DatetimeInterval Pydantic Model rendered incorrectly in FastAPI Generate Swagger Docs

[ciaransweet]

The DatetimeInterval Pydantic Model is rendered as an array<[string, string], any> in the generated SwaggerUI docs when using this type in stapi-fastapi

See its usage, pulled in via OrderPayload:

from stapi_pydantic import (
    OpportunityProperties,
    Order,
    OrderPayload,
    OrderStatusCode,
    Queryables,
)

from app.repositories import STAPIRepository
from app.schemas.stapi import OrderParameters as BaseOrderParameters


async def create_order(
    product_router: ProductRouter, payload: OrderPayload, request: Request
) -> ResultE[Order]:

create_order is then used in a Product and added via router.add_product(umbra.product)

On the SwaggerUI docs:

Which alludes to:

"datetime": ["2025-01-01T00:00:00Z", "2025-12-31T23:59:59Z"]

When actually it should be:

"datetime": "2025-01-01T00:00:00Z/2025-12-31T23:59:59Z"

Looks like Swagger is picking up the tuple[AwareDatetime, AwareDatetime], first, which isn't actually the expected input.

My guess is the tests give some false hope here: https://github.com/stapi-spec/pystapi/blob/main/stapi-fastapi/tests/test_order.py#L49-L61

as they're using the model to pass to the endpoint, which will have the serialisation performed.