pytest¶

Built-in pytest plugin (Injected parameters)¶

diwire ships with an optional pytest plugin that resolves parameters annotated as Annotated[T, Injected()] from a container.

Enable it in a test module or conftest.py:

pytest_plugins = ["diwire.integrations.pytest_plugin"]

Then annotate parameters:

from typing import Annotated

from diwire import Injected

def test_example(service: Annotated["Service", Injected()]) -> None:
    assert service is not None

Customizing the container¶

The plugin uses a diwire_container fixture. Override it to register fakes and test-specific configuration:

import pytest

from diwire import Container, Lifetime


@pytest.fixture()
def diwire_container() -> Container:
    container = Container(autoregister=False)
    container.register(Service, concrete_class=FakeService, lifetime=Lifetime.SINGLETON)
    return container

Scopes for injected dependencies¶

By default, injected dependencies are resolved inside container.enter_scope("test_function").

You can configure the scope name in four ways (highest priority first):

@pytest.mark.diwire_scope("my_scope") (or None to disable scoping for a single test)
CLI option: --diwire-scope my_scope
Override the diwire_scope fixture (per test module / conftest)
diwire_scope ini value (default is test_function)

Example (ini):

[tool.pytest.ini_options]
diwire_scope = "request"

To disable scoping entirely:

import pytest


@pytest.fixture()
def diwire_scope() -> str | None:
    return None

Notes¶

The plugin removes injected parameters from pytest’s fixture signature so normal fixture discovery still works.
The plugin is loaded via pytest_plugins; it is not auto-registered.

Container fixture¶

import pytest

from diwire import Container


@pytest.fixture
def container() -> Container:
    # Prefer a fresh container per test.
    return Container()

Using container_context in tests¶

If your app uses diwire.container_context, set/reset it in a fixture:

import pytest

from diwire import Container, container_context


@pytest.fixture
def container() -> Container:
    container = Container()
    token = container_context.set_current(container)
    try:
        yield container
    finally:
        container_context.reset(token)

Cleaning up scopes¶

Prefer with container.enter_scope(...): in tests so scope cleanup is deterministic. If you create scopes imperatively, close them (or call diwire.Container.close()) in teardown.