+    let op_summary_template = workspace_command.operation_summary_template();
     ui.request_pager();
     let mut formatter = ui.stdout_formatter();
     formatter.with_label("op_log", |formatter| {
         write!(formatter, "From operation ")?;
-        write!(
-            formatter.labeled("id"),
-            "{}",
-            short_operation_hash(from_op.id()),
-        )?;
-        write!(formatter, ": ")?;
-        write!(
-            formatter.labeled("description"),
-            "{}",
-            if from_op.id() == from_op.op_store().root_operation_id() {
-                "root()"
-            } else {
-                &from_op.metadata().description
-            }
-        )?;
+        op_summary_template.format(&from_op, &mut *formatter)?;
         writeln!(formatter)?;
         write!(formatter, "  To operation ")?;
-        write!(
-            formatter.labeled("id"),
-            "{}",
-            short_operation_hash(to_op.id()),
-        )?;
-        write!(formatter, ": ")?;
-        write!(
-            formatter.labeled("description"),
-            "{}",
-            if to_op.id() == to_op.op_store().root_operation_id() {
-                "root()"
-            } else {
-                &to_op.metadata().description
-            }
-        )?;
+        op_summary_template.format(&to_op, &mut *formatter)?;
         writeln!(formatter)
     })?;
 

cli/src/commands/operation/undo.rs

@@ -70,5 +70,12 @@ pub fn cmd_op_undo(
     tx.repo_mut().set_view(new_view);
     tx.finish(ui, format!("undo operation {}", bad_op.id().hex()))?;
 
+    if let Some(mut formatter) = ui.status_formatter() {
+        write!(formatter, "Undid operation ")?;
+        let template = workspace_command.operation_summary_template();
+        template.format(&bad_op, &mut *formatter)?;
+        writeln!(formatter)?;
+    }
+
     Ok(())
 }

cli/src/config/templates.toml

@@ -41,6 +41,13 @@ tag_list = '''
 label("tag", name) ++ format_ref_targets(self) ++ "\n"
 '''
 
+op_summary = '''
+if(root,
+  separate(" ", self.id().short(), label("root", "root()")),
+  separate(" ", self.id().short(), format_time_range(self.time()), self.description().first_line())
+)
+'''
+
 [template-aliases]
 builtin_log_oneline = '''
 if(root,

cli/tests/test_duplicate_command.rs

@@ -75,7 +75,9 @@ fn test_duplicate() {
 
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["undo"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Undid operation c4b0b2a977fe 2001-02-03 04:05:17.000 +07:00 - 2001-02-03 04:05:17.000 +07:00 duplicate 1 commit(s)
+    "#);
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["duplicate" /* duplicates `c` */]);
     insta::assert_snapshot!(stdout, @"");
     insta::assert_snapshot!(stderr, @r###"
@@ -277,7 +279,9 @@ fn test_undo_after_duplicate() {
 
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["undo"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Undid operation 5a2bcfcdd78b 2001-02-03 04:05:11.000 +07:00 - 2001-02-03 04:05:11.000 +07:00 duplicate 1 commit(s)
+    "#);
     insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
     @  2443ea76b0b1   a
     ◆  000000000000

cli/tests/test_evolog_command.rs

@@ -327,7 +327,7 @@ fn test_evolog_with_no_template() {
     let repo_path = test_env.env_root().join("repo");
 
     let stderr = test_env.jj_cmd_cli_error(&repo_path, &["evolog", "-T"]);
-    insta::assert_snapshot!(stderr, @r###"
+    insta::assert_snapshot!(stderr, @r#"
     error: a value is required for '--template <TEMPLATE>' but none was supplied
 
     For more information, try '--help'.
@@ -346,5 +346,5 @@ fn test_evolog_with_no_template() {
     - description_placeholder
     - email_placeholder
     - name_placeholder
-    "###);
+    "#);
 }

cli/tests/test_git_colocated.rs

@@ -756,10 +756,11 @@ fn test_git_colocated_undo_head_move() {
     // HEAD should be moved back
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["undo"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @r###"
+    insta::assert_snapshot!(stderr, @r#"
     Working copy now at: royxmykx eb08b363 (empty) (no description set)
     Parent commit      : qpvuntsm 230dd059 (empty) (no description set)
-    "###);
+    Undid operation 951a1c249028 2001-02-03 04:05:13.000 +07:00 - 2001-02-03 04:05:13.000 +07:00 new empty commit
+    "#);
     insta::assert_snapshot!(
         git_repo.head().unwrap().target().unwrap().to_string(),
         @"230dd059e1b059aefc0da06a2e5a7dbf22362f22");

cli/tests/test_git_fetch.rs

@@ -845,7 +845,9 @@ fn test_git_fetch_undo() {
     "###);
     let (stdout, stderr) = test_env.jj_cmd_ok(&target_jj_repo_path, &["undo"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Undid operation bbebbf6a6ebe 2001-02-03 04:05:18.000 +07:00 - 2001-02-03 04:05:18.000 +07:00 fetch from git remote(s) origin
+    "#);
     // The undo works as expected
     insta::assert_snapshot!(get_log_output(&test_env, &target_jj_repo_path), @r###"
     @  230dd059e1b0

cli/tests/test_git_import_export.rs

@@ -100,7 +100,9 @@ fn test_git_export_undo() {
     // bookmark is. This is the same as remote-tracking bookmarks.
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["op", "undo"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Undid operation 1bc51ad79d63 2001-02-03 04:05:10.000 +07:00 - 2001-02-03 04:05:10.000 +07:00 export git refs
+    "#);
     insta::assert_debug_snapshot!(get_git_repo_refs(&git_repo), @r###"
     [
         (

cli/tests/test_log_command.rs

@@ -36,7 +36,7 @@ fn test_log_with_no_template() {
     let repo_path = test_env.env_root().join("repo");
 
     let stderr = test_env.jj_cmd_cli_error(&repo_path, &["log", "-T"]);
-    insta::assert_snapshot!(stderr, @r###"
+    insta::assert_snapshot!(stderr, @r#"
     error: a value is required for '--template <TEMPLATE>' but none was supplied
 
     For more information, try '--help'.
@@ -55,7 +55,7 @@ fn test_log_with_no_template() {
     - description_placeholder
     - email_placeholder
     - name_placeholder
-    "###);
+    "#);
 }
 
 #[test]