git: test import of remote-only branch

This test coverage will become more important when we make changes to
remote branch importing.

lib/tests/test_git.rs

@@ -71,6 +71,7 @@ fn test_import_refs() {
     let commit3 = empty_git_commit(&git_repo, "refs/heads/feature1", &[&commit2]);
     let commit4 = empty_git_commit(&git_repo, "refs/heads/feature2", &[&commit2]);
     let commit5 = empty_git_commit(&git_repo, "refs/tags/v1.0", &[&commit1]);
+    let commit6 = empty_git_commit(&git_repo, "refs/remotes/origin/feature3", &[&commit1]);
     // Should not be imported
     empty_git_commit(&git_repo, "refs/notes/x", &[&commit2]);
     empty_git_commit(&git_repo, "refs/remotes/origin/HEAD", &[&commit2]);
@@ -87,7 +88,8 @@ fn test_import_refs() {
     let expected_heads = hashset! {
         jj_id(&commit3),
         jj_id(&commit4),
-        jj_id(&commit5)
+        jj_id(&commit5),
+        jj_id(&commit6)
     };
     assert_eq!(*view.heads(), expected_heads);
 
@@ -117,13 +119,23 @@ fn test_import_refs() {
         view.branches().get("feature2"),
         Some(expected_feature2_branch).as_ref()
     );
+    let expected_feature3_branch = BranchTarget {
+        local_target: Some(RefTarget::Normal(jj_id(&commit6))),
+        remote_targets: btreemap! {
+          "origin".to_string() => RefTarget::Normal(jj_id(&commit6)),
+        },
+    };
+    assert_eq!(
+        view.branches().get("feature3"),
+        Some(expected_feature3_branch).as_ref()
+    );
 
     assert_eq!(
         view.tags().get("v1.0"),
         Some(RefTarget::Normal(jj_id(&commit5))).as_ref()
     );
 
-    assert_eq!(view.git_refs().len(), 5);
+    assert_eq!(view.git_refs().len(), 6);
     assert_eq!(
         view.git_refs().get("refs/heads/main"),
         Some(RefTarget::Normal(jj_id(&commit2))).as_ref()
@@ -140,6 +152,10 @@ fn test_import_refs() {
         view.git_refs().get("refs/remotes/origin/main"),
         Some(RefTarget::Normal(jj_id(&commit1))).as_ref()
     );
+    assert_eq!(
+        view.git_refs().get("refs/remotes/origin/feature3"),
+        Some(RefTarget::Normal(jj_id(&commit6))).as_ref()
+    );
     assert_eq!(
         view.git_refs().get("refs/tags/v1.0"),
         Some(RefTarget::Normal(jj_id(&commit5))).as_ref()

tests/test_git_import_export.rs

@@ -11,6 +11,7 @@
 // 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::{get_stderr_string, TestEnvironment};
 
@@ -37,3 +38,46 @@ fn test_git_export_conflicting_git_refs() {
     export or their "parent" branches.
     "###);
 }
+
+#[test]
+fn test_git_import_remote_only_branch() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    // Create non-empty git repo to add as a remote
+    let git_repo_path = test_env.env_root().join("git-repo");
+    let git_repo = git2::Repository::init(git_repo_path).unwrap();
+    let signature =
+        git2::Signature::new("Some One", "some.one@example.com", &git2::Time::new(0, 0)).unwrap();
+    let mut tree_builder = git_repo.treebuilder(None).unwrap();
+    let file_oid = git_repo.blob(b"content").unwrap();
+    tree_builder
+        .insert("file", file_oid, git2::FileMode::Blob.into())
+        .unwrap();
+    let tree_oid = tree_builder.write().unwrap();
+    let tree = git_repo.find_tree(tree_oid).unwrap();
+    test_env.jj_cmd_success(
+        &repo_path,
+        &["git", "remote", "add", "origin", "../git-repo"],
+    );
+
+    git_repo
+        .commit(
+            Some("refs/heads/feature1"),
+            &signature,
+            &signature,
+            "message",
+            &tree,
+            &[],
+        )
+        .unwrap();
+    test_env.jj_cmd_success(&repo_path, &["git", "fetch", "--remote=origin"]);
+    insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
+    feature1: 9f01a0e04879 message
+    "###);
+}
+
+fn get_branch_output(test_env: &TestEnvironment, repo_path: &Path) -> String {
+    test_env.jj_cmd_success(repo_path, &["branch", "list"])
+}