tests: Add test for comment mention

Author: hemangsk

tests/e2e_tests/incidents_alerts_tests/test_mentions_in_incident_comments.py

@@ -0,0 +1,51 @@
+from playwright.sync_api import Page, expect
+from tests.e2e_tests.test_end_to_end import init_e2e_test, setup_console_listener
+from tests.e2e_tests.utils import save_failure_artifacts
+
+
+KEEP_UI_URL = "http://localhost:3000"
+
+def test_mentions_in_incident_comments(browser: Page, setup_page_logging, failure_artifacts):
+    test_id = "test_mentions_in_comments"
+    log_entries = []
+    setup_console_listener(browser, log_entries)
+    
+    # Initialize test and go to incidents page
+    init_e2e_test(browser, next_url="/incidents")
+    browser.wait_for_selector("[data-testid='incidents-table']")
+    
+    try:
+        browser.get_by_role("button", name="Create Incident").click()
+        
+        incident_title = f"Test Incident {test_id}"
+        browser.get_by_test_id("base-input").click()
+        browser.get_by_test_id("base-input").fill(incident_title)
+        
+        summary_div = browser.locator("div").filter(has_text=re.compile(r"^Summary$"))
+        summary_div.get_by_role("paragraph").nth(1).click()
+        summary_div.locator("div").nth(3).fill("Test Incident Summary for mentions test")
+        
+        browser.get_by_role("button", name="Who is responsible").click()
+        browser.get_by_role("option", name="keep").click()
+        
+        # Create a new incident
+        browser.get_by_role("button", name="Create").click()
+        
+        browser.get_by_role("link", name=incident_title, exact=True).click()
+        
+        browser.get_by_role("tab", name="Activity").click()
+        
+        browser.get_by_test_id("base-input").click()
+        browser.get_by_test_id("base-input").fill("Test comment @keep")
+        
+        browser.wait_for_selector("text=keep", timeout=5000)
+        browser.get_by_text("keep").nth(2).click()
+        
+        browser.get_by_role("button", name="Comment").click()
+        
+        # Verify the mention is visible
+        expect(browser.get_by_text("@keep")).to_be_visible()
+        
+    except Exception as e:
+        save_failure_artifacts(browser, log_entries=log_entries)
+        raise e