APIGateway event openAPI generation - multiValueQueryStringParameters validation

[MCR2019]

When an event from APIGatway contains a path parameter or query parameter these can be specified and validated using aws_lambda_powertools.event_handler.openapi.params Path and Query (and the openAPI spec generated).

If an event contains multiValueQueryStringParameters then I cannot see any way to specify, validate and access these? (and have them generated for the openAPI spec).

I've been unable to find anything in the documentation or code or get anything to work.

The following code is a starting point to demonstrate what I'm looking for (it doesn't work as I have used Query rather than something to specify multi value query parameters).

from enum import Enum
from http import HTTPStatus

from aws_lambda_powertools.event_handler import APIGatewayRestResolver
from aws_lambda_powertools.event_handler.openapi.params import Query
from aws_lambda_powertools.shared.types import Annotated
from aws_lambda_powertools.utilities.typing import LambdaContext

app = APIGatewayRestResolver(enable_validation=True)


class ExampleEnum(Enum):
    """Example of an Enum class."""

    ONE = "value_one"
    TWO = "value_two"
    THREE = "value_three"


@app.get("/example-resource")
def get(
    example_multi_value_param: Annotated[
        ExampleEnum,
        Query(
            description="This should be a multi value query parameter."
        ),  # TODO: How should this represent multi-value query string parameters?
    ]
):
    """Return validated multi-value param values."""
    return example_multi_value_param


def lambda_handler(event: dict, context: LambdaContext):
    """Handler to route API Gateway events."""
    return app.resolve(event, context)


class TestGetExample:
    def test_multi_param_call(self):
        """Get call with multi value param."""
        get_event = {
            "path": "/example-resource",
            "httpMethod": "GET",
            "queryStringParameters": {"example_multi_value_param": "value_three"},
            "multiValueQueryStringParameters": {"example_multi_value_param": ["value_one", "value_two", "value_three"]},
        }
        example_response = lambda_handler(event=get_event, context=LambdaContext)

        assert example_response["statusCode"] == HTTPStatus.OK
        assert example_response["body"] == ["value_one", "value_two", "value_three"]

I'd be interested in any thoughts on this :)

[leandrodamascena]

Hello @MCR2019! Thanks for always bringing up interesting points about our OpenAPI schema support.

This code should be something like this, but I get a 422 when trying to pass the same parameter multiple times to create the multiValue.

@rubenfonseca we need your help here.

@app.get("/example-resource")
def get(
    example_multi_value_param: Annotated[
        List[ExampleEnum],
         Query(
             description="This should be a multi value query parameter."
         ),  # TODO: How should this represent multi-value query string parameters?
    ]
):
    """Return validated multi-value param values."""
    return {"return": example_multi_value_param}

[rubenfonseca]

Please open a bug report on this one, we need to fix this use case. Thank you for reporting this!

[leandrodamascena]

Hey @rubenfonseca!