add integration test

tests/integration/test_extra_overlay_function.py

@@ -0,0 +1,88 @@
+"""Test case for displaying the connection banner when the websocket drops."""
+
+from typing import Generator
+
+import pytest
+from selenium.webdriver.common.by import By
+
+from reflex.testing import AppHarness, WebDriver
+
+
+def ExtraOverlay():
+    import reflex as rx
+
+    # Simulate reflex cloud deploy
+    rx.config.get_config().extra_overlay_function = "reflex.components.moment.moment"
+
+    def index():
+        return rx.vstack(
+            rx.el.input(
+                id="token",
+                value=rx.State.router.session.client_token,
+                is_read_only=True,
+            ),
+            rx.text(
+                "Hello World",
+            ),
+        )
+
+    app = rx.App(_state=rx.State)
+    app.add_page(index)
+
+
+@pytest.fixture(scope="module")
+def extra_overlay(tmp_path_factory) -> Generator[AppHarness, None, None]:
+    """Start ExtraOverlay app at tmp_path via AppHarness.
+
+    Args:
+        tmp_path_factory: pytest tmp_path_factory fixture
+
+    Yields:
+        running AppHarness instance
+    """
+    with AppHarness.create(
+        root=tmp_path_factory.mktemp("extra_overlay"),
+        app_source=ExtraOverlay,
+    ) as harness:
+        assert harness.app_instance is not None, "app is not running"
+        yield harness
+
+
+@pytest.fixture
+def driver(extra_overlay: AppHarness):
+    """Get an instance of the browser open to the extra overlay app.
+
+    Args:
+        extra_overlay: harness for the ExtraOverlay app.
+
+    Yields:
+        WebDriver instance.
+    """
+    driver = extra_overlay.frontend()
+    try:
+        token_input = driver.find_element(By.ID, "token")
+        assert token_input
+        # wait for the backend connection to send the token
+        token = extra_overlay.poll_for_value(token_input)
+        assert token is not None
+
+        yield driver
+    finally:
+        driver.quit()
+
+
+def test_extra_overlay(driver: WebDriver, extra_overlay: AppHarness):
+    """Test the ExtraOverlay app.
+
+    Args:
+        driver: WebDriver instance.
+        extra_overlay: harness for the ExtraOverlay app.
+    """
+    # Check that the text is displayed.
+    text = driver.find_element(By.XPATH, "//*[contains(text(), 'Hello World')]")
+    assert text
+    assert text.text == "Hello World"
+
+    time = driver.find_element(By.TAG_NAME, "time")
+    assert time
+    assert time.text