fix(idempotency): fix response hook invocation when function returns None

[leandrodamascena]

Issue number: #5150

Summary

Changes

This PR addresses an issue with the idempotency feature where the response hook is not called when the function returns None, even for idempotent requests.

Things changed:

• Modified idempotency logic to call the response hook for None returns.
• Add more functional tests
• Add more e2e tests

We don't need to change the documentation because this change fixes what should be the expected behavior.

User experience

import datetime
import os
import uuid
from typing import Dict

from aws_lambda_powertools import Logger
from aws_lambda_powertools.utilities.idempotency import (
    DynamoDBPersistenceLayer,
    IdempotencyConfig,
    idempotent_function,
)
from aws_lambda_powertools.utilities.idempotency.persistence.datarecord import (
    DataRecord,
)
from aws_lambda_powertools.utilities.typing import LambdaContext

logger = Logger(level="DEBUG")

def my_response_hook(response: Dict, idempotent_data: DataRecord) -> Dict:
    logger.info(f"Idempotent data", extra={"idempotent_data": idempotent_data, "response": response})
    
    # ...

    # Must return the response here
    return response


table = "IdempotencyTable"
dynamodb = DynamoDBPersistenceLayer(table_name=table)
config = IdempotencyConfig(response_hook=my_response_hook)

@idempotent_function(data_keyword_argument="order", config=config, persistence_store=dynamodb)
def process_order(order: dict) -> dict:
    logger.info(f"Processing order id {event.get('order_id')}")

    # return empty response
    return None


def lambda_handler(event: dict, context: LambdaContext):
    config.register_lambda_context(context)  # see Lambda timeouts section
    try:
        return process_order(order=event.get("order"))
    except Exception as err:
        return {"status_code": 400, "error": f"Error processing {str(err)}"}

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

Is this a breaking change?

RFC issue number:

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

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Disclaimer: We value your time and bandwidth. As such, any pull requests created on non-triaged issues might not be successful.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.21%. Comparing base (43da947) to head (a3caf68).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5251      +/-   ##
===========================================
- Coverage    96.21%   96.21%   -0.01%     
===========================================
  Files          229      229              
  Lines        10755    10753       -2     
  Branches      2003     2002       -1     
===========================================
- Hits         10348    10346       -2     
  Misses         321      321              
  Partials        86       86              

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[dreamorosi]

Thank you for fixing this, good also that you added new tests.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
1 Accepted issue

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud