[Refactor] Use NodeSlot.hasErrors API (#3284)

Co-authored-by: github-actions <github-actions@github.com>

browser_tests/tests/execution.spec.ts

@@ -0,0 +1,20 @@
+import { expect } from '@playwright/test'
+
+import { comfyPageFixture as test } from '../fixtures/ComfyPage'
+
+test.describe('Execution', () => {
+  test('Report error on unconnected slot', async ({ comfyPage }) => {
+    await comfyPage.disconnectEdge()
+    await comfyPage.clickEmptySpace()
+
+    await comfyPage.executeCommand('Comfy.QueuePrompt')
+    await expect(comfyPage.page.locator('.comfy-error-report')).toBeVisible()
+    await comfyPage.page.locator('.p-dialog-close-button').click()
+    await comfyPage.page.locator('.comfy-error-report').waitFor({
+      state: 'hidden'
+    })
+    await expect(comfyPage.canvas).toHaveScreenshot(
+      'execution-error-unconnected-slot.png'
+    )
+  })
+})