PB-931 Fix the exc_text field handling in JSON formatter

Adding the exc_text field to the record before formatting a message.
This allows for formatting the message through the django logging
facility
Removing the addition of exc_text to the message directly. Instead adding
it to the record, so that it can be formatted through the django logging
facility

Author: schtibe

logging_utilities/formatters/json_formatter.py

@@ -343,18 +343,16 @@ def format(self, record):
         if self.add_always_extra:
             extra = self._get_extra_attrs(record)
 
-        message = self.formatMessage(record)
-
-        if self.add_always_extra:
-            self._add_extra_to_message(extra, message)
-
         if record.exc_info:
             # Cache the traceback text to avoid converting it multiple times
             # (it's constant anyway)
             if not record.exc_text:
                 record.exc_text = self.formatException(record.exc_info)
-        if record.exc_text:
-            message['exc_text'] = record.exc_text
+
+        message = self.formatMessage(record)
+
+        if self.add_always_extra:
+            self._add_extra_to_message(extra, message)
 
         if record.stack_info:
             message['stack_info'] = self.formatStack(record.stack_info)

tests/test_json_formatter.py

@@ -787,3 +787,41 @@ def test_missing_attribute(self):
                 ("message", "Composed message without extra"),
             ])
         )
+
+    def test_exc_info_without_configuration(self):
+        """
+        Test that the exc_text doesn't appear if it's not configured
+        in the logger, even though the logging call records it
+        """
+        with self.assertLogs('test_formatter', level=logging.DEBUG) as ctx:
+            logger = logging.getLogger('test_formatter')
+            self._configure_logger(
+                logger,
+                fmt=dictionary([
+                    ('level', 'levelname'),
+                    ('request', ['request.path', 'request.method']),
+                    ('message', 'message'),
+                ]),
+                remove_empty=True,
+                ignore_missing=True
+            )
+
+            try:
+                raise Exception("Error occurred")
+            except Exception as e:
+                logger.critical(
+                    str(e),
+                    exc_info=sys.exc_info(),
+                    extra={'request': {
+                        'path': '/my/path', 'method': 'GET', 'scheme': 'https'
+                    }}
+                )
+
+        self.assertDictEqual(
+            json.loads(ctx.output[0], object_pairs_hook=dictionary),
+            dictionary([
+                ("level", "CRITICAL"),
+                ("request", ["/my/path", "GET"]),
+                ("message", "Error occurred"),  # no exc_text because it wasn't configured
+            ])
+        )