eli-425 custom error for person value (#335)

* custom error for person value

* formatting

---------

Co-authored-by: karthikeyannhs <[email protected]>

Author: ayeshalshukri1-nhs

src/eligibility_signposting_api/common/error_handler.py

@@ -6,19 +6,26 @@
 from werkzeug.exceptions import HTTPException
 
 from eligibility_signposting_api.common.api_error_response import INTERNAL_SERVER_ERROR
+from eligibility_signposting_api.services.processors.token_processor import TokenError
 
 logger = logging.getLogger(__name__)
 
 
 def handle_exception(e: Exception) -> ResponseReturnValue | HTTPException:
-    logger.exception("Unexpected Exception", exc_info=e)
-
-    # Let Flask handle its own exceptions for now.
     if isinstance(e, HTTPException):
         return e
 
-    full_traceback = "".join(traceback.format_exception(e))
+    if isinstance(e, TokenError):
+        tb = traceback.extract_tb(e.__traceback__)
+        clean_traceback = "".join(traceback.format_list(tb))
+        logger.error("A ValueError occurred (value redacted). Traceback follows:\n%s", clean_traceback)
+        log_msg = f"An unexpected error occurred: {clean_traceback}"
+    else:
+        full_traceback = "".join(traceback.format_exception(e))
+        logger.exception("Unexpected Exception", exc_info=e)
+        log_msg = f"An unexpected error occurred: {full_traceback}"
+
     response = INTERNAL_SERVER_ERROR.log_and_generate_response(
-        log_message=f"An unexpected error occurred: {full_traceback}", diagnostics="An unexpected error occurred."
+        log_message=log_msg, diagnostics="An unexpected error occurred."
     )
     return make_response(response.get("body"), response.get("statusCode"), response.get("headers"))

src/eligibility_signposting_api/services/processors/token_processor.py

@@ -24,6 +24,10 @@
 }
 
 
+class TokenError(Exception):
+    """Person value error."""
+
+
 @service
 class TokenProcessor:
     @staticmethod
@@ -130,6 +134,6 @@ def apply_formatting[T](attributes: dict[str, T], attribute_name: str, date_form
         except AttributeError as error:
             message = "Invalid token format"
             raise AttributeError(message) from error
-        except Exception as error:
+        except ValueError as error:
             message = "Invalid value error"
-            raise ValueError(message) from error
+            raise TokenError(message) from error

tests/unit/processor/test_token_processor.py

@@ -1,6 +1,6 @@
 import pytest
 
-from eligibility_signposting_api.services.processors.token_processor import TokenProcessor
+from eligibility_signposting_api.services.processors.token_processor import TokenError, TokenProcessor
 
 
 @pytest.mark.parametrize(
@@ -49,5 +49,5 @@ def test_apply_formatting_raises_value_error_on_invalid_date():
     attribute_value = "DATE_OF_BIRTH"
     date_format = "%Y-%m-%d"
 
-    with pytest.raises(ValueError, match="Invalid value error$"):
+    with pytest.raises(TokenError, match="Invalid value error"):
         TokenProcessor.apply_formatting(attribute, attribute_value, date_format)