fix(logger): clear_state as abstract method

Author: heitorlessa

aws_lambda_powertools/logging/formatter.py

@@ -45,6 +45,7 @@ def append_keys(self, **additional_keys):
     def remove_keys(self, keys: Iterable[str]):
         raise NotImplementedError()
 
+    @abstractmethod
     def clear_state(self):
         """Removes any previously added logging keys"""
         raise NotImplementedError()

aws_lambda_powertools/logging/logger.py

@@ -386,28 +386,25 @@ def structure_logs(self, append: bool = False, **keys):
             append keys provided to logger formatter, by default False
         """
         # There are 3 operational modes for this method
-        ## 1. Append new keys to the current logger formatter; deprecated in favour of append_keys
-        ## 2. Register a Powertools Formatter for the first time
+        ## 1. Register a Powertools Formatter for the first time
+        ## 2. Append new keys to the current logger formatter; deprecated in favour of append_keys
         ## 3. Add new keys and discard existing to the registered formatter
 
-        if append:
-            # Maintenance: Add deprecation warning for major version
-            return self.append_keys(**keys)
-
+        # Mode 1
         log_keys = {**self._default_log_keys, **keys}
-
-        # Behaviour 2
         is_logger_preconfigured = getattr(self._logger, "init", False)
         if not is_logger_preconfigured:
             formatter = self.logger_formatter or LambdaPowertoolsFormatter(**log_keys)  # type: ignore
             return self.registered_handler.setFormatter(formatter)
 
-        # Behaviour 3
-        try:
-            self.registered_formatter.clear_state()
-            self.registered_formatter.append_keys(**log_keys)
-        except (AttributeError, NotImplementedError):
-            logger.warning(f"Formatter {self.registered_formatter} doesn't implement clear_state method; ignoring...")
+        # Mode 2 (legacy)
+        if append:
+            # Maintenance: Add deprecation warning for major version
+            return self.append_keys(**keys)
+
+        # Mode 3
+        self.registered_formatter.clear_state()
+        self.registered_formatter.append_keys(**log_keys)
 
     def set_correlation_id(self, value: Optional[str]):
         """Sets the correlation_id in the logging json

tests/functional/test_logger.py

@@ -525,6 +525,9 @@ def remove_keys(self, keys: Iterable[str]):
             for key in keys:
                 self.custom_format.pop(key, None)
 
+        def clear_state(self):
+            self.custom_format.clear()
+
         def format(self, record: logging.LogRecord) -> str:  # noqa: A003
             return json.dumps(
                 {