youtype/mypy_boto3_builder

Incorrect return type for boto3.session.Session.events

Closed this issue · 3 comments

nint8835 commented

Describe the bug
Currently, this package defines the return type of boto3.session.Session.events as List[Any]. This causes issues if you go to pass this as the event_handler arg to a botocore function, as they expect to get a BaseEventHooks.

As far as I can tell, BaseEventHooks is what the return type should be, as it's returning the event_handler component which is instantiated as either BaseEventHooks or a subclass of it within botocore

To Reproduce
Steps to reproduce the behavior:

  1. Install boto3-stubs[sts]
  2. Run mypy/pyright on the following code sample
import boto3
from botocore.signers import RequestSigner

session = boto3.session.Session()
client = session.client("sts", region_name="ca-central-1")
service_id = client.meta.service_model.service_id

signer = RequestSigner(
    service_id,
    "ca-central-1",
    "sts",
    "v4",
    session.get_credentials(),
    session.events,
)

(based on this sample from AWS)

Actual output

error: Argument 6 to "RequestSigner" has incompatible type "List[Any]"; expected "BaseEventHooks"  [arg-type]

Expected output

No issues found

Additional context
Occurs on the latest versions of boto3 (1.26.102), botocore (1.29.102), boto3-stubs (1.26.102), and botocore-stubs (1.29.102) as of time of writing.

vemel commented

Thanks for the report.

Looks like type annotations for RequestSigner are correct:

    :type event_emitter: :py:class:`~botocore.hooks.BaseEventHooks`
    :param event_emitter: Extension mechanism to fire events.

So it must be Session.events type annotation. I will try to fix it ASAP.

vemel commented

@nint8835 Fixed in boto3-stubs 1.26.103.post1. Please update and let me know if it works for you as expected.

nint8835 commented

From a quick test looks good to me - thanks for the quick fix!

  • 👍1