Shallow object comparison is not a special property of Immutable.js. It's just a matter of iterating over the keys and values of two objects and comparing them

Shallow object comparison is not a special property of Immutable.js. It's just a matter of iterating over the keys and values of two objects and comparing them. In fact, that's how React-Redux (and many other React ecosystem libs) work. `connect` decides whether to re-render your component by doing shallow comparisons of the previous and current `mapState` return object to see if the extracted values have changed. All that's necessary is to do immutable updates of your data, by always making _copies_ of the data and modifying the copies (see [0] and [1] for discussions of immutable updates). It doesn't matter whether the new object references were produced by manually creating copies ( `{...obj}`, `someArray.map()`, etc), by using Immutable.js's API, or Immer tracking the "mutations" via a proxy and creating the new references internally. As long as you have immutable updates and new references, shallow comparisons work fine. So, there's nothing special you need to do to make Immer work with comparisons. You literally just use it as described in the docs. Specifically for comparisons, `PureComponent` and `React.memo()` both do shallow comparisons of `props` by default. Yes, the pervasiveness of Immutable.js's API is one of the reasons I've long suggested that folks avoid it [2]. I don't have any detailed suggestions for migrating, other than perhaps consistently using Reselect selectors to encapsulate reading values from the store and handling the Immutable.js -> `toJS()` conversion (which you should probably be doing anyway as a perf optimization, since that conversion is relatively "expensive"). That way, as you switch over chunks of reducer logic from Immutable.js to Immer, the code consuming those values _should_ still be getting POJOs out of the selectors, with no actual visible change. [0] https://redux.js.org/recipes/structuring-reducers/immutable-update-patterns https://redux.js.org/recipes/structuring-reducers/immutable-... [1] https://daveceddia.com/react-redux-immutability-guide/ https://daveceddia.com/react-redux-immutability-guide/ [2] https://www.reddit.com/r/javascript/comments/4rcqpx/dan_abramov_redux_is_not_an_architecture_or/d51g4k4?context=3 https://www.reddit.com/r/javascript/comments/4rcqpx/dan_abra...