immutable-js VS immutability-helper

immutable for JavaScript.

Check out Object.freeze. There's also Immutable.js for working with immutable data.

Use immutability to manage state updates When updating state in your React application, it's important to ensure that you are not mutating the original state object. Instead, you should create a new copy of the state object with the updated values. Immutability makes it easier to manage state updates and ensures that the updates are performed in a predictable and safe manner. Libraries like Immutable.js provide a set of functions that simplify working with immutable data in React applications.

Enter Immutable.js, a library for creating and updating immutable state in JavaScript. With usual mutable JavaScript objects you might write something like:

The Immutable.js README has a much more complete description of immutability and why you might want to use the library. Also worth mentioning that Immer is an alternative which is a bit easier to get started with.

Examples: immutable-js Immer

I can't speak to C# and Java, but the suggestion in this post: ImmutableJS already uses Persistent data structures. (It's the second sentence of their introduction)

feed.feedManager.state.activities is an immutable Map (created with Immutabe.js), so you get the activity object using getIn and toJS methods.

You could create explicitly immutable references and state by using a tool like Immer.js or Immutable.js and do something like your example using their API.

if you're feeling fancy, try out https://www.npmjs.com/package/immutability-helper

I doubt that’s true, check this out, it’s designed with your use case in mind.

This tutorial uses the create-react-app as the starting template. The react and react-dom dependencies are both version 17.0.2. The react-scripts is version 4.0.0. The yup library is the fourth dependency and it is version 0.32.9. The fifth and last dependency is immutability-helper, version 3.1.1.

Are you perplexed by the syntax of immutability-helper? Repulsed by immer.js's use of assignment? Alarmed by lodash's lack of type safety?

Take a look at https://github.com/kolodny/immutability-helper for deeply-nested updates.