Bug: get_parameters_by_name raises KeyError for names with a version or label selector #8587

Expected Behaviour

get_parameters_by_name({"/a:prod": {}}) returns the value of the prod label, like get_parameter("/a:prod") already does. Selectors (name:version, name:label) are valid input for the GetParameters API.

Current Behaviour

SSM returns the parameter with Name="/a" and Selector=":prod" (the selector is only the suffix, ":prod" or ":1", not the full requested name). _transform_and_cache_get_parameters_response (ssm.py:650) looks the returned Name up in the user's dict, which only has /a:prod, so it crashes with KeyError: '/a'. Real response for Names=["/p:prod", "/p:1", "/p"]:

[{"Name": "/p", "Selector": ":1",    "Value": "v1"},
 {"Name": "/p", "Selector": ":prod", "Value": "v1"},
 {"Name": "/p", "Selector": null,    "Value": "v2"}]

Code snippet

from unittest.mock import MagicMock
from botocore.config import Config
from aws_lambda_powertools.utilities.parameters import SSMProvider

provider = SSMProvider(boto_config=Config(region_name="us-east-1"))
# what SSM really returns for Names=["/a:prod"]: Name without the selector, Selector with it
provider.client.get_parameters = MagicMock(return_value={
    "Parameters": [{"Name": "/a", "Value": "v", "Selector": ":prod", "Type": "String", "Version": 1}],
    "InvalidParameters": [],
})

print(provider.get_parameters_by_name({"/a:prod": {}}))  # KeyError: '/a'   (provider.get("/a:prod") works)

Possible Solution

Rebuild the requested key as parameter["Name"] + parameter.get("Selector", "") and use it for the response and the cache.

Steps to Reproduce

Run the snippet above (a mocked client, no AWS access needed; botocore's Stubber rejects the empty InvalidParameters list that the real service returns).

Powertools for AWS Lambda (Python) version

latest

AWS Lambda function runtime

3.13

Packaging format used

PyPi

Debugging logs