pytest-persistence

Pytest plugin for persistent fixtures.

Installation

In a Python environment do:

python -m pip install pytest-persistence

Usage

To store fixtures to file run tests with --store {file_path}:

python -m pytest --store {file_path}

To load fixtures from file run tests with --load {file_path}:

python -m pytest --load {file_path}

BEWARE When this plugin is in use cleanup of all the fixtures is not executed. This is necessary to successfully run tests with --load. However it is important to keep this fact in mind.

Excluding Fixtures

You can exclude specific fixtures from persistence using the @pytest_persistence.exclude decorator:

import pytest
import pytest_persistence

@pytest_persistence.exclude
@pytest.fixture
def non_persistent_fixture():
    return expensive_operation()

When a fixture is excluded:

• It will not be stored during --store
• It will be recreated during --load (parent fixtures will be loaded from file)
• All dependent fixtures are automatically excluded
• A warning is shown for implicitly excluded fixtures

Example with Dependencies

import pytest
from pytest_persistence import exclude

@exclude
@pytest.fixture
def excluded_fixture():
    return "excluded"

@pytest.fixture
def dependent_fixture(excluded_fixture):
    return f"depends on {excluded_fixture}"

@pytest.fixture  
def another_dependent(dependent_fixture):
    return f"also depends: {dependent_fixture}"

When running with --store, you'll see:

Warning: Fixture 'dependent_fixture' excluded due to dependency on excluded fixture 'excluded_fixture'
Warning: Fixture 'another_dependent' excluded due to dependency on excluded fixture 'dependent_fixture'