Merge pull request #14687 from nathanielmanistaatgoogle/early-ok

Verify early OK behavior.

6 files changed, 374 insertions, 24 deletions

diff --git a/src/python/grpcio_tests/tests/tests.json b/src/python/grpcio_tests/tests/tests.json
index e033c1063f..0f6fd983aa 100644
--- a/src/python/grpcio_tests/tests/tests.json
+++ b/src/python/grpcio_tests/tests/tests.json
@@ -38,6 +38,168 @@
   "unit._cython.cygrpc_test.InsecureServerInsecureClient",
   "unit._cython.cygrpc_test.SecureServerSecureClient",
   "unit._cython.cygrpc_test.TypeSmokeTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyEmptyRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManyLargeRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ManySmallRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoEmptyRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoLargeRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.TwoSmallRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroEmptyRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroLargeRequestsZeroReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsTwoReadZeroSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadManyEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadManyLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadManySmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadTwoEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadTwoLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadTwoSmallResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadZeroEmptyResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadZeroLargeResponsesEarlyOKTest",
+  "unit._early_ok_test.ZeroSmallRequestsZeroReadZeroSmallResponsesEarlyOKTest",
   "unit._empty_message_test.EmptyMessageTest",
   "unit._exit_test.ExitTest",
   "unit._interceptor_test.InterceptorTest",
diff --git a/src/python/grpcio_tests/tests/unit/_compression_test.py b/src/python/grpcio_tests/tests/unit/_compression_test.py
index 7550cd39ba..da1996b1d1 100644
--- a/src/python/grpcio_tests/tests/unit/_compression_test.py
+++ b/src/python/grpcio_tests/tests/unit/_compression_test.py
@@ -32,12 +32,10 @@ def handle_unary(request, servicer_context):
 
 
 def handle_stream(request_iterator, servicer_context):
-    # TODO(issue:#6891) We should be able to remove this loop,
-    # and replace with return; yield
     servicer_context.send_initial_metadata([('grpc-internal-encoding-request',
                                              'gzip')])
-    for request in request_iterator:
-        yield request
+    return
+    yield
 
 
 class _MethodHandler(grpc.RpcMethodHandler):
diff --git a/src/python/grpcio_tests/tests/unit/_early_ok_test.py b/src/python/grpcio_tests/tests/unit/_early_ok_test.py
new file mode 100644
index 0000000000..041532c661
--- /dev/null
+++ b/src/python/grpcio_tests/tests/unit/_early_ok_test.py
@@ -0,0 +1,206 @@
+# Copyright 2018 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Tests servicers sending OK status without having read all requests.
+
+This is a regression test of https://github.com/grpc/grpc/issues/6891.
+"""
+
+import enum
+import unittest
+
+import six
+
+import grpc
+
+from tests.unit import test_common
+from tests.unit.framework.common import test_constants
+
+_RPC_METHOD = '/serffice/Meffod'
+
+
+@enum.unique
+class _MessageCount(enum.Enum):
+
+    ZERO = (
+        0,
+        'Zero',
+    )
+    TWO = (
+        1,
+        'Two',
+    )
+    MANY = (
+        test_constants.STREAM_LENGTH,
+        'Many',
+    )
+
+
+@enum.unique
+class _MessageSize(enum.Enum):
+    EMPTY = (
+        0,
+        'Empty',
+    )
+    SMALL = (
+        32,
+        'Small',
+    )  # Smaller than any flow control window.
+    LARGE = (
+        3 * 1024 * 1024,
+        'Large',
+    )  # Larger than any flow control window.
+
+
+_ZERO_MESSAGE = b''
+_SMALL_MESSAGE = b'\x07' * _MessageSize.SMALL.value[0]
+_LARGE_MESSAGE = b'abc' * (_MessageSize.LARGE.value[0] // 3)
+
+
+@enum.unique
+class _ReadRequests(enum.Enum):
+
+    ZERO = (
+        0,
+        'Zero',
+    )
+    TWO = (
+        2,
+        'Two',
+    )
+
+
+class _Case(object):
+
+    def __init__(self, request_count, request_size, request_reading,
+                 response_count, response_size):
+        self.request_count = request_count
+        self.request_size = request_size
+        self.request_reading = request_reading
+        self.response_count = response_count
+        self.response_size = response_size
+
+    def create_test_case_name(self):
+        return '{}{}Requests{}Read{}{}ResponsesEarlyOKTest'.format(
+            self.request_count.value[1], self.request_size.value[1],
+            self.request_reading.value[1], self.response_count.value[1],
+            self.response_size.value[1])
+
+
+def _message(message_size):
+    if message_size is _MessageSize.EMPTY:
+        return _ZERO_MESSAGE
+    elif message_size is _MessageSize.SMALL:
+        return _SMALL_MESSAGE
+    elif message_size is _MessageSize.LARGE:
+        return _LARGE_MESSAGE
+
+
+def _messages_to_send(count, size):
+    for _ in range(count.value[0]):
+        yield _message(size)
+
+
+def _draw_requests(case, request_iterator):
+    for _ in range(
+            min(case.request_count.value[0], case.request_reading.value[0])):
+        next(request_iterator)
+
+
+def _draw_responses(case, response_iterator):
+    for _ in range(case.response_count.value[0]):
+        next(response_iterator)
+
+
+class _MethodHandler(grpc.RpcMethodHandler):
+
+    def __init__(self, case):
+        self.request_streaming = True
+        self.response_streaming = True
+        self.request_deserializer = None
+        self.response_serializer = None
+        self.unary_unary = None
+        self.unary_stream = None
+        self.stream_unary = None
+        self._case = case
+
+    def stream_stream(self, request_iterator, servicer_context):
+        _draw_requests(self._case, request_iterator)
+
+        for response in _messages_to_send(self._case.response_count,
+                                          self._case.response_size):
+            yield response
+
+
+class _GenericHandler(grpc.GenericRpcHandler):
+
+    def __init__(self, case):
+        self._case = case
+
+    def service(self, handler_call_details):
+        return _MethodHandler(self._case)
+
+
+class _EarlyOkTest(unittest.TestCase):
+
+    def setUp(self):
+        self._server = test_common.test_server()
+        port = self._server.add_insecure_port('[::]:0')
+        self._server.add_generic_rpc_handlers((_GenericHandler(self.case),))
+        self._server.start()
+
+        self._channel = grpc.insecure_channel('localhost:%d' % port)
+        self._multi_callable = self._channel.stream_stream(_RPC_METHOD)
+
+    def tearDown(self):
+        self._server.stop(None)
+
+    def test_early_ok(self):
+        requests = _messages_to_send(self.case.request_count,
+                                     self.case.request_size)
+
+        response_iterator_call = self._multi_callable(requests)
+
+        _draw_responses(self.case, response_iterator_call)
+
+        self.assertIs(grpc.StatusCode.OK, response_iterator_call.code())
+
+
+def _cases():
+    for request_count in _MessageCount:
+        for request_size in _MessageSize:
+            for request_reading in _ReadRequests:
+                for response_count in _MessageCount:
+                    for response_size in _MessageSize:
+                        yield _Case(request_count, request_size,
+                                    request_reading, response_count,
+                                    response_size)
+
+
+def _test_case_classes():
+    for case in _cases():
+        yield type(case.create_test_case_name(), (_EarlyOkTest,), {
+            'case': case,
+            '__module__': _EarlyOkTest.__module__,
+        })
+
+
+def load_tests(loader, tests, pattern):
+    return unittest.TestSuite(
+        tests=tuple(
+            loader.loadTestsFromTestCase(test_case_class)
+            for test_case_class in _test_case_classes()))
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)
diff --git a/src/python/grpcio_tests/tests/unit/_metadata_code_details_test.py b/src/python/grpcio_tests/tests/unit/_metadata_code_details_test.py
index ca10bd4dab..a6cdf32e5b 100644
--- a/src/python/grpcio_tests/tests/unit/_metadata_code_details_test.py
+++ b/src/python/grpcio_tests/tests/unit/_metadata_code_details_test.py
@@ -107,9 +107,6 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            # TODO(https://github.com/grpc/grpc/issues/6891): just ignore the
-            # request iterator.
-            list(request_iterator)
             if self._abort_call:
                 context.abort(self._code, self._details)
             else:
@@ -127,9 +124,6 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            # TODO(https://github.com/grpc/grpc/issues/6891): just ignore the
-            # request iterator.
-            list(request_iterator)
             if self._abort_call:
                 context.abort(self._code, self._details)
             else:
diff --git a/src/python/grpcio_tests/tests/unit/_metadata_test.py b/src/python/grpcio_tests/tests/unit/_metadata_test.py
index 5908421011..2309eeb733 100644
--- a/src/python/grpcio_tests/tests/unit/_metadata_test.py
+++ b/src/python/grpcio_tests/tests/unit/_metadata_test.py
@@ -117,9 +117,6 @@ def handle_stream_unary(test, request_iterator, servicer_context):
     validate_client_metadata(test, servicer_context)
     servicer_context.send_initial_metadata(_INITIAL_METADATA)
     servicer_context.set_trailing_metadata(_TRAILING_METADATA)
-    # TODO(issue:#6891) We should be able to remove this loop
-    for request in request_iterator:
-        pass
     return _RESPONSE
 
 
@@ -127,10 +124,8 @@ def handle_stream_stream(test, request_iterator, servicer_context):
     validate_client_metadata(test, servicer_context)
     servicer_context.send_initial_metadata(_INITIAL_METADATA)
     servicer_context.set_trailing_metadata(_TRAILING_METADATA)
-    # TODO(issue:#6891) We should be able to remove this loop,
-    # and replace with return; yield
-    for request in request_iterator:
-        yield _RESPONSE
+    return
+    yield
 
 
 class _MethodHandler(grpc.RpcMethodHandler):
diff --git a/src/python/grpcio_tests/tests/unit/_resource_exhausted_test.py b/src/python/grpcio_tests/tests/unit/_resource_exhausted_test.py
index df4b129018..e35f8f10d4 100644
--- a/src/python/grpcio_tests/tests/unit/_resource_exhausted_test.py
+++ b/src/python/grpcio_tests/tests/unit/_resource_exhausted_test.py
@@ -77,18 +77,13 @@ def handle_unary_stream(trigger, request, servicer_context):
 
 def handle_stream_unary(trigger, request_iterator, servicer_context):
     trigger.await_trigger()
-    # TODO(issue:#6891) We should be able to remove this loop
-    for request in request_iterator:
-        pass
     return _RESPONSE
 
 
 def handle_stream_stream(trigger, request_iterator, servicer_context):
     trigger.await_trigger()
-    # TODO(issue:#6891) We should be able to remove this loop,
-    # and replace with return; yield
-    for request in request_iterator:
-        yield _RESPONSE
+    return
+    yield
 
 
 class _MethodHandler(grpc.RpcMethodHandler):