fix(parameters): accumulate results across chunks in get_parameters_by_name

[abhu85]

Issue # (if applicable)

Closes #7832

Summary

Fixes a variable shadowing bug in _get_parameters_by_name_in_chunks that caused get_parameters_by_name to return only the last chunk of parameters when fetching more than 10 parameters.

Root Cause

In the _get_parameters_by_name_in_chunks method, the loop variable response was being overwritten on each iteration instead of being accumulated:

# Before (buggy):
for chunk in slice_dictionary(data=diff, chunk_size=self._MAX_GET_PARAMETERS_ITEM):
    response, possible_errors = self._get_parameters_by_name(...)  # response overwritten!
    response.update(response)  # No-op: updating dict with itself
    errors.extend(possible_errors)

# After (fixed):
for chunk in slice_dictionary(data=diff, chunk_size=self._MAX_GET_PARAMETERS_ITEM):
    chunk_response, possible_errors = self._get_parameters_by_name(...)
    response.update(chunk_response)  # Accumulate results
    errors.extend(possible_errors)

Impact

When fetching more than 10 parameters with get_parameters_by_name, only the last chunk (up to 10 parameters) was returned. For example, fetching 12 parameters would only return the last 2 parameters instead of all 12.

Changes

1. aws_lambda_powertools/utilities/parameters/ssm.py: Fixed variable shadowing by renaming the loop variable from response to chunk_response

2. tests/functional/parameters/_boto3/test_utilities_parameters.py: Added test_get_parameters_by_name_accumulates_results_across_chunks to verify results are accumulated across chunks

Test Plan

• New test test_get_parameters_by_name_accumulates_results_across_chunks verifies all 12 parameters are returned when fetching more than 10
• All existing get_parameters_by_name tests pass (16 tests)
• Ruff linting passes on both modified files

Test Commands

# Run the new test
python -m pytest tests/functional/parameters/_boto3/test_utilities_parameters.py::test_get_parameters_by_name_accumulates_results_across_chunks -v

# Run all related tests
python -m pytest tests/functional/parameters/_boto3/test_utilities_parameters.py -k "get_parameters_by_name" -v

Acknowledgment

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud

[powertools-for-aws-oss-automation]

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[dreamorosi]

Superseded by #8006 - this PR is missing required metadata (see failing CI) and the test case was too verbose. I got my own Claude to generate a better one.

Thanks!