use-immer VS Immer

The use-immer package additionally provides a useImmerReducer ****function that allows you to make state transitions via direct mutation, but under the hood creates an immutable copy using Proxies in JavaScript.

Apply useImmer to the top component state and the dream is complete.

If you want to use mutating code while ensuring that the final update is immutable, I recommend checking out useImmer (and useImmerReducer) - it uses immer to track mutations and do them immutably for you.

If you find yourself using multiple objects or in your state, it may be worth it to install a library like immer. Immer provides a proxy object, referred to as a draft, so while your code appears similar to a direct mutation of state, a copy is created under the hood when an update when immer is used.

useImmer is also pretty nice too - useReducer is definitely the way if you only want specific ways to manipulate the object though (and useImmerReducer can make writing the logic for that easier too)

Within the component itself, I used a useImmer hook for the state, as it lets me write mutating code while ensuring that the actual update is immutable - but if you're only holding your array in the useState hook, a shallow clone would work fine. js setItems(items => arrayMove([...items], ...params))

React is a lot more strict, and for what we need we cannot leave the state in individual components, we need to pull it up to the App component. Making modifications to deeply nested state is a lot of nasty code, fortunately React world has a solution - immer and its hooks version useImmer.

Immer is a lightweight package that simplifies working with immutable states. Immutable data structures ensure efficient data change detection, making it easier to track modifications. Additionally, they enable cost-effective cloning by sharing unchanged parts of a data tree in memory.

```

It looks like it’s mutating, but both the reducers and update() uses immer* under the hood, so we still respect immutability under the hood.

Cami supports redux devtools so you can use that for time-travel debugging too!

—-

* https://github.com/immerjs/immer

I heard that immutability libraries like immer.js [0] help with this. Anyone go this way and had good success? Is this 'the way'?

[0]: https://immerjs.github.io/immer/

So, that's what we built, and we built it in the most obvious way — using JavaScript Proxy objects to track mutations and reflect those changes across Appsmith’s framework. Initially things looked good — it worked, aside from a few hacks to make some data types work with map and set, and we were following the example of other projects that had similar requirements. If it was good enough for them, it should be good enough for us, right?

But is immer really the ultimate answer? The performance problem of immer is more prominent in large arrays and deep-level object scenarios. See this issue description, many authors in the community began to try to make breakthroughs, and noticed that structura and mutative, I found that it is indeed many times faster than immer as they said, but it still fails to solve the problem of both fast speed and good development experience. I will analyze the two issues in detail below.

I like immer for this kind of thing: https://github.com/immerjs/immer

It gives you immutable updates without getting bogged down in FP abstractions.

I've always been a huge fan of immer for these case. For your code, it would simply turn into setGridData((prev) => produce(prev, draft => applyChanges(changes, draft)) but I recommend you go over their documentation to fully understand how it works

If you're trying to make things actually immutable, Object.freeze and deep copies can clutter things up pretty good, have you considered using something like immer? (https://immerjs.github.io/immer/)