Bug: APIGatewayProxyEventV2.decoded_body should not cause KeyError

[aahung]

Expected Behaviour

For event of type APIGatewayProxyEventV2, event.decoded_body or event.json_body (which calls the former) could result in KeyError when there is no body.

Current Behaviour

Code snippet

`event.decoded_body` or `event.json_body`

Possible Solution

• event.decoded_body should return empty string or None
• event.json_body should raise JSONDecodeError

Steps to Reproduce

As described.

Powertools for AWS Lambda (Python) version

latest

AWS Lambda function runtime

3.11

Packaging format used

PyPi

Debugging logs

No response

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.
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[leandrodamascena]

Hey @aahung! Thanks for reporting this bug. You're right, we should use body: str = self.body instead of body: str = self["body"] in this line https://github.com/aws-powertools/powertools-lambda-python/blob/develop/aws_lambda_powertools/utilities/data_classes/common.py#L149.

Do you want to send a PR to fix this? We would love it.

Thanks

[heitorlessa]

Hi @aahung could you share how you ended up with the body key missing in the first place? Was this an actual request from API Gateway HTTP API, or a fake event?

Thank you

[isaacasancheza]

Hello there,

In my case it's an actual request from API Gateway HTTP API. Sending a POST without body throws the error (in my case using Postman with Body as none). I'm using aws_lambda_powertools.event_handler.APIGatewayHttpResolver with enable_validation=True.

Traceback (most recent call last):
  File "/opt/python/aws_lambda_powertools/event_handler/api_gateway.py", line 2002, in _call_route
    route(router_middlewares=self._router_middlewares, app=self, route_arguments=route_arguments),
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/event_handler/api_gateway.py", line 400, in __call__
    return self._middleware_stack(app)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/event_handler/api_gateway.py", line 1291, in __call__
    return self.current_middleware(app, self.next_middleware)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/event_handler/middlewares/base.py", line 121, in __call__
    return self.handler(app, next_middleware)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/event_handler/middlewares/openapi_validation.py", line 117, in handler
    received_body=self._get_body(app),
                  ^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/event_handler/middlewares/openapi_validation.py", line 243, in _get_body
    return app.current_event.json_body
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/lang/lib/python3.12/functools.py", line 995, in __get__
    val = self.func(instance)
          ^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/utilities/data_classes/common.py", line 153, in json_body
    return self._json_deserializer(self.decoded_body)
                                   ^^^^^^^^^^^^^^^^^
  File "/var/lang/lib/python3.12/functools.py", line 995, in __get__
    val = self.func(instance)
          ^^^^^^^^^^^^^^^^^^^
  File "/opt/python/aws_lambda_powertools/utilities/data_classes/common.py", line 158, in decoded_body
    body: str = self["body"]
                ~~~~^^^^^^^^
  File "/opt/python/aws_lambda_powertools/utilities/data_classes/common.py", line 32, in __getitem__
    return self._data[key]
           ~~~~~~~~~~^^^^^
KeyError: 'body'