Apply proper annotations, fix tests, fix lint

docs/modules/ROOT/examples/merging/tutorial001.py

@@ -6,5 +6,5 @@
 def app(event: StreamTimeEvent, api: Api, cache: Cache):
     # since we passed merge_events=True all 3 incoming events
     # and their records will be merged into a single event with 9 records
-    assert len(event.records) != 9  # this will not fail
+    assert len(event.records) == 9  # this will not fail
     return event

src/corva/handlers.py

@@ -19,7 +19,6 @@
 
 import pydantic
 import redis
-from typing_extensions import assert_never
 
 from corva.api import Api
 from corva.configuration import SETTINGS
@@ -89,7 +88,13 @@ def wrapper(aws_event: Any, aws_context: Any) -> List[Any]:
                 )
                 data_transformation_type = raw_custom_event_type or raw_event_type
                 if merge_events:
-                    aws_event = _merge_events(aws_event, data_transformation_type)
+                    aws_event = _merge_events(
+                        aws_event,
+                        cast(
+                            Union[Type[RawScheduledEvent], Type[RawStreamEvent]],
+                            data_transformation_type,
+                        ),
+                    )
                 raw_events = data_transformation_type.from_raw_event(event=aws_event)
 
                 if (
@@ -567,7 +572,10 @@ def _get_custom_event_type_by_raw_aws_event(
     return None, None
 
 
-def _merge_events(aws_event: Any, data_transformation_type: Type[RawBaseEvent]) -> Any:
+def _merge_events(
+    aws_event: Any,
+    data_transformation_type: Union[Type[RawScheduledEvent], Type[RawStreamEvent]],
+) -> Any:
     """
     Merges incoming aws_events into one.
     Merge happens differently, depending on app type.
@@ -578,7 +586,10 @@ def _merge_events(aws_event: Any, data_transformation_type: Type[RawBaseEvent])
         # scheduled event
         if not isinstance(aws_event[0], dict):
             aws_event = list(itertools.chain(*aws_event))
-        is_depth = aws_event[0]["scheduler_type"] == SchedulerType.data_depth_milestone
+        scheduler_type = aws_event[0]["scheduler_type"]
+        if isinstance(scheduler_type, SchedulerType):
+            scheduler_type = scheduler_type.value
+        is_depth = scheduler_type == SchedulerType.data_depth_milestone.value
         event_start, event_end = (
             ("top_depth", "bottom_depth")
             if is_depth
@@ -595,13 +606,8 @@ def _merge_events(aws_event: Any, data_transformation_type: Type[RawBaseEvent])
         aws_event = aws_event[0]
         return aws_event
 
-    elif data_transformation_type == RawStreamEvent:
-        # stream event
-        for event in aws_event[1:]:
-            aws_event[0]["records"].extend(event["records"])
-        aws_event = [aws_event[0]]
-        return aws_event
-
-    else:
-        # unexpected event type, raise an exception
-        assert_never(data_transformation_type)  # type: ignore
+    # stream event
+    for event in aws_event[1:]:
+        aws_event[0]["records"].extend(event["records"])
+    aws_event = [aws_event[0]]
+    return aws_event

tests/unit/test_docs/test_merging.py

@@ -46,6 +46,12 @@ def test_tutorial001(context):
                             asset_id=1,
                             company_id=1,
                         ),
+                        RawTimeRecord(
+                            collection=str(),
+                            timestamp=timestamp + 2,
+                            asset_id=1,
+                            company_id=1,
+                        ),
                     ],
                     metadata=RawMetadata(
                         app_stream_id=1,
@@ -55,10 +61,10 @@ def test_tutorial001(context):
                 ).dict()
             ]
         )
-        timestamp += 2
+        timestamp += 3
 
     result_event: StreamTimeEvent = tutorial001.app(event, context)[0]
-    assert len(result_event.records) == 6, "records were not merged into a single event"
+    assert len(result_event.records) == 9, "records were not merged into a single event"
 
 
 @pytest.mark.parametrize(