Upgrade webpack to 4.35.0 to fix dynamic import issue (#7257)

* Upgrade webpack to 4.35.0 to fix dynamic import issue

* Add a test maybe?

packages/react-error-overlay/package.json

@@ -64,7 +64,7 @@
     "settle-promise": "1.0.0",
     "source-map": "0.5.6",
     "terser-webpack-plugin": "1.2.3",
-    "webpack": "^4.29.6"
+    "webpack": "^4.35.0"
   },
   "jest": {
     "setupFiles": [

packages/react-scripts/fixtures/kitchensink/src/App.js

@@ -68,7 +68,7 @@ class App extends Component {
     // This works around an issue of a duplicate hash in the href
     // Ex: http://localhost:3001/#array-destructuring#array-destructuring
     // This seems like a jsdom bug as the URL in initDom.js appears to be correct
-    const feature = url.slice(url.lastIndexOf("#") + 1);
+    const feature = url.slice(url.lastIndexOf('#') + 1);
 
     switch (feature) {
       case 'array-destructuring':
@@ -241,6 +241,11 @@ class App extends Component {
           this.setFeature(f.default)
         );
         break;
+      case 'dynamic-import':
+        import('./features/webpack/DynamicImport').then(f =>
+          this.setFeature(f.default)
+        );
+        break;
       default:
         this.setState({ error: `Missing feature "${feature}"` });
     }

packages/react-scripts/fixtures/kitchensink/src/features/webpack/DynamicImport.js

@@ -0,0 +1,12 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import React from 'react';
+
+export default () => {
+  return <>Hello World!</>;
+};

packages/react-scripts/fixtures/kitchensink/src/features/webpack/DynamicImport.test.js

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import React from 'react';
+import ReactDOM from 'react-dom';
+
+describe('dynamic import', () => {
+  it('renders without crashing', async () => {
+    import('./DynamicImport').then(DynamicImport => {
+      const div = document.createElement('div');
+      ReactDOM.render(<DynamicImport />, div);
+      expect(div.textContent).toBe('Hello World!');
+    });
+  });
+});

packages/react-scripts/package.json

@@ -76,7 +76,7 @@
     "terser-webpack-plugin": "1.2.3",
     "ts-pnp": "1.1.2",
     "url-loader": "1.1.2",
-    "webpack": "4.29.6",
+    "webpack": "4.35.0",
     "webpack-dev-server": "3.2.1",
     "webpack-manifest-plugin": "2.0.4",
     "workbox-webpack-plugin": "4.2.0"