def driver(computed_vars: AppHarness) -> Generator[WebDriver, None, None]:
    """Get an instance of the browser open to the computed_vars app.

    Args:
        computed_vars: harness for ComputedVars app

    Yields:
        WebDriver instance.
    """
    assert computed_vars.app_instance is not None, "app is not running"
    driver = computed_vars.frontend()
    try:
        yield driver
    finally:
        driver.quit()
Get an instance of the browser open to the computed_vars app.

    Args:
        computed_vars: harness for ComputedVars app

    Yields:
        WebDriver instance.
    
tests/integration/test_computed_vars.py