Stop using mutable types for default arg values

Using mutable types for default args is typically a no-no unless their
surprising behavior is being explicitly abused, for an explanation see:
http://effbot.org/zone/default-values.htm

Fix dpkp#1212

Author: jeffwidman

kafka/client.py

@@ -637,23 +637,23 @@ def load_metadata_for_topics(self, *topics, **kwargs):
                     )
 
     @time_metric('metadata')
-    def send_metadata_request(self, payloads=[], fail_on_error=True,
+    def send_metadata_request(self, payloads=(), fail_on_error=True,
                               callback=None):
         encoder = KafkaProtocol.encode_metadata_request
         decoder = KafkaProtocol.decode_metadata_response
 
         return self._send_broker_unaware_request(payloads, encoder, decoder)
 
     @time_metric('consumer_metadata')
-    def send_consumer_metadata_request(self, payloads=[], fail_on_error=True,
+    def send_consumer_metadata_request(self, payloads=(), fail_on_error=True,
                                        callback=None):
         encoder = KafkaProtocol.encode_consumer_metadata_request
         decoder = KafkaProtocol.decode_consumer_metadata_response
 
         return self._send_broker_unaware_request(payloads, encoder, decoder)
 
     @time_metric('produce')
-    def send_produce_request(self, payloads=[], acks=1, timeout=1000,
+    def send_produce_request(self, payloads=(), acks=1, timeout=1000,
                              fail_on_error=True, callback=None):
         """
         Encode and send some ProduceRequests
@@ -704,7 +704,7 @@ def send_produce_request(self, payloads=[], acks=1, timeout=1000,
                 (not fail_on_error or not self._raise_on_response_error(resp))]
 
     @time_metric('fetch')
-    def send_fetch_request(self, payloads=[], fail_on_error=True,
+    def send_fetch_request(self, payloads=(), fail_on_error=True,
                            callback=None, max_wait_time=100, min_bytes=4096):
         """
         Encode and send a FetchRequest
@@ -725,7 +725,7 @@ def send_fetch_request(self, payloads=[], fail_on_error=True,
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset')
-    def send_offset_request(self, payloads=[], fail_on_error=True,
+    def send_offset_request(self, payloads=(), fail_on_error=True,
                             callback=None):
         resps = self._send_broker_aware_request(
             payloads,
@@ -736,8 +736,8 @@ def send_offset_request(self, payloads=[], fail_on_error=True,
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset_list')
-    def send_list_offset_request(self, payloads=[], fail_on_error=True,
-                                callback=None):
+    def send_list_offset_request(self, payloads=(), fail_on_error=True,
+                            callback=None):
         resps = self._send_broker_aware_request(
             payloads,
             KafkaProtocol.encode_list_offset_request,
@@ -747,7 +747,7 @@ def send_list_offset_request(self, payloads=[], fail_on_error=True,
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset_commit')
-    def send_offset_commit_request(self, group, payloads=[],
+    def send_offset_commit_request(self, group, payloads=(),
                                    fail_on_error=True, callback=None):
         encoder = functools.partial(
             KafkaProtocol.encode_offset_commit_request,
@@ -760,7 +760,7 @@ def send_offset_commit_request(self, group, payloads=[],
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset_commit_kafka')
-    def send_offset_commit_request_kafka(self, group, payloads=[],
+    def send_offset_commit_request_kafka(self, group, payloads=(),
                                          fail_on_error=True, callback=None):
         encoder = functools.partial(
             KafkaProtocol.encode_offset_commit_request_kafka,
@@ -773,7 +773,7 @@ def send_offset_commit_request_kafka(self, group, payloads=[],
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset_fetch')
-    def send_offset_fetch_request(self, group, payloads=[],
+    def send_offset_fetch_request(self, group, payloads=(),
                                   fail_on_error=True, callback=None):
 
         encoder = functools.partial(KafkaProtocol.encode_offset_fetch_request,
@@ -785,7 +785,7 @@ def send_offset_fetch_request(self, group, payloads=[],
                 if not fail_on_error or not self._raise_on_response_error(resp)]
 
     @time_metric('offset_fetch_kafka')
-    def send_offset_fetch_request_kafka(self, group, payloads=[],
+    def send_offset_fetch_request_kafka(self, group, payloads=(),
                                   fail_on_error=True, callback=None):
 
         encoder = functools.partial(KafkaProtocol.encode_offset_fetch_request,

test/test_client.py

@@ -404,7 +404,7 @@ def test_send_produce_request_raises_when_topic_unknown(self, protocol, conn):
     def test_correlation_rollover(self):
         with patch.object(SimpleClient, 'load_metadata_for_topics'):
             big_num = 2**31 - 3
-            client = SimpleClient(hosts=[], correlation_id=big_num)
+            client = SimpleClient(hosts=(), correlation_id=big_num)
             self.assertEqual(big_num + 1, client._next_id())
             self.assertEqual(big_num + 2, client._next_id())
             self.assertEqual(0, client._next_id())

test/test_conn.py

@@ -112,7 +112,7 @@ def test_send_max_ifr(conn):
 def test_send_no_response(_socket, conn):
     conn.connect()
     assert conn.state is ConnectionStates.CONNECTED
-    req = ProduceRequest[0](required_acks=0, timeout=0, topics=[])
+    req = ProduceRequest[0](required_acks=0, timeout=0, topics=())
     header = RequestHeader(req, client_id=conn.config['client_id'])
     payload_bytes = len(header.encode()) + len(req.encode())
     third = payload_bytes // 3

test/test_fetcher.py

@@ -22,7 +22,7 @@
 
 @pytest.fixture
 def client(mocker):
-    return mocker.Mock(spec=KafkaClient(bootstrap_servers=[], api_version=(0, 9)))
+    return mocker.Mock(spec=KafkaClient(bootstrap_servers=(), api_version=(0, 9)))
 
 
 @pytest.fixture

test/test_sender.py

@@ -19,7 +19,7 @@
 
 @pytest.fixture
 def client(mocker):
-    _cli = mocker.Mock(spec=KafkaClient(bootstrap_servers=[], api_version=(0, 9)))
+    _cli = mocker.Mock(spec=KafkaClient(bootstrap_servers=(), api_version=(0, 9)))
     _cli.cluster = mocker.Mock(spec=ClusterMetadata())
     return _cli