Function _merge_lifespan_context

fastapi/routing.py:225–239

(
    original_context: Lifespan[Any], nested_context: Lifespan[Any]
)

def _merge_lifespan_context(
    original_context: Lifespan[Any], nested_context: Lifespan[Any]
) -> Lifespan[Any]:
    @asynccontextmanager
    async def merged_lifespan(
        app: AppType,
    ) -> AsyncIterator[Mapping[str, Any] | None]:
        async with original_context(app) as maybe_original_state:
            async with nested_context(app) as maybe_nested_state:
                if maybe_nested_state is None and maybe_original_state is None:
                    yield None  # old ASGI compatibility
                else:
                    yield {**(maybe_nested_state or {}), **(maybe_original_state or {})}

    return merged_lifespan  # type: ignore[return-value]  # ty: ignore[invalid-return-type]


class _DefaultLifespan: