Adding initial logic + test

Author: leandrodamascena

aws_lambda_powertools/logging/logger.py

@@ -463,6 +463,10 @@ def _add_log_to_buffer(self, level, msg, filename, line, function, **kwargs):
 
         return True
 
+    def flush_buffer(self):
+        ## INITIAL IMPLEMENTATION
+        self._logger.debug("Buffer was flushed")
+
     def debug(
         self,
         msg: object,
@@ -504,7 +508,7 @@ def info(
         extra = extra or {}
         extra = {**extra, **kwargs}
 
-        # Buffer is not active, flushing
+        # Buffer is not active and we need to flush
         if not self._logger_buffer:
             return self._logger.info(
                 msg,
@@ -515,6 +519,7 @@ def info(
                 extra=extra,
             )
 
+        # Buffer log level is higher than this log level and we need to flush
         if _resolve_buffer_log_level(self._logger_buffer.minimum_log_level, "INFO"):
             return self._logger.info(
                 msg,
@@ -542,7 +547,7 @@ def warning(
         extra = extra or {}
         extra = {**extra, **kwargs}
 
-        # Buffer is not active, flushing
+        # Buffer is not active and we need to flush
         if not self._logger_buffer:
             return self._logger.warning(
                 msg,
@@ -553,6 +558,7 @@ def warning(
                 extra=extra,
             )
 
+        # Buffer log level is higher than this log level and we need to flush
         if _resolve_buffer_log_level(self._logger_buffer.minimum_log_level, "WARNING"):
             return self._logger.warning(
                 msg,
@@ -580,6 +586,12 @@ def error(
         extra = extra or {}
         extra = {**extra, **kwargs}
 
+        # Buffer is active and an error happened
+        # LoggerBufferConfig flush_on_error is True
+        # So, we need to flush the buffer
+        if self._logger_buffer and self._logger_buffer.flush_on_error:
+            self.flush_buffer()
+
         return self._logger.error(
             msg,
             *args,
@@ -602,6 +614,12 @@ def critical(
         extra = extra or {}
         extra = {**extra, **kwargs}
 
+        # Buffer is active and an error happened
+        # LoggerBufferConfig flush_on_error is True
+        # So, we need to flush the buffer
+        if self._logger_buffer and self._logger_buffer.flush_on_error:
+            self.flush_buffer()
+
         return self._logger.critical(
             msg,
             *args,
@@ -624,6 +642,12 @@ def exception(
         extra = extra or {}
         extra = {**extra, **kwargs}
 
+        # Buffer is active and an error happened
+        # LoggerBufferConfig flush_on_error is True
+        # So, we need to flush the buffer
+        if self._logger_buffer and self._logger_buffer.flush_on_error:
+            self.flush_buffer()
+
         return self._logger.exception(
             msg,
             *args,

tests/functional/logger/required_dependencies/test_powertools_logger_buffer.py

@@ -92,3 +92,51 @@ def test_logger_buffer_is_never_buffered_with_error_new(stdout, service_name):
     # THEN: We expect the log record is not buffered
     log = capture_logging_output(stdout)
     assert "Received an exception" == log["message"]
+
+
+@pytest.mark.parametrize("log_level", ["CRITICAL", "ERROR"])
+def test_logger_buffer_is_flushed_when_an_error_happens(stdout, service_name, log_level):
+    # GIVEN: A logger configured with buffer
+    logger_buffer_config = LoggerBufferConfig(max_size=10240, minimum_log_level="DEBUG", flush_on_error=True)
+    logger = Logger(level="DEBUG", service=service_name, stream=stdout, logger_buffer=logger_buffer_config)
+
+    logger.debug("this log line will be flushed")
+    logger.debug("this log line will be flushed too")
+
+    log_command = {
+        "CRITICAL": logger.critical,
+        "ERROR": logger.error,
+        "EXCEPTION": logger.exception,
+    }
+
+    # WHEN a log message is sent using the corresponding log method
+    log_message = log_command[log_level]
+    log_message("Received an exception")
+
+    # THEN: We expect the log record is not buffered
+    log = capture_multiple_logging_statements_output(stdout)
+    assert "Buffer was flushed" == log[0]["message"]
+
+
+@pytest.mark.parametrize("log_level", ["CRITICAL", "ERROR"])
+def test_logger_buffer_is_not_flushed_when_an_error_happens(stdout, service_name, log_level):
+    # GIVEN: A logger configured with buffer
+    logger_buffer_config = LoggerBufferConfig(max_size=10240, minimum_log_level="DEBUG", flush_on_error=False)
+    logger = Logger(level="DEBUG", service=service_name, stream=stdout, logger_buffer=logger_buffer_config)
+
+    logger.debug("this log line will be flushed")
+    logger.debug("this log line will be flushed too")
+
+    log_command = {
+        "CRITICAL": logger.critical,
+        "ERROR": logger.error,
+        "EXCEPTION": logger.exception,
+    }
+
+    # WHEN a log message is sent using the corresponding log method
+    log_message = log_command[log_level]
+    log_message("Received an exception")
+
+    # THEN: We expect the log record is not buffered
+    log = capture_logging_output(stdout)
+    assert "Received an exception" == log["message"]