[Bug]: invoke() returns None due to incorrect key name in ChainedInvokeDetails deserialization

[alessandrobologna]

Expected Behavior

When using context.invoke() to call a Lambda function that returns a response, the result should be properly deserialized and returned to the caller.

Actual Behavior

The invoke() function always returns None even when the invoked Lambda function returns a valid response. The result is lost during deserialization.

Steps to Reproduce

1. Create a durable function that uses context.invoke() to call another Lambda function
2. The target Lambda function returns a response (e.g., {"status": "success"})
3. The result of context.invoke() is None instead of the expected response

Root Cause

I suspect that this is the issue:
In src/aws_durable_execution_sdk_python/lambda_service.py, the Operation.from_dict() method at line 752 uses the wrong key name to deserialize ChainedInvokeDetails:

# Current (incorrect) - uses snake_case
if chained_invoke_details := data.get("chained_invoke_details"):

# Should be (correct) - uses PascalCase to match the API response
if chained_invoke_details := data.get("ChainedInvokeDetails"):

All other detail fields use PascalCase correctly:

• data.get("StepDetails") ✓
• data.get("WaitDetails") ✓
• data.get("CallbackDetails") ✓
• data.get("chained_invoke_details") ✗ (should be "ChainedInvokeDetails")

The to_dict() method correctly uses "ChainedInvokeDetails" (PascalCase) at line 826, confirming this is a bug in deserialization only.

The JavaScript SDK does not have this issue as it uses the Operation type directly from @aws-sdk/client-lambda.

SDK Version

0.1.0 (current main branch)

Python Version

3.12

Is this a regression?

No

Additional Context

The fix is a one-line change in lambda_service.py:752:

- if chained_invoke_details := data.get("chained_invoke_details"):
+ if chained_invoke_details := data.get("ChainedInvokeDetails"):