SyntaxWarning: 'return' in a 'finally' block (Python 3.14)

Bắt đầu tại datadog_lambda/wrapper.py, ở _LambdaDecorator.call, và kiểm tra luồng điều khiển try/except/finally, đặc biệt là return được báo cáo ở dòng 203. Xác minh bốn đường dẫn thực thi được mô tả trong issue và thêm hoặc cập nhật các bài kiểm thử để việc import trên Python 3.14 không phát ra SyntaxWarning, đồng thời các response dạng blocking và thông thường vẫn chính xác.

Expected Behavior

No warnings emitted during Lambda cold start when importing datadog_lambda.

Actual Behavior

A SyntaxWarning is emitted at module import time (cold start) on Python 3.14:

/var/task/datadog_lambda/wrapper.py:203: SyntaxWarning: 'return' in a 'finally' block
  return self.blocking_response

This warning fires every cold start and pollutes CloudWatch logs. Python 3.14 introduced SyntaxWarning for return/break/continue inside finally blocks because such a return silently suppresses any exception that was actively propagating through the try/except.

Steps to Reproduce the Problem

1. Deploy a Lambda function using datadog-lambda on the Python 3.14 runtime
2. Trigger a cold start (first invocation or new sandbox)
3. Observe the SyntaxWarning in CloudWatch logs during INIT_START

Specifications

• Datadog Lambda Library version: 8.123.0
• Python version: 3.14

Root Cause

In _LambdaDecorator.__call__, the finally block contains a return:

finally:
    self._after(event, context)
    if self.blocking_response:
        return self.blocking_response  # ← triggers SyntaxWarning in Python 3.14

Proposed Fix

Remove return self.response from the try block and return self.blocking_response from the finally block, deferring both to after the entire try/except/finally:

    try:
        if self.blocking_response:
            return self.blocking_response
        self.response = self.func(event, context, **kwargs)
    except BlockingException:
        self.blocking_response = get_asm_blocked_response(self.event_source)
    except Exception:
        ...
        raise
    finally:
        self._after(event, context)

    if self.blocking_response:
        return self.blocking_response
    return self.response

All four execution paths (block before, block during, block after, normal) remain correct. Happy to open a PR with this fix and updated tests.

Stacktrace

/var/task/datadog_lambda/wrapper.py:203: SyntaxWarning: 'return' in a 'finally' block
return self.blocking_response