Project Non-Goals

Karva is intentionally narrower than pytest. The goal is not to run every pytest suite unchanged; the goal is a fast, explicit test runner with a smaller surface area.

This page documents features Karva does not plan to support. If a feature is not listed here, that does not mean it is planned.

Class-Based Tests

Karva will not collect or run class-based tests.

Unsupported patterns include:

• class TestSomething: with test_* methods
• unittest.TestCase subclasses
• xUnit-style setup_method, teardown_method, setup_class, and teardown_class
• class-scoped fixture behavior

Use module-level test functions and fixtures instead:

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import karva


@karva.fixture
def service():
    return Service()


def test_service_handles_empty_input(service):
    assert service.handle("") == []

Classes are still fine as application code or local helpers inside tests. Only classes as the test structure are out of scope.

Pytest Request Internals

Karva will not expose pytest's request fixture or the FixtureRequest API.

Unsupported patterns include:

• request.param
• request.getfixturevalue(...)
• request.addfinalizer(...)
• request.node, request.config, and other pytest collection internals
• pytestconfig
• pytest_generate_tests

Use explicit fixture dependencies, generator fixtures, and normal configuration inputs instead:

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import karva


@karva.fixture
def database():
    db = connect()
    yield db
    db.close()


def test_query(database):
    assert database.query("select 1") == 1

Pytest Plugin Compatibility

Karva will not implement pytest's plugin or hook system as a compatibility layer. Pytest plugins depend on pytest's collection tree, config object, request object, and hook lifecycle, which are not part of Karva's design.

Karva can still provide first-party features inspired by common pytest plugins when they fit the project. Those features should be designed as Karva features, not as pytest plugin emulation.