pytest-beartype-tests 2026.4.20

Pytest plugin that applies @beartype to every collected test function.

A tiny pytest plugin that applies beartype to every collected test function, giving you runtime type-checking of test signatures and any locally-typed variables inside the test body.

This is distinct from pytest-beartype, which beartypes your source packages. This plugin beartypes the tests themselves.

Note

This plugin is a temporary workaround until pytest-beartype 0.3.0 is released, which is expected to provide this functionality natively (see https://github.com/beartype/pytest-beartype/issues/22). Once that release is available, you can migrate off this plugin.

Install

uv add --dev pytest-beartype-tests

The plugin auto-registers via the pytest11 entry point — there is no configuration.

What it does

Equivalent to writing this hook in your conftest.py:

import pytest
from beartype import beartype


def pytest_collection_modifyitems(items: list[pytest.Function]) -> None:
    for item in items:
        item.obj = beartype(obj=item.obj)