Issue warning if renaming branch with a remote tracking branch.

CHANGELOG.md

@@ -14,6 +14,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * New `jj op abandon` command is added to clean up the operation history. If GC
   is implemented, Git refs and commit objects can be compacted.
 
+* `jj branch rename` will now warn if the renamed branch has a remote branch, since
+  those will have to be manually renamed outside of `jj`.
+
 ### Fixed bugs
 
 

cli/src/commands/branch.rs

@@ -350,6 +350,19 @@ fn cmd_branch_rename(
         return Err(user_error(format!("Branch already exists: {new_branch}")));
     }
 
+    if view
+        .remote_branches_matching(
+            &StringPattern::exact(old_branch),
+            &StringPattern::everything(),
+        )
+        .any(|(_, remote_ref)| remote_ref.is_tracking())
+    {
+        writeln!(
+            ui.warning(),
+            "warning: Branch {old_branch} has remote branches which will not be renamed"
+        )?;
+    }
+
     let mut tx = workspace_command.start_transaction();
     tx.mut_repo()
         .set_local_branch_target(new_branch, ref_target);
@@ -363,6 +376,7 @@ fn cmd_branch_rename(
             make_branch_term(&[new_branch]),
         ),
     )?;
+
     Ok(())
 }
 

cli/tests/snapshots/test_branch_command__.snap

@@ -0,0 +1,5 @@
+---
+source: cli/tests/test_branch_command.rs
+expression: "\"moo\""
+---
+moo

cli/tests/test_branch_command.rs

@@ -195,20 +195,41 @@ fn test_branch_rename() {
     test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
     let repo_path = test_env.env_root().join("repo");
 
-    let stderr = test_env.jj_cmd_failure(&repo_path, &["branch", "rename", "foo", "bar"]);
+    // Set up remote
+    let git_repo_path = test_env.env_root().join("git-repo");
+    git2::Repository::init_bare(git_repo_path).unwrap();
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["git", "remote", "add", "origin", "../git-repo"],
+    );
+
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["branch", "rename", "bnoexist", "blocal"]);
     insta::assert_snapshot!(stderr, @r###"
-    Error: No such branch: foo
+    Error: No such branch: bnoexist
     "###);
 
-    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "foo"]);
-    let (_stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["branch", "rename", "foo", "bar"]);
+    test_env.jj_cmd_ok(&repo_path, &["describe", "-m=commit-0"]);
+    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "blocal"]);
+    let (_stdout, stderr) =
+        test_env.jj_cmd_ok(&repo_path, &["branch", "rename", "blocal", "blocal1"]);
     insta::assert_snapshot!(stderr, @"");
 
     test_env.jj_cmd_ok(&repo_path, &["new"]);
-    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "conflictfoo"]);
-    let stderr = test_env.jj_cmd_failure(&repo_path, &["branch", "rename", "bar", "conflictfoo"]);
+    test_env.jj_cmd_ok(&repo_path, &["describe", "-m=commit-1"]);
+    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "bexist"]);
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["branch", "rename", "blocal1", "bexist"]);
+    insta::assert_snapshot!(stderr, @r###"
+    Error: Branch already exists: bexist
+    "###);
+
+    test_env.jj_cmd_ok(&repo_path, &["new"]);
+    test_env.jj_cmd_ok(&repo_path, &["describe", "-m=commit-2"]);
+    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "bremote"]);
+    test_env.jj_cmd_ok(&repo_path, &["git", "push", "-b=bremote"]);
+    let (_stdout, stderr) =
+        test_env.jj_cmd_ok(&repo_path, &["branch", "rename", "bremote", "bremote2"]);
     insta::assert_snapshot!(stderr, @r###"
-    Error: Branch already exists: conflictfoo
+    warning: Branch bremote has remote branches which will not be renamed
     "###);
 }