Function test_mixed_cond_event_lambda

tests/integration/test_event_chain.py:750–778

Verify a lambda returning rx.cond with a FunctionVar branch and an EventSpec branch. Each branch is exercised end-to-end: the FunctionVar branch updates a DOM data-attribute via a frontend-only function, and the EventSpec branch dispatches a backend event handler. Args: eve

(event_chain: AppHarness, driver: WebDriver)

def test_mixed_cond_event_lambda(event_chain: AppHarness, driver: WebDriver):
    """Verify a lambda returning rx.cond with a FunctionVar branch and an EventSpec branch.

    Each branch is exercised end-to-end: the FunctionVar branch updates a DOM
    data-attribute via a frontend-only function, and the EventSpec branch
    dispatches a backend event handler.

    Args:
        event_chain: AppHarness for the event_chain app
        driver: selenium WebDriver open to the app
    """
    assert_token(event_chain, driver)
    cond_input = driver.find_element(By.ID, "cond_input")
    marker = driver.find_element(By.ID, "mixed_cond_marker")
    btn = driver.find_element(By.ID, "mixed_cond_btn")

    # Default cond_input ("") -> EventSpec branch fires the backend handler.
    btn.click()
    poll_assert_event_order(driver, ["event_arg:ev_branch"])
    assert marker.get_attribute("data-value") == ""

    # Switch to the FunctionVar branch and click again.
    cond_input.send_keys("fn")
    assert event_chain.poll_for_content(marker, exp_not_equal="") == "fn"
    btn.click()
    AppHarness._poll_for(lambda: marker.get_attribute("data-value") == "fn_branch")
    assert marker.get_attribute("data-value") == "fn_branch"
    # Backend event order is unchanged because only the frontend function ran.
    poll_assert_event_order(driver, ["event_arg:ev_branch"])