feat: support React 18 (#101)

Author: adamstankiewicz

Diff for: example-plugin-app/package-lock.json

@@ -4,19 +4,18 @@
   "description": "",
   "main": "index.jsx",
   "scripts": {
-    "lint": "fedx-scripts eslint --ext .js --ext .jsx . --resolve-plugins-relative-to .",
-    "lint:fix": "fedx-scripts eslint --fix --ext .js --ext .jsx . --resolve-plugins-relative-to .",
+    "lint": "fedx-scripts eslint --ext .js --ext .jsx --ext .ts --ext .tsx . --resolve-plugins-relative-to .",
+    "lint:fix": "npm run lint -- --fix",
     "start": "fedx-scripts webpack-dev-server --progress"
   },
   "keywords": [],
   "author": "edX",
   "license": "AAGPL-3.0",
   "dependencies": {
-    "@openedx/frontend-build": "^14.0.3",
+    "@openedx/frontend-build": "^14.3.1",
     "core-js": "^3.29.1",
-    "react": "^17.0.0",
-    "react-dom": "^17.0.0",
-    "react-router-dom": "^6.22.1",
-    "regenerator-runtime": "^0.14.1"
+    "react": "^18.0.0",
+    "react-dom": "^18.0.0",
+    "react-router-dom": "^6.22.1"
   }
 }

Diff for: example-plugin-app/package.json

@@ -1,8 +1,7 @@
 import 'core-js/stable';
-import 'regenerator-runtime/runtime';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { StrictMode } from 'react';
+import { createRoot } from 'react-dom/client';
 import { Routes, Route } from 'react-router-dom';
 
 import { AppProvider, ErrorPage, PageWrap } from '@edx/frontend-platform/react';
@@ -15,20 +14,28 @@ import PluginIframe from './PluginIframe';
 
 import './index.scss';
 
+const container = document.getElementById('root');
+const root = createRoot(container);
+
 subscribe(APP_READY, () => {
-  ReactDOM.render(
-    <AppProvider>
-      <Routes>
-        <Route path="/default_iframe" element={<PageWrap><DefaultIframe /></PageWrap>} />
-        <Route path="/plugin_iframe" element={<PageWrap><PluginIframe /></PageWrap>} />
-      </Routes>
-    </AppProvider>,
-    document.getElementById('root'),
+  root.render(
+    <StrictMode>
+      <AppProvider>
+        <Routes>
+          <Route path="/default_iframe" element={<PageWrap><DefaultIframe /></PageWrap>} />
+          <Route path="/plugin_iframe" element={<PageWrap><PluginIframe /></PageWrap>} />
+        </Routes>
+      </AppProvider>
+    </StrictMode>
   );
 });
 
 subscribe(APP_INIT_ERROR, (error) => {
-  ReactDOM.render(<ErrorPage message={error.message} />, document.getElementById('root'));
+  root.render(
+    <StrictMode>
+      <ErrorPage message={error.message} />
+    </StrictMode>,
+  );
 });
 
 initialize({