add test and exception handling for load_pipeline in multi_bar

Co-authored-by: maghdam <63883156+maghdam@users.noreply.github.com>

live_trading/multi_bar.py

@@ -101,9 +101,13 @@ class TradingApp:
         Loads a pre-trained classification pipeline (e.g., 'best_rf_pipeline.pkl').
         This pipeline is expected to produce SHIFTED labels [0,1,2].
         """
-        self.pipeline = joblib.load(pipeline_path)
-        logging.info(f"Loaded pipeline from {pipeline_path}")
-        log_and_print(f"Loaded pipeline from {pipeline_path}")
+        import joblib
+        try:
+            self.pipeline = joblib.load(pipeline_path)
+            log_and_print(f"Pipeline loaded from {pipeline_path}")
+        except Exception as e:
+            log_and_print(f"Failed to load pipeline: {e}", is_error=True)
+            self.pipeline = None
 
     def ml_signal_generation(self, symbol, n_bars, timeframe):
         """

tests/test_multi_bar.py

@@ -0,0 +1,48 @@
+import sys
+from unittest.mock import MagicMock
+
+# Mock dependencies before importing TradingApp
+sys.modules['MetaTrader5'] = MagicMock()
+sys.modules['pandas'] = MagicMock()
+sys.modules['numpy'] = MagicMock()
+sys.modules['ta'] = MagicMock()
+sys.modules['joblib'] = MagicMock()
+
+import unittest
+from unittest.mock import patch
+from live_trading.multi_bar import TradingApp
+
+class TestMultiBarTradingApp(unittest.TestCase):
+    @patch('live_trading.multi_bar.joblib.load')
+    @patch('live_trading.multi_bar.log_and_print')
+    def test_load_pipeline_exception_handling(self, mock_log_and_print, mock_joblib_load):
+        # Arrange
+        app = TradingApp(symbol="EURUSD", lot_size=0.01, magic_number=234003)
+        mock_joblib_load.side_effect = Exception("Mocked joblib load error")
+
+        # Act
+        app.load_pipeline("dummy_path.pkl")
+
+        # Assert
+        self.assertIsNone(app.pipeline)
+        mock_joblib_load.assert_called_once_with("dummy_path.pkl")
+        mock_log_and_print.assert_called_once_with("Failed to load pipeline: Mocked joblib load error", is_error=True)
+
+    @patch('live_trading.multi_bar.joblib.load')
+    @patch('live_trading.multi_bar.log_and_print')
+    def test_load_pipeline_success(self, mock_log_and_print, mock_joblib_load):
+        # Arrange
+        app = TradingApp(symbol="EURUSD", lot_size=0.01, magic_number=234003)
+        mock_pipeline = "mock_pipeline_instance"
+        mock_joblib_load.return_value = mock_pipeline
+
+        # Act
+        app.load_pipeline("valid_path.pkl")
+
+        # Assert
+        self.assertEqual(app.pipeline, mock_pipeline)
+        mock_joblib_load.assert_called_once_with("valid_path.pkl")
+        mock_log_and_print.assert_called_once_with("Pipeline loaded from valid_path.pkl")
+
+if __name__ == '__main__':
+    unittest.main()