[BUG] Future annotations breaks List[Link]

[dartt0n]

Describe the bug
When file with models contain from __future__ import annotations Link does not works as expected. Link nests a document instead of creating DbRef.

Reproducible example:

# models.py
from __future__ import annotations

from beanie import Document, Link
from pydantic import UUID4


class UserProfile(Document):
    projects: list[Link["Project"]]
    legacy_id: UUID4

    class Settings:
        name = "user_profile"


class Project(Document):
    user: Link["UserProfile"]
    legacy_id: UUID4

    class Settings:
        name = "project"

# main.py
import asyncio
from uuid import UUID, uuid4

import beanie
from motor.motor_asyncio import AsyncIOMotorClient

import models

users = [
    {"id": str(uuid4())},
    {"id": str(uuid4())},
    {"id": str(uuid4())},
]

projects = [
    {"id": str(uuid4()), "owner_id": users[0]["id"]},
    {"id": str(uuid4()), "owner_id": users[0]["id"]},
    {"id": str(uuid4()), "owner_id": users[1]["id"]},
    {"id": str(uuid4()), "owner_id": users[1]["id"]},
    {"id": str(uuid4()), "owner_id": users[2]["id"]},
    {"id": str(uuid4()), "owner_id": users[2]["id"]},
]


async def load_users() -> list[dict]:
    return users


async def load_projects() -> list[dict]:
    return projects


async def main():
    client = AsyncIOMotorClient("mongodb://localhost:27017")
    await beanie.init_beanie(client.test, document_models=[models.UserProfile, models.Project])

    for data in await load_users():
        user = models.UserProfile(
            projects=[],
            legacy_id=UUID(data["id"]),
        )
        await user.insert()

    for data in await load_projects():
        user = await models.UserProfile.find_one({"legacy_id": UUID(data["owner_id"])})
        assert user is not None

        project = models.Project(
            user=user.to_ref(),
            legacy_id=UUID(data["id"]),
        )
        await project.insert()

    for project in await models.Project.find_all().to_list():
        user = await models.UserProfile.find_one({"_id": project.user.ref.id})
        assert user is not None

        user.projects.append(project)
        await user.save()

if __name__ == "__main__":
    asyncio.run(main())

If I remove from __future__ import annotations line everything works as expected.

Expected behavior
It is expected that projects are saved as DbRef, meanwhile current behaviour clones document and nests it to the parent document. from __future__ import annotations should not have any effect on behaviour.

[github-actions]

This issue is stale because it has been open 30 days with no activity.

[dartt0n]

This problem is becoming more relevant, as in python 3.14 this behavior of FORWARDREF will become the default behavior. The bug is still present in the latest (1.29.0) release

[dartt0n]

Projects are nested inside user profiles (data duplication) instead of using DbRef