Update models.py

Author: jan-janssen

src/python_workflow_definition/models.py

@@ -1,6 +1,6 @@
 from pathlib import Path
 from typing import List, Union, Optional, Literal, Any, Annotated, Type, TypeVar
-from pydantic import BaseModel, Field, field_validator, field_serializer, model_validator
+from pydantic import BaseModel, Field, field_validator, field_serializer
 from pydantic import ValidationError
 import json
 import logging
@@ -83,13 +83,6 @@ class PythonWorkflowDefinitionEdge(BaseModel):
     source: int
     sourcePort: Optional[str] = None
 
-    @model_validator(mode='before')
-    @classmethod
-    def set_default_source_port(cls, data: Any) -> Any:
-        if isinstance(data, dict) and 'sourcePort' not in data:
-            data['sourcePort'] = None
-        return data
-
     @field_validator("sourcePort", mode="before")
     @classmethod
     def handle_default_source(cls, v: Any) -> Optional[str]:
@@ -222,6 +215,9 @@ def load_json_str(cls: Type[T], json_data: Union[str, bytes]) -> dict:
         except ValidationError:  # Catch validation errors specifically
             logger.error("Workflow model validation failed.", exc_info=True)
             raise
+        except json.JSONDecodeError:  # Catch JSON parsing errors specifically
+            logger.error("Invalid JSON format encountered.", exc_info=True)
+            raise
         except Exception as e:  # Catch any other unexpected errors
             logger.error(
                 f"An unexpected error occurred during JSON loading: {e}", exc_info=True