fix: pass branch/tag to git clone so --single-branch fetches correct ref

src/gitingest/clone.py

@@ -96,18 +96,32 @@ async def clone_repo(config: CloneConfig, *, token: str | None = None) -> None:
         }
 
         with git_auth_context(url, token) as (git_cmd, auth_url):
+            # Determine branch/tag flag for --single-branch to fetch the correct ref
+            branch_args: list[str] = []
+            if config.branch:
+                branch_args = ["-b", config.branch]
+            elif config.tag:
+                branch_args = ["-b", config.tag]
+
             if partial_clone:
                 # For partial clones, use git.Git() with filter and sparse options
                 cmd_args = ["--single-branch", "--no-checkout", "--depth=1"]
+                cmd_args.extend(branch_args)
                 cmd_args.extend(["--filter=blob:none", "--sparse"])
                 cmd_args.extend([auth_url, local_path])
                 git_cmd.clone(*cmd_args)
             elif token and is_github_host(url):
                 # For authenticated GitHub repos, use git_cmd with auth URL
-                cmd_args = ["--single-branch", "--no-checkout", "--depth=1", auth_url, local_path]
+                cmd_args = ["--single-branch", "--no-checkout", "--depth=1"]
+                cmd_args.extend(branch_args)
+                cmd_args.extend([auth_url, local_path])
                 git_cmd.clone(*cmd_args)
             else:
                 # For non-authenticated repos, use the standard GitPython method
+                if config.branch:
+                    clone_kwargs["branch"] = config.branch
+                elif config.tag:
+                    clone_kwargs["branch"] = config.tag
                 git.Repo.clone_from(url, local_path, **clone_kwargs)
 
         logger.info("Git clone completed successfully")

tests/test_clone.py

@@ -205,6 +205,52 @@ async def test_clone_with_include_submodules(gitpython_mocks: dict) -> None:
     mock_repo.git.submodule.assert_called_with("update", "--init", "--recursive", "--depth=1")
 
 
+@pytest.mark.asyncio
+async def test_clone_with_branch_passes_branch_to_git(repo_exists_true: AsyncMock, gitpython_mocks: dict) -> None:
+    """Test that cloning with a branch passes -b to the git clone command.
+
+    Given a valid URL and a specific branch:
+    When ``clone_repo`` is called,
+    Then the clone command should include the branch so --single-branch fetches the correct ref.
+    """
+    clone_config = CloneConfig(url=DEMO_URL, local_path=LOCAL_REPO_PATH, commit=None, branch="feature-branch")
+
+    await clone_repo(clone_config)
+
+    mock_clone_from = gitpython_mocks["clone_from"]
+    mock_clone_from.assert_called_once()
+
+    _, kwargs = mock_clone_from.call_args
+    assert kwargs.get("branch") == "feature-branch", (
+        "clone_from should receive branch='feature-branch' so --single-branch fetches the correct ref"
+    )
+
+
+@pytest.mark.asyncio
+async def test_clone_with_branch_and_token_passes_branch_flag(
+    repo_exists_true: AsyncMock, gitpython_mocks: dict
+) -> None:
+    """Test that cloning with a branch and token passes -b to git.Git().clone().
+
+    Given a GitHub URL, a token, and a specific branch:
+    When ``clone_repo`` is called,
+    Then the raw git clone args should include -b <branch>.
+    """
+    clone_config = CloneConfig(
+        url=DEMO_URL, local_path=LOCAL_REPO_PATH, commit=None, branch="feature-branch"
+    )
+
+    await clone_repo(clone_config, token="ghp_testtoken123")
+
+    mock_git_cmd = gitpython_mocks["git_cmd"]
+    mock_git_cmd.clone.assert_called_once()
+
+    clone_args = mock_git_cmd.clone.call_args[0]
+    assert "-b" in clone_args, "clone args should include -b flag"
+    b_index = list(clone_args).index("-b")
+    assert clone_args[b_index + 1] == "feature-branch", "branch name should follow -b flag"
+
+
 @pytest.mark.asyncio
 async def test_check_repo_exists_with_auth_token(mocker: MockerFixture) -> None:
     """Test ``check_repo_exists`` with authentication token.