fix: Menu defaultOpenKeys not work in React18 (#502)

* fix: Menu defaultOpenKeys not work in React18

* fix: mount check logic

src/Menu.tsx

@@ -293,7 +293,6 @@ const Menu = React.forwardRef<MenuRef, MenuProps>((props, ref) => {
   // Restore
   React.useEffect(() => {
     if (!mountRef.current) {
-      mountRef.current = true;
       return;
     }
 
@@ -305,6 +304,14 @@ const Menu = React.forwardRef<MenuRef, MenuProps>((props, ref) => {
     }
   }, [isInlineMode]);
 
+  React.useEffect(() => {
+    mountRef.current = true;
+
+    return () => {
+      mountRef.current = false;
+    };
+  }, []);
+
   // ========================= Path =========================
   const {
     registerPath,

tests/React18.spec.tsx

@@ -0,0 +1,59 @@
+/* eslint-disable no-undef */
+import React from 'react';
+import { act, render } from '@testing-library/react';
+import Menu, { MenuItem, SubMenu } from '../src';
+import type { MenuProps } from '../src';
+
+describe('React18', () => {
+  function runAllTimer() {
+    for (let i = 0; i < 10; i += 1) {
+      act(() => {
+        jest.runAllTimers();
+      });
+    }
+  }
+
+  beforeEach(() => {
+    jest.useFakeTimers();
+  });
+
+  afterEach(() => {
+    jest.useRealTimers();
+  });
+
+  function createMenu(props?: MenuProps) {
+    return (
+      <React.StrictMode>
+        <Menu {...props}>
+          <SubMenu key="s1" title="submenu1">
+            <MenuItem key="s1-1">1</MenuItem>
+            <SubMenu key="s1-2" title="submenu1-1">
+              <MenuItem key="s1-2-1">2</MenuItem>
+            </SubMenu>
+          </SubMenu>
+          <SubMenu key="s2" title="submenu2">
+            <MenuItem key="s2-2">2</MenuItem>
+          </SubMenu>
+        </Menu>
+      </React.StrictMode>
+    );
+  }
+
+  it("don't show submenu when disabled", () => {
+    const { container } = render(
+      createMenu({
+        defaultOpenKeys: ['s1'],
+        mode: 'horizontal',
+      }),
+    );
+
+    runAllTimer();
+
+    expect(
+      container
+        .querySelector('.rc-menu-submenu-open')
+        .querySelector('.rc-menu-submenu-title').textContent,
+    ).toEqual('submenu1');
+  });
+});
+/* eslint-enable */