#181 - ensure bytes are always returned from .body() method

[nathanglover]

I believe this closes #181.

All tests pass, and I have tested the solution on a live lambda function being severed by ALB.

The type annotations suggest that def body(self) -> bytes: should ALWAYS return bytes. However the code (and tests) sometimes returns None. In these cases I forced the None to return an empty byte string: b"". As a result most of the methods now look like this:

    @property
    def body(self) -> bytes:
        body = self.trigger_event.get("body", b"")

        if not body:
            body = b""
        if self.trigger_event.get("isBase64Encoded", False):
            return base64.b64decode(body)
        if not isinstance(body, bytes):
            body = body.encode()

        return body

If that is incorrect I can update my PR to reflect that bytes OR None can be returned from def body(self) and remove the code that forces None to become b"".

Let me know if I should add anything else! Have loved using Mangum these past few months, made moving my Django application to serverless pretty easy.

[jordaneremieff]

Hi @nathanglover, thanks for the PR!

Yep, you're right. Before the recent refactoring this was handled like this:

is_binary = event.get("isBase64Encoded", False)
body = event.get("body") or b""
if is_binary:
    body = base64.b64decode(body)
elif not isinstance(body, bytes):
    body = body.encode()

The intent of the or in body = event.get("body") or b"" was for handling this case. Could you update your PR to do body = self.trigger_event.get("body") or b"" to replace the additional if statement?

Then I think this is good to merge, thank you.

[nathanglover]

@jordaneremieff You're welcome. Removed the extra if and added the or as you asked. That way is a bit cleaner.

[jordaneremieff]

@nathanglover great, thanks!