add e2e test

test/e2e/fixtures/DataGrid/ConcurrentReactUpdate.tsx

@@ -0,0 +1,15 @@
+import * as React from 'react';
+import { XGrid } from '@material-ui/x-grid';
+
+export function DeferRenderingSnap() {
+  const [deferRows, setRows] = React.useState<any>([]);
+  const [deferColumns] = React.useState([{ field: 'id', headerName: 'Id', width: 100 }]);
+
+  React.useEffect(() => {
+    setTimeout(() => setRows(() => []), 0);
+    setTimeout(() => setRows(() => []), 0);
+    setTimeout(() => setRows(() => [{ id: '1' }, { id: '2' }]), 1);
+  }, []);
+
+  return <XGrid autoHeight columns={deferColumns} rows={deferRows} />;
+}

test/e2e/index.test.ts

@@ -1,5 +1,6 @@
 import { expect } from 'chai';
 import * as playwright from 'playwright';
+import { raf } from 'test/utils/helperFn';
 
 function sleep(timeoutMS: number): Promise<void> {
   return new Promise((resolve) => {
@@ -105,5 +106,15 @@ describe('e2e', () => {
         await page.evaluate(() => document.activeElement?.getAttribute('data-testid')),
       ).to.equal('initial-focus');
     });
+
+    it('should display the rows', async () => {
+      await renderFixture('DataGrid/ConcurrentReactUpdate');
+      await sleep(100);
+      expect(
+        await page.evaluate(() =>
+          Array.from(document.querySelectorAll('[role="cell"]')).map((node) => node.textContent),
+        ),
+      ).to.deep.equal(['1', '2']);
+    });
   });
 });