cli: make jj branch track show conflicts

CHANGELOG.md

@@ -29,6 +29,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * `ui.color = "debug"` prints active labels alongside the regular colored output.
 
+* `jj branch track` now show conflicts if there are some.
+
 ### Fixed bugs
 
 * When the working copy commit becomes immutable, a new one is automatically created on top of it 

cli/src/commands/branch.rs

@@ -18,7 +18,7 @@ use std::io::Write as _;
 
 use clap::builder::NonEmptyStringValueParser;
 use itertools::Itertools;
-use jj_lib::git;
+use jj_lib::git::{self, REMOTE_NAME_FOR_LOCAL_GIT_REPO};
 use jj_lib::object_id::ObjectId;
 use jj_lib::op_store::{RefTarget, RemoteRef};
 use jj_lib::repo::Repo;
@@ -569,6 +569,52 @@ fn cmd_branch_track(
             names.len()
         )?;
     }
+
+    //show conflicted branches if there are some
+    let template = {
+        let language = workspace_command.commit_template_language()?;
+        let text = command
+            .settings()
+            .config()
+            .get::<String>("templates.branch_list")?;
+        workspace_command
+            .parse_template(&language, &text, CommitTemplateLanguage::wrap_ref_name)?
+            .labeled("branch_list")
+    };
+
+    ui.request_pager();
+    if let Some(mut formatter) = ui.status_formatter() {
+        let branches_to_list =
+            workspace_command
+                .repo()
+                .view()
+                .branches()
+                .filter(|(name, target)| {
+                    names
+                        .iter()
+                        .map(|n| n.branch.clone())
+                        .contains(&name.to_string())
+                        && (target.local_target.has_conflict())
+                });
+        for (name, branch_target) in branches_to_list {
+            let local_target = branch_target.local_target;
+            let ref_name = RefName::local(
+                name,
+                local_target.clone(),
+                branch_target.remote_refs.iter().map(|x| x.1),
+            );
+            template.format(&ref_name, formatter.as_mut())?;
+
+            for (remote_name, remote_ref) in branch_target.remote_refs {
+                //shall we show @git remote ?
+                if remote_name == REMOTE_NAME_FOR_LOCAL_GIT_REPO {
+                    continue;
+                }
+                let ref_name = RefName::remote(name, remote_name, remote_ref.clone(), local_target);
+                template.format(&ref_name, formatter.as_mut())?;
+            }
+        }
+    }
     Ok(())
 }
 

cli/tests/test_branch_command.rs

@@ -826,7 +826,34 @@ fn test_branch_track_untrack() {
     ◉   000000000000
     "###);
 }
+#[test]
+fn test_branch_track_conflict() {
+    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");
 
+    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"],
+    );
+    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "main"]);
+    test_env.jj_cmd_ok(&repo_path, &["describe", "-m", "a"]);
+    test_env.jj_cmd_ok(&repo_path, &["git", "push", "-b", "main"]);
+    test_env.jj_cmd_ok(&repo_path, &["branch", "untrack", "main@origin"]);
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["describe", "-m", "b", "-r", "main", "--ignore-immutable"],
+    );
+    let (_, stderr) = test_env.jj_cmd_ok(&repo_path, &["branch", "track", "main@origin"]);
+    insta::assert_snapshot!(stderr, @r###"
+main (conflicted):
+  + qpvuntsm b4a6b8c5 (empty) b
+  + qpvuntsm hidden 4bfd80cd (empty) a
+  @origin (behind by 1 commits): qpvuntsm hidden 4bfd80cd (empty) a
+"###);
+}
 #[test]
 fn test_branch_track_untrack_patterns() {
     let test_env = TestEnvironment::default();