add excpetion_handlers module

app/exception_handlers/validation.py

@@ -0,0 +1,39 @@
+from fastapi import Request
+from fastapi.exceptions import ResponseValidationError
+from fastapi.responses import JSONResponse
+
+from app.exception_handlers.base import BaseExceptionHandler
+
+
+class ResponseValidationExceptionHandler(BaseExceptionHandler):
+    """Handles response validation exceptions."""
+
+    @classmethod
+    async def handle_exception(cls, request: Request, exc: ResponseValidationError) -> JSONResponse:
+        request_info = await cls.extract_request_info(request)
+        errors = exc.errors()
+
+        # Check if this is a None/null response case
+        is_none_response = False
+        for error in errors:
+            if error.get("input") is None and "valid dictionary" in error.get("msg", ""):
+                is_none_response = True
+                break
+
+        await cls.log_error(
+            "Response validation error occurred",
+            request_info,
+            validation_errors=errors,
+            is_none_response=is_none_response
+        )
+
+        if is_none_response:
+            return JSONResponse(
+                status_code=404,
+                content={"no_response": "The requested resource was not found"}
+            )
+        else:
+            return JSONResponse(
+                status_code=422,
+                content={"response_format_error": errors}
+            )