SIENTIAPDE-1579: Switched from replace logic to validation + mapping

tests/utils/models/test_train_model_params.py

@@ -555,6 +555,27 @@ def test_validate_business_rules_valid_start_and_end_date(valid_train_params_dic
     params.validate_business_rules()  # Should not raise
 
 
+def test_validate_business_rules_invalid_date_format(valid_train_params_dict):
+    """Test validate_business_rules raises when date_format is not allowed."""
+    from model_manager.utils.models.train_model_params import TrainModelParams
+
+    params = TrainModelParams.from_dict(valid_train_params_dict)
+    params.date_format = 'yyyy-MM-dd'
+
+    with pytest.raises(ValueError, match='Invalid date_format'):
+        params.validate_business_rules()
+
+
+def test_validate_business_rules_valid_date_format(valid_train_params_dict):
+    """Test validate_business_rules accepts allowed date_format."""
+    from model_manager.utils.models.train_model_params import TrainModelParams
+
+    params = TrainModelParams.from_dict(valid_train_params_dict)
+    params.date_format = 'yyyy-MM-dd HH:mm:ss'
+
+    params.validate_business_rules()  # Should not raise
+
+
 def test_validate_business_rules_polynomial_regression_valid(valid_train_params_dict):
     """Test validate_business_rules accepts valid Polynomial Regression config."""
     from model_manager.utils.models.train_model_params import TrainModelParams