@reduxjs/toolkit

What is @reduxjs/toolkit?

The @reduxjs/toolkit package is a toolset for efficient Redux development. It is intended to be the standard way to write Redux logic, providing utilities to simplify common tasks such as store setup, creating reducers and actions, and writing immutable update logic.

What are @reduxjs/toolkit's main functionalities?

Creating a Redux Store

This feature simplifies the setup of the Redux store with sensible defaults and middleware like Redux Thunk.

import { configureStore } from '@reduxjs/toolkit';

const store = configureStore({ reducer: rootReducer });

Creating Slices

Slices are a way to define reducers and associated actions together in a single, concise object.

import { createSlice } from '@reduxjs/toolkit';

const counterSlice = createSlice({
  name: 'counter',
  initialState: 0,
  reducers: {
    increment: state => state + 1,
    decrement: state => state - 1
  }
});

export const { increment, decrement } = counterSlice.actions;

Creating Async Thunks

Async thunks are used to handle asynchronous logic in Redux. They can be dispatched like regular actions and handle the lifecycle of an async request.

import { createAsyncThunk } from '@reduxjs/toolkit';

const fetchUserById = createAsyncThunk(
  'users/fetchByIdStatus',
  async (userId, thunkAPI) => {
    const response = await fetch(`https://api.example.com/users/${userId}`);
    return await response.json();
  }
);

Immutable Update Logic

The toolkit enables writing reducers with simpler immutable update logic using the Immer library under the hood.

import { createReducer } from '@reduxjs/toolkit';

const counterReducer = createReducer(0, {
  increment: state => state + 1,
  decrement: state => state - 1
});

Other packages similar to @reduxjs/toolkit

redux-thunk

redux-thunk is a middleware that allows you to write action creators that return a function instead of an action. It is less feature-rich compared to @reduxjs/toolkit, which includes thunk functionality out of the box.

redux-saga

redux-saga is a library that aims to make application side effects (i.e., asynchronous things like data fetching and impure things like accessing the browser cache) easier to manage, more efficient to execute, easy to test, and better at handling failures. It uses a different approach than @reduxjs/toolkit's thunks, relying on ES6 generators.

immer

immer is a package that allows you to work with immutable state in a more convenient way by writing code that mutates the state. @reduxjs/toolkit uses Immer internally to simplify reducer logic.

reselect

reselect is a library for creating memoized, composable selector functions. @reduxjs/toolkit does not include it by default but is often used alongside it for optimizing state selection.

README

Redux Toolkit

The official, opinionated, batteries-included toolset for efficient Redux development

npm install @reduxjs/toolkit

(Formerly known as "Redux Starter Kit")

Purpose

The Redux Toolkit package is intended to be the standard way to write Redux logic. It was originally created to help address three common concerns about Redux:

• "Configuring a Redux store is too complicated"
• "I have to add a lot of packages to get Redux to do anything useful"
• "Redux requires too much boilerplate code"

We can't solve every use case, but in the spirit of create-react-app and apollo-boost, we can try to provide some tools that abstract over the setup process and handle the most common use cases, as well as include some useful utilities that will let the user simplify their application code.

This package is not intended to solve every possible use case for Redux, and is deliberately limited in scope. It does not address concepts like "reusable encapsulated Redux modules", data fetching, folder or file structures, managing entity relationships in the store, and so on.

What's Included

Redux Toolkit includes:

• A configureStore() function with simplified configuration options. It can automatically combine your slice reducers, adds whatever Redux middleware you supply, includes redux-thunk by default, and enables use of the Redux DevTools Extension.
• A createReducer() utility that lets you supply a lookup table of action types to case reducer functions, rather than writing switch statements. In addition, it automatically uses the immer library to let you write simpler immutable updates with normal mutative code, like state.todos[3].completed = true.
• A createAction() utility that returns an action creator function for the given action type string. The function itself has toString() defined, so that it can be used in place of the type constant.
• A createSlice() function that accepts a set of reducer functions, a slice name, and an initial state value, and automatically generates corresponding action creators, types, and simple selector functions.
• The createSelector utility from the Reselect library, re-exported for ease of use.

Documentation

The Redux Toolkit docs are available at https://redux-toolkit.js.org.