examples: Add none response examples

Author: Alex Wang

examples/examples-catalog.json

@@ -334,6 +334,17 @@
         "ExecutionTimeout": 300
       },
       "path": "./src/handler_error/handler_error.py"
+    },
+    {
+      "name": "None Results",
+      "description": "Test handling of step operations with undefined result after replay.",
+      "handler": "none_results.handler",
+      "integration": true,
+      "durableConfig": {
+        "RetentionPeriodInDays": 7,
+        "ExecutionTimeout": 300
+      },
+      "path": "./src/none_results/none_results.py"
     }
   ]
 }

examples/src/none_results/none_results.py

@@ -0,0 +1,31 @@
+"""Demonstrates handling of operations that return undefined values during replay."""
+
+from typing import Any
+
+from aws_durable_execution_sdk_python.context import (
+    DurableContext,
+    durable_with_child_context,
+)
+from aws_durable_execution_sdk_python.execution import durable_execution
+from aws_durable_execution_sdk_python.config import Duration
+
+
+@durable_with_child_context
+def parent_context(ctx: DurableContext) -> None:
+    """Parent context that returns None."""
+    return None
+
+
+@durable_execution
+def handler(_event: Any, context: DurableContext) -> str:
+    """Handler demonstrating operations with undefined/None results."""
+    context.step(
+        lambda _: None,
+        name="fetch-user",
+    )
+
+    context.run_in_child_context(parent_context(), name="parent")
+
+    context.wait(Duration.from_seconds(1), name="wait")
+
+    return "result"

examples/test/none_results/test_none_results.py

@@ -0,0 +1,51 @@
+"""Tests for undefined_results."""
+
+import pytest
+from aws_durable_execution_sdk_python.execution import InvocationStatus
+
+from src.none_results import none_results
+from test.conftest import deserialize_operation_payload
+
+
+@pytest.mark.example
+@pytest.mark.durable_execution(
+    handler=none_results.handler,
+    lambda_function_name="None Results",
+)
+def test_handle_step_operations_with_undefined_result_after_replay(durable_runner):
+    """Test handling of step operations with undefined result after replay."""
+    with durable_runner:
+        result = durable_runner.run(input=None, timeout=10)
+
+    assert result.status is InvocationStatus.SUCCEEDED
+
+    # Verify execution completed successfully despite undefined operation results
+    assert deserialize_operation_payload(result.result) == "result"
+
+    # Verify all operations were tracked even with undefined results
+    operations = result.operations
+    assert len(operations) == 3  # step + context + wait
+
+    # Verify step operation with undefined result
+    step_ops = [
+        op
+        for op in operations
+        if op.operation_type.value == "STEP" and op.name == "fetch-user"
+    ]
+    assert len(step_ops) == 1
+    step_op = step_ops[0]
+    assert deserialize_operation_payload(step_op.result) is None
+
+    # Verify child context operation with undefined result
+    context_ops = [
+        op
+        for op in operations
+        if op.operation_type.value == "CONTEXT" and op.name == "parent"
+    ]
+    assert len(context_ops) == 1
+    context_op = context_ops[0]
+    assert deserialize_operation_payload(context_op.result) is None
+
+    # Verify wait operation completed normally
+    wait_op = operations[2]
+    assert wait_op.operation_type.value == "WAIT"