pytest-fixture-config

Common errors

• ModuleNotFoundError: No module named 'pytest_fixture_config'

  cause The `pytest-fixture-config` package is not installed or not accessible in the current Python environment.
  fix Run `pip install pytest-fixture-config` to install the package.

• pytest.FixtureNotFound: Fixture 'my_config_fixture' not found

  cause A test or another fixture is requesting a fixture that either isn't defined, is misspelled, or isn't discoverable by pytest (e.g., in a `conftest.py` that's out of scope).
  fix Check the spelling of the fixture name, ensure the fixture is defined within a `conftest.py` in an appropriate directory, or explicitly imported if it's not a root-level plugin fixture. If using `pytest_plugins = ['pytest_fixture_config']`, verify it's correctly specified.

• AttributeError: 'MyAppConfig' object has no attribute 'new_attribute'

  cause You are attempting to access an attribute on a `Config` subclass instance that was not declared in its `__slots__` attribute.
  fix Add the 'new_attribute' to the `__slots__` tuple in your `MyAppConfig` class definition. Remember that classes using `__slots__` do not support dynamic attribute assignment outside of the defined slots.

Warnings

• breaking Python 2 and Python <3.6 support has been dropped. All compatibility code for older Python versions was removed in v1.8.0.
  Fix: Upgrade your Python environment to version 3.6 or newer.
• breaking The `mock` package is no longer used. All mock-related functionality now uses the standard library's `unittest.mock` module.
  Fix: Update any code directly importing or relying on the standalone `mock` package to use `unittest.mock` instead.
• breaking Usage of `path.py` and `path` has been removed in favor of `pathlib` for file system path operations.
  Fix: Refactor any code interacting with `pytest-fixture-config` that might have implicitly relied on `path.py` objects, migrating to `pathlib.Path` objects.
• gotcha Ensure your `pytest-fixture-config` plugin is discoverable by pytest. It must be installed in the environment where pytest runs, or explicitly enabled if not using setuptools entry points.
  Fix: Verify `pip install pytest-fixture-config` completed successfully. If using a `conftest.py`, ensure `pytest_plugins = ['pytest_fixture_config']` is present if auto-discovery fails.

Install

• pip install pytest-fixture-config Install stable version

Imports

• Config

  from pytest_fixture_config import Config

• requires_config

  from pytest_fixture_config import requires_config

• yield_requires_config

  from pytest_fixture_config import yield_requires_config

Quickstart

This quickstart demonstrates how to define a configuration class using `pytest_fixture_config.Config`, populate it from environment variables, and use the `requires_config` decorator to create fixtures that conditionally skip tests if necessary configuration values are not provided. This ensures tests requiring specific setups only run when their prerequisites are met.

import os
import pytest
import subprocess
from pytest_fixture_config import Config, requires_config

# 1. Define your configuration class inheriting from Config
class MyAppConfig(Config):
    __slots__ = ('api_key', 'base_url') # Define expected config attributes

# 2. Create a singleton instance, reading from environment variables
APP_CONFIG = MyAppConfig(
    api_key=os.environ.get('MY_APP_API_KEY'), # No default, required
    base_url=os.environ.get('MY_APP_BASE_URL', 'https://api.example.com') # With default
)

# 3. Use requires_config decorator to make fixtures dependent on config
@pytest.fixture
@requires_config(APP_CONFIG, ['api_key'])
def authenticated_client():
    """Provides an authenticated client if API_KEY is set."""
    print(f"\nUsing API Key: {APP_CONFIG.api_key[:5]}... and Base URL: {APP_CONFIG.base_url}")
    # In a real app, this would initialize an API client
    class MockClient:
        def fetch_data(self): return {"status": "data_fetched"}
    return MockClient()

def test_data_fetch(authenticated_client):
    """This test requires a valid API_KEY to run."""
    assert authenticated_client.fetch_data() == {"status": "data_fetched"}

# To run this example:
# 1. Save as `test_app.py`
# 2. Run: `pytest -s test_app.py` (it will be skipped)
# 3. Set env var: `export MY_APP_API_KEY="your_secret_key"`
# 4. Run again: `pytest -s test_app.py` (it should pass)