Use SageMaker SDK's own string serializer/deserializer in tests

tests/test_inference_server.py

@@ -9,10 +9,8 @@
 # "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.
 
-from typing import Tuple
-
-import botocore.response
 import pytest
+import sagemaker.deserializers
 import sagemaker.serializers
 
 import inference_server
@@ -83,26 +81,12 @@ def test_invocations():
 
 def test_prediction_custom_serializer():
     """Test the default plugin again, now using high-level testing.predict"""
-
-    class Serializer(sagemaker.serializers.BaseSerializer):
-        @property
-        def CONTENT_TYPE(self) -> str:
-            return "application/octet-stream"
-
-        def serialize(self, data: str) -> bytes:
-            return data.encode()  # Simple str to bytes serializer
-
-    class Deserializer(sagemaker.deserializers.BaseDeserializer):
-        @property
-        def ACCEPT(self) -> Tuple[str]:
-            return ("application/json",)
-
-        def deserialize(self, stream: botocore.response.StreamingBody, content_type: str) -> str:
-            assert content_type in self.ACCEPT
-            return stream.read().decode()  # Simple bytes to str deserializer
-
     input_data = "What's the shipping forecast for tomorrow"  # Simply pass a string
-    prediction = inference_server.testing.predict(data=input_data, serializer=Serializer(), deserializer=Deserializer())
+    prediction = inference_server.testing.predict(
+        data=input_data,
+        serializer=sagemaker.serializers.StringSerializer(),
+        deserializer=sagemaker.deserializers.StringDeserializer(),
+    )
     assert prediction == input_data  # Receive a string