Expected Behaviour Work as expected and described in the docs: <a

<p class="markdown-alert-title" dir=

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Bug: Event Handler Data Validation `KeyError: 'multiValueHeaders'` regression when running locally about powertools-lambda-python HOT 3 CLOSED

heitorlessa commented on August 9, 2024

Bug: Event Handler Data Validation `KeyError: 'multiValueHeaders'` regression when running locally

from powertools-lambda-python.

Comments (3)

heitorlessa commented on August 9, 2024

Important

This only happens locally or outside Lambda, and when Data Validation feature is used

Reported on Discord -- agreed with customer to work on a fix and make a patch release tomorrow, as it blocks customers from upgrading as unit tests are failing.

Our tests don't fail because multiValueHeaders are always present in the real but fake event.

Todo:

Update dataclasses property to not access a key directly to prevent KeyError
Create a functional test with minimal event as described in the docs to prevent regression like this

functional test

def test_validate_with_minimal_event():
    # GIVEN an APIGatewayRestResolver with validation enabled
    app = APIGatewayRestResolver(enable_validation=True)

    # WHEN a handler is defined with a default scalar parameter
    @app.get("/users/<user_id>")
    def handler(user_id: int = 123):
        print(user_id)

    minimal_event = {
        "path": "/users/123",
        "httpMethod": "GET",
        "requestContext": {"requestId": "227b78aa-779d-47d4-a48e-ce62120393b8"},  # correlation ID
    }

    # THEN the handler should be invoked and return 200
    result = app(minimal_event, {})
    assert result["statusCode"] == 200