[fix][compile] Ensure root component is always present

Author: Nora Tarano

scripts/buildCSS.js

@@ -20,6 +20,12 @@ registerCSSInterfaceWithDefaultTheme();
 const path = './scripts/renderAllComponents.jsx';
 const CSS = compileCSS(path);
 
+if (CSS === '') {
+  throw new Error('Failed to compile CSS');
+} else {
+  console.log('CSS compilation complete.');
+}
+
 const format = new CleanCSS({
   level: optimizeForProduction ? 2 : 0,
   format: 'beautify',

scripts/renderAllComponents.jsx

@@ -5,6 +5,13 @@ import DateRangePickerWrapper from '../examples/DateRangePickerWrapper';
 import SingleDatePickerWrapper from '../examples/SingleDatePickerWrapper';
 import PresetDateRangePickerWrapper from '../examples/PresetDateRangePicker';
 
+if (!document.getElementById('root')) {
+  // Make sure the #root element is defined
+  const root = document.createElement('div');
+  root.id = 'root';
+  document.body.appendChild(root);
+}
+
 function App() {
   return (
     <div>