Redux store is not a singleton anymore (-> bug fixes)

app/javascript/helpers/createStore.ts

@@ -0,0 +1,15 @@
+import { createStore, applyMiddleware } from 'redux';
+import thunkMiddleware from 'redux-thunk';
+
+import rootReducer from '../reducers/rootReducer';
+
+const createStoreHelper = () => (
+  createStore(
+    rootReducer,
+    applyMiddleware(
+      thunkMiddleware,
+    ),
+  )
+);
+
+export default createStoreHelper;