refactor review-plan safety and validation

tests/test_scanner.py

@@ -137,6 +137,54 @@ class TestScanLibrary:
         assert len(result) == 1
         assert result[0].path == visible_file
 
+    def test_scan_keeps_partial_find_results_when_find_exits_nonzero(self, tmp_path):
+        """Non-zero find exits should keep partial stdout and log the contract."""
+        movie_dir = tmp_path / "movie"
+        movie_dir.mkdir()
+        visible_file = movie_dir / "visible.mp4"
+        visible_file.touch()
+
+        fake_stdout = f"{visible_file}\0".encode()
+
+        with patch('subprocess.Popen') as mock_popen, patch("vlm.scanner.logger.warning") as mock_warning:
+            process = MagicMock()
+            process.communicate.return_value = (fake_stdout, b"Permission denied")
+            process.returncode = 1
+            mock_popen.return_value = process
+
+            config = Config(library_root=tmp_path)
+            result = scan_library(tmp_path, config, include_video_metadata=False)
+
+        warning_messages = [
+            call.args[0] % call.args[1:] if len(call.args) > 1 else call.args[0]
+            for call in mock_warning.call_args_list
+        ]
+        assert len(result) == 1
+        assert result[0].path == visible_file
+        assert any("using 1 partial scan result" in message for message in warning_messages)
+        assert any("Permission denied" in message for message in warning_messages)
+
+    def test_scan_returns_empty_when_find_exits_nonzero_without_stdout(self, tmp_path):
+        """Non-zero find exits without stdout should produce an empty result deterministically."""
+        (tmp_path / "movie").mkdir()
+
+        with patch('subprocess.Popen') as mock_popen, patch("vlm.scanner.logger.warning") as mock_warning:
+            process = MagicMock()
+            process.communicate.return_value = (b"", b"Permission denied")
+            process.returncode = 1
+            mock_popen.return_value = process
+
+            config = Config(library_root=tmp_path)
+            result = scan_library(tmp_path, config, include_video_metadata=False)
+
+        warning_messages = [
+            call.args[0] % call.args[1:] if len(call.args) > 1 else call.args[0]
+            for call in mock_warning.call_args_list
+        ]
+        assert result == []
+        assert any("produced no scan results" in message for message in warning_messages)
+        assert any("Permission denied" in message for message in warning_messages)
+
     def test_scan_falls_back_when_find_is_unavailable(self, tmp_path):
         """Test scan_library falls back to recursive scanning if find is unavailable."""
         movie_dir = tmp_path / "movie"