Improvements from code review

Author: dandavison

temporalio/converter.py

@@ -353,6 +353,9 @@ def __init__(self, *converters: EncodingPayloadConverter) -> None:
             converters: Payload converters to delegate to, in order.
         """
         self._set_converters(*converters)
+        self._any_converter_takes_context = any(
+            isinstance(c, WithSerializationContext) for c in converters
+        )
 
     def _set_converters(self, *converters: EncodingPayloadConverter) -> None:
         self.converters = {c.encoding.encode(): c for c in converters}
@@ -433,11 +436,13 @@ def with_context(self, context: SerializationContext) -> Self:
 
     def get_converters_with_context(
         self, context: SerializationContext
-    ) -> Optional[List[EncodingPayloadConverter]]:
+    ) -> Optional[list[EncodingPayloadConverter]]:
         """Return converter instances with context set.
 
         If no converter uses context, return None.
         """
+        if not self._any_converter_takes_context:
+            return None
         converters: list[EncodingPayloadConverter] = []
         any_with_context = False
         for c in self.converters.values():

temporalio/worker/_workflow.py

@@ -288,7 +288,7 @@ async def _handle_activation(
                 else:
                     payload_codec = _CommandAwarePayloadCodec(
                         workflow.instance,
-                        self._data_converter.payload_codec,
+                        context_free_payload_codec=self._data_converter.payload_codec,
                     )
                 await temporalio.bridge.worker.decode_activation(
                     act,
@@ -363,7 +363,7 @@ async def _handle_activation(
         if self._data_converter.payload_codec and workflow:
             payload_codec = _CommandAwarePayloadCodec(
                 workflow.instance,
-                self._data_converter.payload_codec,
+                context_free_payload_codec=self._data_converter.payload_codec,
             )
             try:
                 await temporalio.bridge.worker.encode_completion(