test(e2e): validate webhook target url

frontend/tests/e2e/project/webhooks.spec.ts

@@ -0,0 +1,16 @@
+import {test, expect} from '../../support/fixtures'
+import {ProjectFactory} from '../../factories/project'
+
+test.describe('Project webhooks', () => {
+	test.beforeEach(async ({authenticatedPage, currentUser}) => {
+		await ProjectFactory.create(1, {id: 1, owner_id: currentUser.id}, false)
+	})
+
+	test('validates the target URL', async ({authenticatedPage: page}) => {
+		await page.goto('/projects/1/settings/webhooks')
+		await page.waitForLoadState('networkidle')
+		await page.locator('#targetUrl').fill('not-a-url')
+		await page.locator('#targetUrl').blur()
+		await expect(page.locator('.help.is-danger')).toContainText(/valid URL/i)
+	})
+})