commit-check · shenxianpeng · Jul 2, 2026 · Jul 2, 2026
@@ -440,21 +440,46 @@ def validate(self, context: ValidationContext) -> ValidationResult:
         return ValidationResult.FAIL
 
     def _find_target_branch(self, pattern: str) -> str | None:
-        """Find target branch matching the pattern."""
+        """Find target branch by verifying refs directly.
+
+        Uses ``git rev-parse --verify`` for exact ref resolution instead of
+        scanning ``git branch -a`` output with a regex. Strips common regex
+        anchors (``^``, ``$``) from the pattern to obtain a branch name,
+        then attempts to verify it as a local ref first, falling back to
+        the remote tracking ref under ``origin/``.
+
+        :param pattern: The raw regex pattern from the rule config (e.g.
+            ``"^main$"`` or ``"main"``).
+        :returns: The resolved branch name if verified, ``None`` otherwise.
+        """
         import subprocess
-        import re
 
+        # Strip common regex anchors to obtain a clean branch name
+        branch_name = pattern.lstrip("^").rstrip("$").strip()
+        if not branch_name:
+            return None
+
+        # Try local branch first (refs/heads/ avoids ambiguity with tags)
         try:
-            all_branches = subprocess.check_output(
-                ["git", "branch", "-a"], encoding="utf-8"
-            ).splitlines()
+            subprocess.run(
+                ["git", "rev-parse", "--verify", f"refs/heads/{branch_name}"],
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+                check=True,
+            )
+            return branch_name
+        except subprocess.CalledProcessError:
+            pass
 
-            for branch in all_branches:
-                clean_branch = (
-                    branch.strip().replace("* ", "").replace("remotes/origin/", "")
-                )
-                if re.match(pattern, clean_branch):
-                    return clean_branch
+        # Try remote tracking branch under origin/
+        try:
+            subprocess.run(
+                ["git", "rev-parse", "--verify", f"refs/remotes/origin/{branch_name}"],
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+                check=True,
+            )
+            return branch_name
         except subprocess.CalledProcessError:
             pass
 

@@ -1,5 +1,6 @@
 """Tests for commit_check.engine module."""
 
+import subprocess
 import pytest
 import tempfile
 import os
@@ -27,7 +28,7 @@
 GIT_CONFIG_VALUE = "commit_check.engine.get_git_config_value"
 FETCH_REMOTE_REF = "commit_check.engine.fetch_remote_ref"
 GET_GIT_REMOTES = "commit_check.engine.get_git_remotes"
 REFS_HEADS_MAIN = "refs/heads/main"
 CONVENTIONAL_COMMIT_REGEX = r"^(feat|fix): .+"
 BAD_COMMIT_MSG = "Bad commit"
 USE_CONVENTIONAL_FORMAT = "Use conventional format"
@@ -842,6 +843,70 @@
             result = validator.validate(context)
             assert result == ValidationResult.PASS  # Skipped
 
+    # ------------------------------------------------------------------ #
+    #  _find_target_branch —— unit tests for the new impl
+    # ------------------------------------------------------------------ #
+
+    @patch("subprocess.run")
+    def test_find_target_branch_local_found(self, mock_run):
+        """Local branch exists: returns the stripped branch name."""
+        mock_run.return_value = subprocess.CompletedProcess(args=[], returncode=0)
+        validator = MergeBaseValidator(ValidationRule(check="merge_base"))
+        result = validator._find_target_branch("^main$")
+        assert result == "main"
+        # First call: local branch verification
+        assert mock_run.call_args_list[0][0][0][:4] == [
+            "git",
+            "rev-parse",
+            "--verify",
+            "refs/heads/main",
+        ]
+
+    @patch("subprocess.run")
+    def test_find_target_branch_local_missing_remote_found(self, mock_run):
+        """Local missing, remote tracking exists: returns the stripped branch name."""
+        mock_run.side_effect = [
+            subprocess.CalledProcessError(1, []),  # local fails
+            subprocess.CompletedProcess(args=[], returncode=0),  # remote succeeds
+        ]
+        validator = MergeBaseValidator(ValidationRule(check="merge_base"))
+        result = validator._find_target_branch("develop")
+        assert result == "develop"
+        assert mock_run.call_args_list[1][0][0][:5] == [
+            "git",
+            "rev-parse",
+            "--verify",
+            "refs/remotes/origin/develop",
+        ]
+
+    @patch("subprocess.run")
+    def test_find_target_branch_not_found(self, mock_run):
+        """Neither local nor remote exists: returns None."""
+        mock_run.side_effect = [
+            subprocess.CalledProcessError(1, []),
+            subprocess.CalledProcessError(1, []),
+        ]
+        validator = MergeBaseValidator(ValidationRule(check="merge_base"))
+        result = validator._find_target_branch("nonexistent-branch")
+        assert result is None
+
+    @patch("subprocess.run")
+    def test_find_target_branch_empty_pattern(self, mock_run):
+        """Empty or anchor-only pattern: returns None without calling subprocess."""
+        validator = MergeBaseValidator(ValidationRule(check="merge_base"))
+        result = validator._find_target_branch("")
+        assert result is None
+        mock_run.assert_not_called()
+
+    @patch("subprocess.run")
+    def test_find_target_branch_plain_name(self, mock_run):
+        """Plain branch name (no regex anchors) works correctly."""
+        mock_run.return_value = subprocess.CompletedProcess(args=[], returncode=0)
+        validator = MergeBaseValidator(ValidationRule(check="merge_base"))
+        result = validator._find_target_branch("main")
+        assert result == "main"
+        assert mock_run.call_args_list[0][0][0][3] == "refs/heads/main"
+
 
 class TestValidationEngine:
     @pytest.mark.benchmark