Log handled errors to warning (#1926)

Fixes #1925.

Changes proposed in this pull request:

 - Log handled errors to `warning` instead of `error`.
- Log validation errors to `info` because the intent of the log lines in
informational. The error is handled by raising a new error.

---------

Co-authored-by: Alex Fechner <alex.fechner@stryker.com>

connexion/middleware/exceptions.py

@@ -72,7 +72,12 @@ def add_exception_handler(
     @staticmethod
     def problem_handler(_request: ConnexionRequest, exc: ProblemException):
         """Default handler for Connexion ProblemExceptions"""
-        logger.error("%r", exc)
+
+        if 400 <= exc.status <= 499:
+            logger.warning("%r", exc)
+        else:
+            logger.error("%r", exc)
+
         return exc.to_problem()
 
     @staticmethod
@@ -81,6 +86,12 @@ def http_exception(
         _request: StarletteRequest, exc: HTTPException, **kwargs
     ) -> StarletteResponse:
         """Default handler for Starlette HTTPException"""
+
+        if 400 <= exc.status_code <= 499:
+            logger.warning("%r", exc)
+        else:
+            logger.error("%r", exc)
+
         logger.error("%r", exc)
         return problem(
             title=http_facts.HTTP_STATUS_CODES.get(exc.status_code),

connexion/validators/json.py

@@ -68,7 +68,7 @@ def _validate(self, body: t.Any) -> t.Optional[dict]:
             return self._validator.validate(body)
         except ValidationError as exception:
             error_path_msg = format_error_with_path(exception=exception)
-            logger.error(
+            logger.info(
                 f"Validation error: {exception.message}{error_path_msg}",
                 extra={"validator": "body"},
             )
@@ -77,7 +77,8 @@ def _validate(self, body: t.Any) -> t.Optional[dict]:
 
 class DefaultsJSONRequestBodyValidator(JSONRequestBodyValidator):
     """Request body validator for json content types which fills in default values. This Validator
-    intercepts the body, makes changes to it, and replays it for the next ASGI application."""
+    intercepts the body, makes changes to it, and replays it for the next ASGI application.
+    """
 
     MUTABLE_VALIDATION = True
     """This validator might mutate to the body."""
@@ -129,7 +130,7 @@ def _validate(self, body: dict):
             self.validator.validate(body)
         except ValidationError as exception:
             error_path_msg = format_error_with_path(exception=exception)
-            logger.error(
+            logger.warning(
                 f"Validation error: {exception.message}{error_path_msg}",
                 extra={"validator": "body"},
             )