magento2/magento2-page-builder#636: Responsive breakpoint switcher

- fix static test

Author: omiroshnichenko

app/code/Magento/PageBuilder/view/adminhtml/web/js/master-format/read/configurable.js

@@ -45,6 +45,8 @@ export default class Configurable implements ReadInterface {
                 const [propertyReaderPool, converterPool, massConverterPool] = loadedComponents;
                 const viewports = Config.getConfig("viewports");
                 const data: {[key: string]: any} = {};
+
+                _.each(viewports, (viewport, name) => data[name] = {});
                 for (const elementName of Object.keys(config.elements)) {
                     const elementConfig = config.elements[elementName];
                     const currentElement = this.findElementByName(element, elementName);

app/code/Magento/PageBuilder/view/adminhtml/web/js/master-format/render/frame.js

@@ -48,6 +48,8 @@ export default function listen(config: ConfigInterface) {
 
     Config.setConfig(config);
     Config.setMode("Master");
+    // Override assign with extend to prevent deep object overriding.
+    Object.assign = mageUtils.extend;
 
     /**
      * Create a listener within our iframe so we can observe messages from the parent, once we receive a port on the