Move conversion into the json converter to allow nested datetimes

Author: tconley1428

temporalio/converter.py

@@ -485,35 +485,6 @@ def from_payload(
             raise RuntimeError("Failed parsing") from err
 
 
-class ISO8601DatetimePayloadConverter(EncodingPayloadConverter):
-    """Converter for 'binary/iso8601' payloads supporting datetime values."""
-
-    @property
-    def encoding(self) -> str:
-        """See base class."""
-        return "binary/iso8601"
-
-    def to_payload(self, value: Any) -> Optional[temporalio.api.common.v1.Payload]:
-        """See base class."""
-        if isinstance(value, datetime):
-            return temporalio.api.common.v1.Payload(
-                metadata={"encoding": self.encoding.encode()},
-                data=value.isoformat().encode(),
-            )
-        return None
-
-    def from_payload(
-        self,
-        payload: temporalio.api.common.v1.Payload,
-        type_hint: Optional[Type] = None,
-    ) -> Any:
-        """See base class."""
-        try:
-            return datetime.fromisoformat(payload.data.decode())
-        except ValueError as err:
-            raise RuntimeError("Failed parsing ISO8601 datetime") from err
-
-
 class AdvancedJSONEncoder(json.JSONEncoder):
     """Advanced JSON encoder.
 
@@ -529,6 +500,9 @@ def default(self, o: Any) -> Any:
 
         See :py:meth:`json.JSONEncoder.default`.
         """
+        # Datetime support
+        if isinstance(o, datetime):
+            return o.isoformat()
         # Dataclass support
         if dataclasses.is_dataclass(o):
             return dataclasses.asdict(o)
@@ -1161,7 +1135,6 @@ async def decode_failure(
     BinaryPlainPayloadConverter(),
     JSONProtoPayloadConverter(),
     BinaryProtoPayloadConverter(),
-    ISO8601DatetimePayloadConverter(),
     JSONPlainPayloadConverter(),  # JSON Plain needs to remain in last because it throws on unknown types
 )
 
@@ -1429,6 +1402,15 @@ def value_to_type(
     # Any or primitives
     if hint is Any:
         return value
+    elif hint is datetime:
+        if isinstance(value, str):
+            try:
+                return _get_iso_datetime_parser()(value)
+            except ValueError as err:
+                raise TypeError(f"Failed parsing datetime string: {value}") from err
+        elif isinstance(value, datetime):
+            return value
+        raise TypeError(f"Expected datetime or ISO8601 string, got {type(value)}")
     elif hint is int or hint is float:
         if not isinstance(value, (int, float)):
             raise TypeError(f"Expected value to be int|float, was {type(value)}")

tests/test_converter.py

@@ -86,6 +86,11 @@ class MyDataClass:
     baz: SerializableEnum
 
 
+@dataclass
+class DatetimeClass:
+    datetime: datetime
+
+
 async def test_converter_default():
     async def assert_payload(
         input,
@@ -178,11 +183,28 @@ async def assert_payload(
         type_hint=RawValue,
     )
 
+    # Without type hint, it is deserialized as a str
+    await assert_payload(
+        datetime(2020, 1, 1, 1, 1, 1),
+        "json/plain",
+        '"2020-01-01T01:01:01"',
+        expected_decoded_input="2020-01-01T01:01:01",
+    )
+
+    # With type hint, it is deserialized as a datetime
     await assert_payload(
-        datetime(2020, 1, 1, 1, 1, 1), "binary/iso8601", "2020-01-01T01:01:01"
+        datetime(2020, 1, 1, 1, 1, 1, 1),
+        "json/plain",
+        '"2020-01-01T01:01:01.000001"',
+        type_hint=datetime,
     )
+
+    # Data class with datetime
     await assert_payload(
-        datetime(2020, 1, 1, 1, 1, 1, 1), "binary/iso8601", "2020-01-01T01:01:01.000001"
+        DatetimeClass(datetime=datetime(2020, 1, 1, 1, 1, 1)),
+        "json/plain",
+        '{"datetime":"2020-01-01T01:01:01"}',
+        type_hint=DatetimeClass,
     )