Seecr Testtools

Small helpers for writing pytest tests, used across Seecr projects.

Installation

pip install seecr-testtools

Requires Python 3.11 or newer. Installs pytest and pytest-asyncio.

What's inside

anything: wildcards in assertions

anything equals every value, so you can compare whole structures while ignoring the parts you don't care about. Pass a function to check a value instead of ignoring it.

from seecr_testtools import anything

assert response == {
    "id": anything,                           # any value
    "name": "Alice",
    "age": anything(lambda age: age >= 18),   # must satisfy the check
}

Mock: record calls and fake return values

from seecr_testtools.mock import Mock

store = Mock.blank(get={"a": 1}.get, save=None)
store.get("a")              # 1: a callable value is called
store.save(1, force=True)   # None: other values are returned as is
store.whatever()            # unknown methods return None
store.calls("save")         # [save(1, force=True)]
store.calls("save")[0].kwargs  # {'force': True}

Mock.imitate(obj) wraps a real object. Methods you override with mock_method are replaced on the object itself, so the object's own code calls the fake too. Coroutine methods automatically get an async fake.

class Repository:
    def load(self):
        return "from database"

    def report(self):
        return self.load().upper()

repo = Repository()
mock = Mock.imitate(repo)
mock.mock_method("load", "fake")

assert mock.report() == "FAKE"   # report() runs for real, load() is faked
assert len(mock.calls("load")) == 1

For a blank mock, use mock_method(name, value, is_async=True) to get an async method.

login_user

Logs a user in on a test client for Seecr web applications and keeps the session cookie: login_user(env, username, password). It expects env to provide client and actions.

Development

python -m venv env --prompt seecr-testtools
source env/bin/activate
pip install -e .
pytest

Tests live next to the code as <module>_test.py. Async tests need no decorator: pytest-asyncio runs in auto mode.

License

Copyright (C) 2024-2026 Seecr (Seek You Too B.V.)

Licensed under the MIT License.