connect swallows errors in mapStateToProps (new bug in 8.0.0)

What version of React, ReactDOM/React Native, Redux, and React Redux are you using?

• React: 18.2
• ReactDOM/React Native: react-dom 18.2
• Redux: 4.2.0
• React Redux: 8.0.2

What is the current behavior?

https://codesandbox.io/s/gifted-architecture-wr4f86?file=/src/App.js

1. Have a code that can cause an error in mapStateToProps, e.g.

const mapStateToProps = (state) => {
  return {
    foo: state.foo.length, // when foo is undefined, causes an error
  };
};

1. Dispatch an action that changes the state so that it causes the error above

dispatch(updateFoo(undefined));

1. Rerender doesn’t happen, no errors emitted in console, componentDidCatch catches nothing. The error is swallowed.

What is the expected behavior?

This issue makes debugging code that’s using react-redux really hard. The expected behaviour is that the error is visible in console. It worked fine in 7.2.8: https://codesandbox.io/s/charming-firefly-coekps

Which browser and OS are affected by this issue?

Windows, latest Chrome here. Probably affects all browsers.

Did this work in previous versions of React Redux?

• Yes

[markerikson]

@rdonnelly : afraid I don’t have the brain bandwidth to answer this one further atm. The logic in connect is frankly very fragile, doubly so in v8, and we’re not going to make further changes to it. I’d suggest trying out useSelector and see what happens.

[rdonnelly]

I think we’re running into something similar in our application. When we hit an error in a selector, the exception seems to get gobbled up here:

https://github.com/reduxjs/react-redux/blob/8cf538c05b21433eba2106a6609c6ccbfce471de/src/components/connect.tsx#L131-L141

We were previously relying on that thrown error to bubble up and get caught by an error handler, but now our app won’t re-render and won’t show an error. I won’t claim that this is the best pattern (the application code is pretty old at this point), but is there any way to let that error pass through? Or if we did switch to useSelector syntax rather than connect, would that alleviate our issues?