cli: list new remote branches during git fetch

CHANGELOG.md

@@ -45,6 +45,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#1252](https://github.com/martinvonz/jj/issues/1252),
   [#2971](https://github.com/martinvonz/jj/issues/2971)). This may become the
   default depending on feedback.
+* `jj git fetch` now automatically prints new remote branches and tags by default.
 
 ### Fixed bugs
 

cli/src/cli_util.rs

@@ -948,7 +948,7 @@ impl WorkspaceCommandHelper {
             return Ok(());
         }
 
-        print_git_import_stats(ui, &stats)?;
+        print_git_import_stats(ui, &stats, None)?;
         let mut tx = tx.into_inner();
         // Rebase here to show slightly different status message.
         let num_rebased = tx.mut_repo().rebase_descendants(&self.settings)?;

cli/src/commands/git.rs

@@ -447,7 +447,7 @@ fn init_git_refs(
     if !tx.mut_repo().has_changes() {
         return Ok(repo);
     }
-    print_git_import_stats(ui, &stats)?;
+    print_git_import_stats(ui, &stats, None)?;
     if colocated {
         // If git.auto-local-branch = true, local branches could be created for
         // the imported remote branches.
@@ -537,7 +537,7 @@ fn cmd_git_fetch(
             GitFetchError::InternalGitError(err) => map_git_error(err),
             _ => user_error(err),
         })?;
-        print_git_import_stats(ui, &stats.import_stats)?;
+        print_git_import_stats(ui, &stats.import_stats, Some(tx.repo().base_repo()))?;
     }
     tx.finish(
         ui,
@@ -726,7 +726,7 @@ fn do_git_clone(
         r#"Fetching into new repo in "{}""#,
         wc_path.display()
     )?;
-    let mut workspace_command = command.for_loaded_repo(ui, workspace, repo)?;
+    let mut workspace_command = command.for_loaded_repo(ui, workspace, repo.clone())?;
     maybe_add_gitignore(&workspace_command)?;
     git_repo.remote(remote_name, source).unwrap();
     let mut fetch_tx = workspace_command.start_transaction();
@@ -751,7 +751,7 @@ fn do_git_clone(
             unreachable!("we didn't provide any globs")
         }
     })?;
-    print_git_import_stats(ui, &stats.import_stats)?;
+    print_git_import_stats(ui, &stats.import_stats, None)?;
     fetch_tx.finish(ui, "fetch from git remote into empty repo")?;
     Ok((workspace_command, stats))
 }
@@ -1190,7 +1190,7 @@ fn cmd_git_import(
     // That's why cmd_git_export() doesn't export the HEAD ref.
     git::import_head(tx.mut_repo())?;
     let stats = git::import_refs(tx.mut_repo(), &command.settings().git_settings())?;
-    print_git_import_stats(ui, &stats)?;
+    print_git_import_stats(ui, &stats, None)?;
     tx.finish(ui, "import git refs")?;
     Ok(())
 }

cli/src/git_util.rs

@@ -21,8 +21,9 @@ use std::sync::Mutex;
 use std::time::Instant;
 use std::{error, iter};
 
-use jj_lib::git::{self, FailedRefExport, FailedRefExportReason, GitImportStats};
+use jj_lib::git::{self, FailedRefExport, FailedRefExportReason, GitImportStats, RefName};
 use jj_lib::git_backend::GitBackend;
+use jj_lib::op_store::{RefTarget, RemoteRef};
 use jj_lib::repo::{ReadonlyRepo, Repo as _};
 use jj_lib::store::Store;
 use jj_lib::workspace::Workspace;
@@ -172,17 +173,122 @@ pub fn with_remote_git_callbacks<T>(
     f(callbacks)
 }
 
-pub fn print_git_import_stats(ui: &mut Ui, stats: &GitImportStats) -> Result<(), CommandError> {
+pub fn print_git_import_stats(
+    ui: &mut Ui,
+    stats: &GitImportStats,
+    query_ref_stats: Option<&ReadonlyRepo>,
+) -> Result<(), CommandError> {
+    if let (Some(repo), true) = (query_ref_stats, !stats.changed_remote_refs.is_empty()) {
+        let mut remote_branches = Vec::new();
+        let mut tags = Vec::new();
+        let mut local_branches = Vec::new();
+
+        // group the references by type
+        for (refname, (remote_ref, ref_target)) in &stats.changed_remote_refs {
+            let ref_status = RefStatus::new(refname, remote_ref, ref_target, repo);
+            match refname {
+                RefName::RemoteBranch { .. } => remote_branches.push(ref_status),
+                RefName::Tag(_) => tags.push(ref_status),
+                RefName::LocalBranch(_) => local_branches.push(ref_status),
+            }
+        }
+
+        let grouped_refs = vec![remote_branches, tags, local_branches];
+
+        for refs in grouped_refs {
+            if let Some(max_ref_name_len) = refs.iter().map(|status| status.ref_name.len()).max() {
+                for status in refs {
+                    status.output(max_ref_name_len, &mut ui.stderr())?;
+                }
+                writeln!(ui.stderr())?;
+            }
+        }
+    }
+
     if !stats.abandoned_commits.is_empty() {
         writeln!(
             ui.stderr(),
             "Abandoned {} commits that are no longer reachable.",
             stats.abandoned_commits.len()
         )?;
     }
+
     Ok(())
 }
 
+struct RefStatus {
+    ref_name: String,
+    tracking_status: TrackingStatus,
+    import_status: ImportStatus,
+}
+
+impl RefStatus {
+    fn new(
+        ref_name: &RefName,
+        remote_ref: &RemoteRef,
+        ref_target: &RefTarget,
+        repo: &ReadonlyRepo,
+    ) -> Self {
+        let mut tracking_status = TrackingStatus::Untracked;
+        let ref_name = match ref_name {
+            RefName::RemoteBranch { branch, remote } => {
+                if repo.view().get_remote_branch(branch, remote).is_tracking() {
+                    tracking_status = TrackingStatus::Tracked;
+                }
+                format!("branch: {branch}@{remote}")
+            }
+            RefName::Tag(tag) => format!("tag: {tag}"),
+            RefName::LocalBranch(branch) => format!("branch: {branch}"),
+        };
+
+        let import_status = match (remote_ref.target.is_absent(), ref_target.is_present()) {
+            (true, true) => ImportStatus::New,
+            (false, false) => ImportStatus::Deleted,
+            _ => ImportStatus::Updated,
+        };
+
+        Self {
+            ref_name,
+            tracking_status,
+            import_status,
+        }
+    }
+
+    fn output(&self, max_ref_name_len: usize, out: &mut dyn Write) -> std::io::Result<()> {
+        const MAX_REF_NAME_LEN: usize = 40;
+        let tracking_status = match self.tracking_status {
+            TrackingStatus::Tracked => "tracked",
+            TrackingStatus::Untracked => "untracked",
+        };
+
+        let import_status = match self.import_status {
+            ImportStatus::New => "new",
+            ImportStatus::Deleted => "deleted",
+            ImportStatus::Updated => "updated",
+        };
+
+        // This ensures alignment of the statuses that follow
+        let padded_ref_name = format!(
+            "{:width$}",
+            self.ref_name,
+            width = std::cmp::min(max_ref_name_len, MAX_REF_NAME_LEN)
+        );
+
+        writeln!(out, "{padded_ref_name} [{import_status}] {tracking_status}")
+    }
+}
+
+enum TrackingStatus {
+    Tracked,
+    Untracked,
+}
+
+enum ImportStatus {
+    New,
+    Deleted,
+    Updated,
+}
+
 pub fn print_failed_git_export(
     ui: &Ui,
     failed_branches: &[FailedRefExport],

cli/tests/test_branch_command.rs

@@ -536,7 +536,10 @@ fn test_branch_forget_fetched_branch() {
     // We can fetch feature1 again.
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch", "--remote=origin"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [new] untracked
+
+    "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
     feature1: mzyxwzks 9f01a0e0 message
       @origin: mzyxwzks 9f01a0e0 message
@@ -548,7 +551,10 @@ fn test_branch_forget_fetched_branch() {
     // Fetch works even without the export-import
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch", "--remote=origin"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [new] untracked
+
+    "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
     feature1: mzyxwzks 9f01a0e0 message
       @origin: mzyxwzks 9f01a0e0 message
@@ -574,7 +580,10 @@ fn test_branch_forget_fetched_branch() {
     // Fetching a moved branch does not create a conflict
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch", "--remote=origin"]);
     insta::assert_snapshot!(stdout, @"");
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [new] untracked
+
+    "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
     feature1: ooosovrs 38aefb17 (empty) another message
       @origin: ooosovrs 38aefb17 (empty) another message
@@ -687,7 +696,12 @@ fn test_branch_track_untrack() {
     );
     test_env.add_config("git.auto-local-branch = false");
     let (_stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch"]);
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [new] untracked
+    branch: feature2@origin [new] untracked
+    branch: main@origin     [new] untracked
+
+    "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
     feature1@origin: sptzoqmo 7b33f629 commit 1
     feature2@origin: sptzoqmo 7b33f629 commit 1
@@ -759,7 +773,12 @@ fn test_branch_track_untrack() {
         ],
     );
     let (_stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch"]);
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [updated] untracked
+    branch: feature2@origin [updated] untracked
+    branch: main@origin     [updated] tracked
+
+    "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
     feature1: sptzoqmo 7b33f629 commit 1
     feature1@origin: mmqqkyyt 40dabdaf commit 2
@@ -791,6 +810,11 @@ fn test_branch_track_untrack() {
     test_env.add_config("git.auto-local-branch = true");
     let (_stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch"]);
     insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [updated] untracked
+    branch: feature2@origin [updated] untracked
+    branch: feature3@origin [new] untracked
+    branch: main@origin     [updated] tracked
+
     Abandoned 1 commits that are no longer reachable.
     "###);
     insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
@@ -847,7 +871,11 @@ fn test_branch_track_untrack_patterns() {
     // Fetch new commit without auto tracking
     test_env.add_config("git.auto-local-branch = false");
     let (_stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["git", "fetch"]);
-    insta::assert_snapshot!(stderr, @"");
+    insta::assert_snapshot!(stderr, @r###"
+    branch: feature1@origin [new] untracked
+    branch: feature2@origin [new] untracked
+
+    "###);
 
     // Track local branch
     test_env.jj_cmd_ok(&repo_path, &["branch", "create", "main"]);

cli/tests/test_git_colocated.rs

@@ -507,6 +507,9 @@ fn test_git_colocated_fetch_deleted_or_moved_branch() {
     let (stdout, stderr) = test_env.jj_cmd_ok(&clone_path, &["git", "fetch"]);
     insta::assert_snapshot!(stdout, @"");
     insta::assert_snapshot!(stderr, @r###"
+    branch: B_to_delete@origin [deleted] tracked
+    branch: C_to_move@origin   [updated] tracked
+
     Abandoned 2 commits that are no longer reachable.
     "###);
     // "original C" and "B_to_delete" are abandoned, as the corresponding branches