fix: fix datetime serilization for lambda invoker

- Use smithy datetime format for all serializer
- Refactor serilization for filesystem and web module
- Remove unused import
- Remove unused txt file
- More unit tests for web/server

Author: Alex Wang

src/aws_durable_execution_sdk_python_testing/invoker.py

@@ -12,14 +12,13 @@
     DurableExecutionInvocationInputWithClient,
     DurableExecutionInvocationOutput,
     InitialExecutionState,
-    InvocationStatus,
 )
 
 from aws_durable_execution_sdk_python_testing.exceptions import (
     DurableFunctionsTestError,
-    ServiceException,
 )
 from aws_durable_execution_sdk_python_testing.model import LambdaContext
+from aws_durable_execution_sdk_python_testing.serialization import DateTimeEncoder
 
 if TYPE_CHECKING:
     from collections.abc import Callable
@@ -239,7 +238,7 @@ def invoke(
             response = client.invoke(
                 FunctionName=function_name,
                 InvocationType="RequestResponse",  # Synchronous invocation
-                Payload=json.dumps(input.to_dict(), default=str),
+                Payload=json.dumps(input.to_dict(), cls=DateTimeEncoder),
             )
 
             # Check HTTP status code

…_sdk_python_testing/web/serialization.py …tion_sdk_python_testing/serialization.pysrc/aws_durable_execution_sdk_python_testing/web/serialization.py renamed to src/aws_durable_execution_sdk_python_testing/serialization.py src/aws_durable_execution_sdk_python_testing/web/serialization.py renamed to src/aws_durable_execution_sdk_python_testing/serialization.py

@@ -6,12 +6,11 @@
 
 from __future__ import annotations
 
-import json
 import os
+import json
 from typing import Any, Protocol
-from datetime import datetime
+from datetime import datetime, UTC
 
-import aws_durable_execution_sdk_python
 import botocore.loaders  # type: ignore
 from botocore.model import ServiceModel  # type: ignore
 from botocore.parsers import create_parser  # type: ignore
@@ -22,6 +21,31 @@
 )
 
 
+class DateTimeEncoder(json.JSONEncoder):
+    """Custom JSON encoder that converts datetime objects to millisecond timestamps, which match smithy encoding behaviour."""
+
+    def default(self, obj):
+        if isinstance(obj, datetime):
+            # seconds_float to milliseconds
+            return int(obj.timestamp() * 1000)
+        return super().default(obj)
+
+
+def datetime_object_hook(obj):
+    """JSON object hook to convert millisecond timestamps back to datetime objects."""
+    if isinstance(obj, dict):
+        for key, value in obj.items():
+            if isinstance(value, int | float) and key.endswith(
+                ("_timestamp", "_time", "Timestamp", "Time")
+            ):
+                try:  # noqa: SIM105
+                    obj[key] = datetime.fromtimestamp(value / 1000, tz=UTC)
+                except (ValueError, OSError):
+                    # Leave as number if not a valid timestamp
+                    pass
+    return obj
+
+
 class Serializer(Protocol):
     """Interface for serializing data to bytes."""
 
@@ -64,22 +88,13 @@ class JSONSerializer:
     def to_bytes(self, data: Any) -> bytes:
         """Serialize data to JSON bytes."""
         try:
-            json_string = json.dumps(
-                data, separators=(",", ":"), default=self._default_handler
-            )
+            json_string = json.dumps(data, separators=(",", ":"), cls=DateTimeEncoder)
             return json_string.encode("utf-8")
         except (TypeError, ValueError) as e:
             raise InvalidParameterValueException(
                 f"Failed to serialize data to JSON: {str(e)}"
             )
 
-    def _default_handler(self, obj: Any) -> float:
-        """Handle non-permitive objects."""
-        if isinstance(obj, datetime):
-            return obj.timestamp()
-        # Raise TypeError for unsupported types
-        raise TypeError(f"Object of type {type(obj).__name__} is not JSON serializable")
-
 
 class AwsRestJsonSerializer:
     """AWS rest-json serializer using boto."""

src/aws_durable_execution_sdk_python_testing/stores/filesystem.py

@@ -4,42 +4,21 @@
 
 import json
 import logging
-from datetime import UTC, datetime
 from pathlib import Path
 
 from aws_durable_execution_sdk_python_testing.exceptions import (
     ResourceNotFoundException,
 )
+from aws_durable_execution_sdk_python_testing.serialization import (
+    DateTimeEncoder,
+    datetime_object_hook,
+)
 from aws_durable_execution_sdk_python_testing.execution import Execution
 from aws_durable_execution_sdk_python_testing.stores.base import (
     BaseExecutionStore,
 )
 
 
-class DateTimeEncoder(json.JSONEncoder):
-    """Custom JSON encoder that handles datetime objects."""
-
-    def default(self, obj):
-        if isinstance(obj, datetime):
-            return obj.timestamp()
-        return super().default(obj)
-
-
-def datetime_object_hook(obj):
-    """JSON object hook to convert unix timestamps back to datetime objects."""
-    if isinstance(obj, dict):
-        for key, value in obj.items():
-            if isinstance(value, int | float) and key.endswith(
-                ("_timestamp", "_time", "Timestamp", "Time")
-            ):
-                try:  # noqa: SIM105
-                    obj[key] = datetime.fromtimestamp(value, tz=UTC)
-                except (ValueError, OSError):
-                    # Leave as number if not a valid timestamp
-                    pass
-    return obj
-
-
 class FileSystemExecutionStore(BaseExecutionStore):
     """File system-based execution store for persistence."""
 

src/aws_durable_execution_sdk_python_testing/stores/sqlite.py

@@ -17,7 +17,7 @@
 from aws_durable_execution_sdk_python_testing.stores.base import (
     ExecutionStore,
 )
-from aws_durable_execution_sdk_python_testing.stores.filesystem import (
+from aws_durable_execution_sdk_python_testing.serialization import (
     DateTimeEncoder,
     datetime_object_hook,
 )

src/aws_durable_execution_sdk_python_testing/web/models.py

@@ -14,7 +14,7 @@
 
 # Removed deprecated imports from web.errors
 from aws_durable_execution_sdk_python_testing.web.routes import Route
-from aws_durable_execution_sdk_python_testing.web.serialization import (
+from aws_durable_execution_sdk_python_testing.serialization import (
     AwsRestJsonDeserializer,
     JSONSerializer,
     Serializer,

tests/how-to-run-from-term.txt

@@ -12,6 +12,17 @@
     InvocationStatus,
 )
 
+from aws_durable_execution_sdk_python.lambda_service import (
+    ExecutionDetails,
+    Operation,
+    OperationStatus,
+    OperationType,
+)
+
+from aws_durable_execution_sdk_python_testing.serialization import DateTimeEncoder
+
+from datetime import datetime, UTC
+
 from aws_durable_execution_sdk_python_testing.execution import Execution
 from aws_durable_execution_sdk_python_testing.invoker import (
     InProcessInvoker,
@@ -168,10 +179,23 @@ def test_lambda_invoker_invoke_success():
 
     invoker = LambdaInvoker(lambda_client)
 
+    mock_operation = Operation(
+        operation_id="op-1",
+        parent_id=None,
+        name="test-execution",
+        start_timestamp=datetime.now(UTC),
+        end_timestamp=datetime.now(UTC),
+        operation_type=OperationType.EXECUTION,
+        status=OperationStatus.SUCCEEDED,
+        execution_details=ExecutionDetails(input_payload='{"test": "data"}'),
+    )
+
     input_data = DurableExecutionInvocationInput(
         durable_execution_arn="test-arn",
         checkpoint_token="test-token",  # noqa: S106
-        initial_execution_state=InitialExecutionState(operations=[], next_marker=""),
+        initial_execution_state=InitialExecutionState(
+            operations=[mock_operation], next_marker=""
+        ),
     )
 
     response = invoker.invoke("test-function", input_data)
@@ -185,7 +209,7 @@ def test_lambda_invoker_invoke_success():
     lambda_client.invoke.assert_called_once_with(
         FunctionName="test-function",
         InvocationType="RequestResponse",
-        Payload=json.dumps(input_data.to_dict(), default=str),
+        Payload=json.dumps(input_data.to_dict(), cls=DateTimeEncoder),
     )