feat: Add testcontainers and Playwright (no-changelog) (#16662)

Co-authored-by: Tomi Turtiainen <10324676+tomi@users.noreply.github.com>

packages/testing/playwright/composables/WorkflowComposer.ts

@@ -0,0 +1,25 @@
+import type { n8nPage } from '../pages/n8nPage';
+
+/**
+ * A class for user interactions with workflows that go across multiple pages.
+ */
+export class WorkflowComposer {
+	constructor(private readonly n8n: n8nPage) {}
+
+	/**
+	 * Executes a successful workflow and waits for the notification to be closed.
+	 * This waits for http calls and also closes the notification.
+	 */
+	async executeWorkflowAndWaitForNotification(notificationMessage: string) {
+		const responsePromise = this.n8n.page.waitForResponse(
+			(response) =>
+				response.url().includes('/rest/workflows/') &&
+				response.url().includes('/run') &&
+				response.request().method() === 'POST',
+		);
+
+		await this.n8n.canvas.clickExecuteWorkflowButton();
+		await responsePromise;
+		await this.n8n.notifications.waitForNotificationAndClose(notificationMessage);
+	}
+}