Type Annotations Support

Wireup supports string type annotations and from __future__ import annotations when the eval_type_backport package is installed.

Important Requirements

1. Define services and factories at the module level only. Inner function definitions are not supported.
2. Keep type imports accessible at runtime - don't move them to TYPE_CHECKING blocks.

Example

from typing import TYPE_CHECKING  # Don't do this!

if TYPE_CHECKING:
    from collections.abc import Iterator


@service
def create_thing() -> Iterator[Thing]:  # This needs the import at runtime
    yield Thing()

@service
@dataclass
class Service:
    thing: Thing  # This too needs the import at runtime

Warning

If you use Ruff/flake8 with rules like TCH, be careful not to move required imports into TYPE_CHECKING blocks.