add a test to catch the error

tests/integration/tests_playwright/test_link_hover.py

@@ -0,0 +1,45 @@
+from typing import Generator
+
+import pytest
+from playwright.sync_api import Page, expect
+
+from reflex.testing import AppHarness
+
+
+def LinkApp():
+    import reflex as rx
+
+    app = rx.App()
+
+    def index():
+        return rx.vstack(
+            rx.link(
+                "Click me",
+                href="#",
+                color="blue",
+                _hover=rx.Style({"color": "red"}),
+            )
+        )
+
+    app.add_page(index, "/")
+
+
+@pytest.fixture
+def link_app(tmp_path_factory) -> Generator[AppHarness, None, None]:
+    with AppHarness.create(
+        root=tmp_path_factory.mktemp("appearance_app"),
+        app_source=LinkApp,  # type: ignore
+    ) as harness:
+        assert harness.app_instance is not None, "app is not running"
+        yield harness
+
+
+def test_link(link_app: AppHarness, page: Page):
+    assert link_app.frontend_url is not None
+    page.goto(link_app.frontend_url)
+
+    link = page.get_by_role("link")
+    expect(link).to_have_text("Click me")
+    expect(link).to_have_css("color", "rgb(0, 0, 255)")
+    link.hover()
+    expect(link).to_have_css("color", "rgb(255, 0, 0)")