[EventHubs] no-op instead of raising error when sending out empty event data batch (#16638)

* better error message

* remove extra blank line

* should be a no-op instead of raising error

* update changelog

* fix pylint

* fix pytest

* fix async test

* Update sdk/eventhub/azure-eventhub/CHANGELOG.md

Co-authored-by: swathipil <76007337+swathipil@users.noreply.github.com>

Co-authored-by: swathipil <76007337+swathipil@users.noreply.github.com>

Author: yunhaoling

sdk/eventhub/azure-eventhub/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## 5.3.1 (Unreleased)
 
+**Bug fixes**
+
+- Sending empty `event_data_batch` will be a no-op now instead of raising error.
 
 ## 5.3.0 (2021-02-08)
 

sdk/eventhub/azure-eventhub/azure/eventhub/_producer_client.py

@@ -255,6 +255,10 @@ def send_batch(self, event_data_batch, **kwargs):
         partition_id = (
             to_send_batch._partition_id or ALL_PARTITIONS  # pylint:disable=protected-access
         )
+
+        if len(to_send_batch) == 0:
+            return
+
         send_timeout = kwargs.pop("timeout", None)
         try:
             cast(EventHubProducer, self._producers[partition_id]).send(

sdk/eventhub/azure-eventhub/azure/eventhub/aio/_producer_client_async.py

@@ -284,6 +284,9 @@ async def send_batch(
             to_send_batch = await self.create_batch(partition_id=partition_id, partition_key=partition_key)
             to_send_batch._load_events(event_data_batch)  # pylint:disable=protected-access
 
+        if len(to_send_batch) == 0:
+            return
+
         partition_id = (
             to_send_batch._partition_id or ALL_PARTITIONS  # pylint:disable=protected-access
         )

sdk/eventhub/azure-eventhub/tests/livetest/asynctests/test_send_async.py

@@ -30,6 +30,8 @@ async def test_send_with_partition_key_async(connstr_receivers):
                 data_val += 1
                 await client.send_batch(batch)
 
+        await client.send_batch(await client.create_batch())
+
     found_partition_keys = {}
     for index, partition in enumerate(receivers):
         received = partition.receive_message_batch(timeout=5000)
@@ -202,8 +204,7 @@ async def test_send_list_partition_async(connstr_receivers):
 
 
 @pytest.mark.parametrize("to_send, exception_type",
-                         [([], EventDataSendError),
-                          ([EventData("A"*1024)]*1100, ValueError),
+                         [([EventData("A"*1024)]*1100, ValueError),
                           ("any str", AttributeError)
                           ])
 @pytest.mark.liveTest

sdk/eventhub/azure-eventhub/tests/livetest/synctests/test_send.py

@@ -28,6 +28,8 @@ def test_send_with_partition_key(connstr_receivers):
                 data_val += 1
                 client.send_batch(batch)
 
+        client.send_batch(client.create_batch())
+
     found_partition_keys = {}
     for index, partition in enumerate(receivers):
         received = partition.receive_message_batch(timeout=5000)
@@ -209,8 +211,7 @@ def test_send_list_partition(connstr_receivers):
 
 
 @pytest.mark.parametrize("to_send, exception_type",
-                         [([], EventDataSendError),
-                          ([EventData("A"*1024)]*1100, ValueError),
+                         [([EventData("A"*1024)]*1100, ValueError),
                           ("any str", AttributeError)
                           ])
 @pytest.mark.liveTest