refactor(citrus-simulator-ui): refactor error-banner test

simulator-ui/tests/error-banner.spec.ts

@@ -1,14 +1,25 @@
 import { expect, Page, test } from '@playwright/test';
-import { goToAllNavigationTabsAndOptionallyValidateContent, mockErrorResponseForAllNavbarLinkedSites } from './helpers/helper-functions';
+import {
+  goToAllNavigationTabsAndOptionallyValidateContent,
+  mockResponseForAllNavbarLinkedSites
+} from './helpers/helper-functions';
 
 test.beforeEach(async ({ page }) => {
   await page.goto('http://localhost:9000/');
 });
 
 test('should show error banner if there is an error code in the backend response while loading any page', async ({ page }) => {
-  await mockErrorResponseForAllNavbarLinkedSites(page);
+  await mockResponseForAllNavbarLinkedSites(page, mock500ErrorResponseForApiURL);
 
   await goToAllNavigationTabsAndOptionallyValidateContent(page, verifyErrorBannerIsVisible);
 });
 
 const verifyErrorBannerIsVisible = async (pageToPass: Page): Promise<void> => await expect(pageToPass.getByTestId('error')).toBeVisible();
+
+const mock500ErrorResponseForApiURL = async (page: Page, apiLink: string): Promise<void> => {
+  await page.route(apiLink, async route => {
+    await route.fulfill({
+      status: 500,
+    });
+  });
+};