fix: api_gateway debug events now end with newlines

Newlines are now emitted at the end of api_gateway debug JSON events.
This resolves an issue where the debug events would be combined with
CloudWatch EMF metrics, resulting in the metrics being ignored.

Author: wostenbf

aws_lambda_powertools/event_handler/api_gateway.py

@@ -531,7 +531,7 @@ def resolve(self, event, context) -> Dict[str, Any]:
             event = event.raw_event
 
         if self._debug:
-            print(self._json_dump(event), end="")
+            print(self._json_dump(event))
 
         # Populate router(s) dependencies without keeping a reference to each registered router
         BaseRouter.current_event = self._to_proxy_event(event)

tests/functional/event_handler/test_api_gateway.py

@@ -829,6 +829,7 @@ def test_debug_print_event(capsys):
 
     # THEN print the event
     out, err = capsys.readouterr()
+    assert "\n" in out
     assert json.loads(out) == event