Adds additional safeguards for edge cases, and improves theme coverage

src/utils/ErrorHandler.js

@@ -0,0 +1,11 @@
+/* eslint no-console: ["error", { allow: ["warn", "error"] }] */
+
+/**
+ * Function called when an error happens
+ * If you wish to use an error logging service, put code for it here
+ */
+const ErrorHandler = function handler(msg) {
+  console.warn(msg);
+};
+
+export default ErrorHandler;