gui_e2e: create helper functions to check warnings

and use them instead of plain code.

follow-up from CMK-34806

Change-Id: Idb496e134b50ceb0d41160ff9a6ec4ac051b6c2f

Author: asyash26

tests/system/gui/test_hosts.py

@@ -48,7 +48,7 @@ def test_navigate_to_host_properties(host: HostProperties) -> None:
 
     # - check absence of errors and warnings
     expect(host.main_area.locator("div.error")).to_have_count(0)
-    expect(host.main_area.locator("div.warning")).to_have_count(0)
+    host.main_area.check_no_warnings()
 
 
 def test_create_and_delete_a_host(dashboard_page: MainDashboard, test_site: Site) -> None:

tests/system/gui/testlib/playwright/pom/page.py

@@ -570,6 +570,33 @@ def expect_no_entries(self) -> None:
         """
         expect(self.get_text("No entries.")).to_be_visible()
 
+    @property
+    def warning(self) -> Locator:
+        """The warning banner shown in the main area, if any."""
+        return self.locator("div.warning")
+
+    def check_warning_shown(self) -> None:
+        """Assert that exactly one warning banner is shown."""
+        expect(self.warning, message="No (single) warning banner is shown").to_have_count(1)
+
+    def check_warning_texts(self, *expected_texts: str) -> None:
+        """Assert that exactly one warning banner is shown, containing all given texts.
+
+        Pass each expected text as a separate positional argument, e.g.
+        `self.check_warning_texts("hello", "world", "universe", "galaxy")` asserts that a
+        single warning banner is shown and contains all four texts.
+        """
+        assert expected_texts, "check_warning_texts() requires at least one expected text"
+        self.check_warning_shown()
+        for text in expected_texts:
+            expect(
+                self.warning, message=f"Warning banner does not contain text: '{text}'"
+            ).to_contain_text(text)
+
+    def check_no_warnings(self) -> None:
+        """Assert that no warning banner is shown."""
+        expect(self.warning, message="A warning banner is shown unexpectedly").to_have_count(0)
+
     def locator_via_xpath(self, element: str, text: str) -> Locator:
         """Return a locator defined by element and text via xpath."""
         return self.locator(f"//{element}[text() = '{text}']")