feat: improve provider testing (#1280)

tests/debug-page-broadcast.spec.ts

@@ -0,0 +1,22 @@
+import { expect } from '@playwright/test';
+
+import { test } from './libs/playwright';
+
+test.describe('Debug page broadcast', () => {
+  test('should broadcast a message to all debug pages', async ({
+    page,
+    context,
+  }) => {
+    await page.goto('http://localhost:8080/_debug/broadcast');
+    const page2 = await context.newPage();
+    await page2.goto('http://localhost:8080/_debug/broadcast');
+    await page.waitForSelector('#__next');
+    await page2.waitForSelector('#__next');
+    await page.click('[data-testid="create-page"]');
+    expect(await page.locator('tr').count()).toBe(2);
+    expect(await page2.locator('tr').count()).toBe(2);
+    await page2.click('[data-testid="create-page"]');
+    expect(await page.locator('tr').count()).toBe(3);
+    expect(await page2.locator('tr').count()).toBe(3);
+  });
+});