[BUG] python-fastapi: pytest fails

Description

pytest fails as follows:

#16 0.795 =================================== FAILURES ===================================
#16 0.795 _______________________________ test_place_order _______________________________
#16 0.795
#16 0.795 client = <starlette.testclient.TestClient object at 0x7f085de03210>
#16 0.795
#16 0.795 def test_place_order(client: TestClient):
#16 0.795 """Test case for place_order
#16 0.795
#16 0.795 Place an order for a pet
#16 0.795 """
#16 0.795 > body = openapi_server.Order()
#16 0.795 E NameError: name 'openapi_server' is not defined
#16 0.795
#16 0.795 tests/test_store_api.py:69: NameError

openapi-generator version

5.2.1

OpenAPI declaration file content or url

https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml

Generation Details

Run: docker run --rm -v ${PWD}:/local openapitools/openapi-generator-cli:v5.2.1 generate -i /local/openapi.yaml -g python-fastapi -o /local

Steps to reproduce

Run: docker-compose up (or docker-compose build --no-cache)

Related issues/PRs

None

Suggest a fix

Remove openapi_server. and add .dict() in the generated test code, for example:

Original:

    body = openapi_server.Order()

Modification:

    body = Order().dict()

Reproduce the failure with the documented docker-compose command, then inspect the generated tests/test_store_api.py and its test_place_order entry point. Compare the generated model construction with the python-fastapi output from the petstore.yaml declaration; done means the generated test imports correctly and pytest passes.