Test: add editor test coverage (#3598)

cypress/plugins/testBackend.js

@@ -0,0 +1,14 @@
+const { updateConfig } = require('../utils/config');
+const { merge } = require('lodash');
+
+async function setupTestBackend(options) {
+  await updateConfig(current => {
+    merge(current, options);
+  });
+
+  return null;
+}
+
+module.exports = {
+  setupTestBackend,
+};