Redux middleware that logs an error to the console when an action does not mutate state

Usage no npm install needed!

<script type="module">
  import reduxUnhandledAction from '';


Redux Unhandled Action

Circle CI

A simple redux middleware that will log an error to the console if the state returned from a dispatch is equal to the state before the dispatch.


npm install redux-unhandled-action --save


Takes a single argument, an optional callback that will be called if an action is unhandled. The default callback will log an error to the console with the action type.


import { createStore, applyMiddleware } from "redux";
import reduxUnhandledAction from "redux-unhandled-action";
import reducer from "./reducer";
const callback = (action) => console.error(`${action} didn't lead to creation of a new state object`);
const store = createStore(reducer, applyMiddleware(reduxUnhandledAction(callback)));

Copyright (C) 2017 Social Tables, Inc. ( All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.