Events: put_events() now throws a warning when Detail field is not a dict (#6875)

moto/events/models.py

@@ -1327,7 +1327,11 @@ class EventsBackend(BaseBackend):
                 )
             else:
                 try:
-                    json.loads(event["Detail"])
+                    detail = json.loads(event["Detail"])
+                    if not isinstance(detail, dict):
+                        warnings.warn(
+                            f"EventDetail should be of type dict - types such as {type(detail)} are ignored by AWS"
+                        )
                 except ValueError:  # json.JSONDecodeError exists since Python 3.5
                     entries.append(
                         {

tests/test_events/test_events.py

@@ -1,13 +1,14 @@
 import json
 import random
 import unittest
+import warnings
 from datetime import datetime, timezone
 
 import boto3
 import pytest
 from botocore.exceptions import ClientError
 
-from moto import mock_logs
+from moto import mock_logs, settings
 from moto.core import DEFAULT_ACCOUNT_ID as ACCOUNT_ID
 from moto.core.utils import iso_8601_datetime_without_milliseconds
 from moto.events import mock_events
@@ -682,6 +683,12 @@ def test_put_events():
     assert response["FailedEntryCount"] == 0
     assert len(response["Entries"]) == 1
 
+    if settings.TEST_DECORATOR_MODE:
+        event["Detail"] = json.dumps([{"Key": "k", "Value": "v"}])
+        with warnings.catch_warnings(record=True) as w:
+            client.put_events(Entries=[event])
+        assert "EventDetail should be of type dict" in str(w[0].message)
+
 
 @mock_events
 def test_put_events_error_too_many_entries():