chore(logger): overload inject_lambda_context with generics

[ascopes]

Issue number: #1711

Summary

Changes

This enables static-type checking correctly with mypy when using pydantic models for the lambda event argument rather than a mapping type. Currently using this decorator results in an error and requires a typing ignore directive on the line using the decorator.

User experience

Before - using Pydantic models with lambda handlers produces a static typing error if
the @inject_lambda_context decorator is used.

After - the callable passed in is treated as a generic type and this generic flag is retained as the decorator return value, providing the same semantics that the tracer decorators do. This should enable MyPy to handle these constraints correctly.

Checklist

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• Meet tenets criteria
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented
• PR title follows conventional commit semantics

This should not be a breaking change other than places where invalid types or signatures may have been used previously.

Acknowledgment

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[boring-cyborg]

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[github-actions]

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[heitorlessa]

hey @ascopes, thank you for sending this improvement - would you be able to create an static typing issue to report the Mypy error, etc.?

We'd need an issue before proceeding - happy to do talk next week if you can't. We've also made the decision to bring typing-extensions as a dependency in upcoming releases -- this means we can now use the ParamSpec and more accurate annotations to preserve Callable signatures. Feel free to add them in as part of the PR.

Thanks a lot!

[ascopes]

Will try and dig the error out tomorrow if I have time. Thanks for the response!

[heitorlessa]

Created issue #1711 - I'll resolve the conflict, and push a change to use the new ParamSpec for more accurate typing now that we can use it 🙌

[codecov-commenter]

Codecov Report

Base: 99.27% // Head: 99.27% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (d0156c1) compared to base (9f3d748).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1583   +/-   ##
========================================
  Coverage    99.27%   99.27%           
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  Files          129      129           
  Lines         6054     6055    +1     
  Branches       402      402           
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+ Hits          6010     6011    +1     
  Misses          20       20           
  Partials        24       24           

Impacted Files	Coverage Δ
aws_lambda_powertools/logging/logger.py	99.39% <100.00%> (+<0.01%)	⬆️

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[heitorlessa]

Turns out partial isn't supported in ParamSpec, casting + narrowing return results into deeper issues that I can't dedicate time yet (narrow types for decorator factory for test code below).

Merging as-is. Thanks a lot for the patience @ascopes !

---

Test code for mypy which overrides event earlier than logger decorator

from aws_lambda_powertools import Logger
from aws_lambda_powertools.utilities.data_classes import event_source
from aws_lambda_powertools.utilities.data_classes.kinesis_stream_event import KinesisStreamEvent


logger = Logger()


@logger.inject_lambda_context
@event_source(data_class=KinesisStreamEvent)
def simple_handler(event: KinesisStreamEvent, context) -> str:
    return "success"


payload = {
    "Records": [
        {
            "kinesis": {
                "kinesisSchemaVersion": "1.0",
                "partitionKey": "da10bf66b1f54bff5d96eae99149ad1f",
                "sequenceNumber": "49635052289529725553291405521504870233219489715332317186",
                "data": "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",
                "approximateArrivalTimestamp": 1668093033.744,
            },
            "eventSource": "aws:kinesis",
            "eventVersion": "1.0",
            "eventID": "shardId-000000000000:49635052289529725553291405521504870233219489715332317186",
            "eventName": "aws:kinesis:record",
            "invokeIdentityArn": "arn:aws:iam::231436140809:role/pt-1488-CloudWatchKinesisLogsFunctionRole-1M4G2TIWIE49",
            "awsRegion": "eu-west-1",
            "eventSourceARN": "arn:aws:kinesis:eu-west-1:231436140809:stream/pt-1488-KinesisStreamCloudWatchLogs-D8tHs0im0aJG",
        },
        {
            "kinesis": {
                "kinesisSchemaVersion": "1.0",
                "partitionKey": "cf4c4c2c9a49bdfaf58d7dbbc2b06081",
                "sequenceNumber": "49635052289529725553291405520881064510298312199003701250",
                "data": "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",
                "approximateArrivalTimestamp": 1668092612.992,
            },
            "eventSource": "aws:kinesis",
            "eventVersion": "1.0",
            "eventID": "shardId-000000000000:49635052289529725553291405520881064510298312199003701250",
            "eventName": "aws:kinesis:record",
            "invokeIdentityArn": "arn:aws:iam::231436140809:role/pt-1488-CloudWatchKinesisLogsFunctionRole-1M4G2TIWIE49",
            "awsRegion": "eu-west-1",
            "eventSourceARN": "arn:aws:kinesis:eu-west-1:231436140809:stream/pt-1488-KinesisStreamCloudWatchLogs-D8tHs0im0aJG",
        },
    ]
}


ret: str = simple_handler(payload, object())

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!