Error after freezing store state

[larsbs]

Hello

I'm monkeypatching the store to freeze the result of store.getState() during development and I'm getting a weird error in only one connected component. The error is:

Uncaught TypeError: Cannot assign to read only property 'setWrappedInstance' of object '#<Connect>'

and it's happening on this line in connectAdvanced.js. What's the relation between getState() and connectAdvanced so that error is happening?

It's related for sure to freezing the state and also to connect the component, what I don't know if it's the main cause of it's an underlying problem that's being triggered by it. But if I remove one of both conditions (freezing the state or connecting the component) the problem goes away.

EDIT:

This is the monkeypatching code in case it provides more context:

if (process.env.NODE_ENV === 'development') {
  const oldGetState = store.getState();
  store.getState = () => deepFreeze(oldGetState());
}

[timdorr]

Are you perhaps putting the wrapped component into state somewhere? I believe that's what the deepFreeze will do if you have it in there somewhere. That will end up making the component's properties frozen. How are you actually connecting the component?

[markerikson]

@larsbs : There are several other options for detecting mutations to state in development, including existing middlewares that freeze the state. You might want to look into those. See the DevTools#Linting section of my Redux addons catalog.

[larsbs]

The component is nothing fancy, it's exactly like this:

import React from 'react';
import { connect } from 'react-redux';

const Overview = () => {
  return (
    <div>Overview</div>
  );
};

export default connect()(Overview);  // If I remove this line, the error goes away.

For now I just disabled the freezing of the state, at this moment, the question is more a curiosity than a real problem, because I have the impression that something is going here under the hood.

@timdorr The wrapped component is a route, but also others, and they're not triggering the error.

@markerikson thanks, I'm gonna have a look.

[gpoitch]

Noticing this same error show up after a recent react-redux upgrade and using redux-freeze