APIGatewayProxyEvent json_body throws exception if no body

[bb-rrogers]

Heya All,

Not sure if this would be seen as an issue or not, but I thought I would log it anyways. When using the APIGatewayProxyEvent.json_body function I have found that if there is no body, it will throw a TypeError:
[ERROR] TypeError: the JSON object must be str, bytes or bytearray, not NoneType

I feel on the fence whether it's better to validate that there is a body before attempting to json_body but I guess with the return type hint being Any I was maybe expecting a None or empty string.

Expected Behavior

I expect the json_body should return an empty string if the object is not present in the payload

Current Behavior

Function throws a TypeError because json.loads cannot handle None objects.

Steps to Reproduce (for bugs)

app = ApiGatewayResolver()

@app.get("/test")
def get_test():
  app.current_event.json_body

def handler(event: dict, context: dict) -> dict:
    return app.resolve(event=event, context=context)

Including a REST request with an None body.

Again, not sure if this should be considered a bug or not, looking for guidance here, is a minor issue.

Environment

• Powertools version used: 1.22.0
• Packaging format (Layers, PyPi): Layers
• AWS Lambda function runtime: Python 3.9
• Debugging logs

[heitorlessa]

hey @bb-rrogers thanks a lot for raising this. We can indeed do a much better job here - I suspect we implicitly trust customers would only call as they know their payload better, however a type Any doesn't help .. despite JSON Values not having an actual agreement on a generic type in Python

[michaelbrewer]

@heitorlessa what should we be returning ?

[heitorlessa]

Return None if we can't decode, and update to Optional[Any].

MyPy used to be okay with Any also meaning a None, but that changed since an Union is safer (Optional[Any] == Union[T, None])

Thanks a lot @michaelbrewer

[bb-rrogers]

Thanks both. The intent was to stir up discussion here but through further reflection I think maybe it's better to keep it as is, I can see positives for and against but will let you guys ultimately decide. I just wanted to log this to figure out the reasoning here.

[heitorlessa]

Np- closing this then. We could spend the effort elsewhere like Idempotency serialisation to support dataclasses and Parser (Pydantic) models