Initial commit of 001code-html Scratch frontend project.

Includes scratch-gui, scratch-vm, scratch-blocks, scratch-render, scratch-l10n, and deployment config.

Co-authored-by: Cursor <cursoragent@cursor.com>

scratch-gui/test/unit/components/error-boundary-hoc.test.jsx

@@ -0,0 +1,43 @@
+import React from 'react';
+import {Provider} from 'react-redux';
+const {mountWithIntl} = require('../../helpers/intl-helpers.jsx');
+
+import configureStore from 'redux-mock-store';
+
+import CrashMessageComponent from '../../../src/components/crash-message/crash-message.jsx';
+import ErrorBoundary from '../../../src/containers/error-boundary.jsx';
+
+const ChildComponent = () => <div>hello</div>;
+
+describe('ErrorBoundary', () => {
+    const mockStore = configureStore();
+    let store;
+
+    beforeEach(() => {
+        store = mockStore({
+            locales: {
+                isRtl: false,
+                locale: 'en-US'
+            }
+        });
+    });
+
+    test('ErrorBoundary shows children before error and CrashMessageComponent after', () => {
+        const child = <ChildComponent />;
+        const wrapper = mountWithIntl(
+            <Provider store={store}><ErrorBoundary action="test">{child}</ErrorBoundary></Provider>
+        );
+        const errorSite = wrapper.childAt(0).childAt(0);
+
+        // @ts-ignore: 'onReload' prop is absent because this component will only be used for pattern matching
+        const crashMessagePattern = <CrashMessageComponent />;
+
+        expect(wrapper.containsMatchingElement(child)).toBeTruthy();
+        expect(wrapper.containsMatchingElement(crashMessagePattern)).toBeFalsy();
+
+        errorSite.simulateError(new Error('fake error for testing purposes'));
+
+        expect(wrapper.containsMatchingElement(child)).toBeFalsy();
+        expect(wrapper.containsMatchingElement(crashMessagePattern)).toBeTruthy();
+    });
+});