configureStore

configureStore

A friendly abstraction over the standard Redux createStore function that adds good defaults to the store setup for a better development experience.

Parameters

configureStore accepts a single configuration object parameter, with the following options:

type ConfigureEnhancersCallback = (
  defaultEnhancers: StoreEnhancer[]
) => StoreEnhancer[]

interface ConfigureStoreOptions<
  S = any,
  A extends Action = AnyAction,
  M extends Middlewares<S> = Middlewares<S>
> {
  /**
   * A single reducer function that will be used as the root reducer, or an
   * object of slice reducers that will be passed to `combineReducers()`.
   */
  reducer: Reducer<S, A> | ReducersMapObject<S, A>

  /**
   * An array of Redux middleware to install. If not supplied, defaults to
   * the set of middleware returned by `getDefaultMiddleware()`.
   */
  middleware?: ((getDefaultMiddleware: CurriedGetDefaultMiddleware<S>) => M) | M

  /**
   * Whether to enable Redux DevTools integration. Defaults to `true`.
   *
   * Additional configuration can be done by passing Redux DevTools options
   */
  devTools?: boolean | DevToolsOptions

  /**
   * The initial state, same as Redux's createStore.
   * You may optionally specify it to hydrate the state
   * from the server in universal apps, or to restore a previously serialized
   * user session. If you use `combineReducers()` to produce the root reducer
   * function (either directly or indirectly by passing an object as `reducer`),
   * this must be an object with the same shape as the reducer map keys.
   */
  preloadedState?: DeepPartial<S extends any ? S : S>

  /**
   * The store enhancers to apply. See Redux's `createStore()`.
   * All enhancers will be included before the DevTools Extension enhancer.
   * If you need to customize the order of enhancers, supply a callback
   * function that will receive the original array (ie, `[applyMiddleware]`),
   * and should return a new array (such as `[applyMiddleware, offline]`).
   * If you only need to add middleware, you can use the `middleware` parameter instead.
   */
  enhancers?: StoreEnhancer[] | ConfigureEnhancersCallback
}

function configureStore<S = any, A extends Action = AnyAction>(
  options: ConfigureStoreOptions<S, A>
): EnhancedStore<S, A>

reducer

If this is a single function, it will be directly used as the root reducer for the store.

If it is an object of slice reducers, like {users : usersReducer, posts : postsReducer}, configureStore will automatically create the root reducer by passing this object to the Redux combineReducers utility.

middleware

An optional array of Redux middleware functions

If this option is provided, it should contain all the middleware functions you want added to the store. configureStore will automatically pass those to applyMiddleware.

If not provided, configureStore will call getDefaultMiddleware and use the array of middleware functions it returns.

Alternately, you may pass a callback function that will receive getDefaultMiddleware as its argument, and should return a middleware array. This lets you skip importing getDefaultMiddleware separately. If using TypeScript, prefer using this syntax, as we provide a more strongly-typed version of getDefaultMiddleware that will correctly retain the types of the provided middleware when constructing the store.

For more details on how the middleware parameter works and the list of middleware that are added by default, see the getDefaultMiddleware docs page.

devTools

If this is a boolean, it will be used to indicate whether configureStore should automatically enable support for the Redux DevTools browser extension.

If it is an object, then the DevTools Extension will be enabled, and the options object will be passed to composeWithDevtools(). See the DevTools Extension docs for EnhancerOptions for a list of the specific options that are available.

Defaults to true.

The Redux DevTools Extension recently added support for showing action stack traces that show exactly where each action was dispatched. Capturing the traces can add a bit of overhead, so the DevTools Extension allows users to configure whether action stack traces are captured.

If the DevTools are enabled by passing true or an object, then configureStore will default to enabling capturing action stack traces in development mode only.

preloadedState

An optional initial state value to be passed to the Redux createStore function.

enhancers

An optional array of Redux store enhancers, or a callback function to customize the array of enhancers.

If defined as an array, these will be passed to the Redux compose function, and the combined enhancer will be passed to createStore.

This should not include applyMiddleware() or the Redux DevTools Extension composeWithDevTools, as those are already handled by configureStore.

Example: enhancers: [offline] will result in a final setup of [applyMiddleware, offline, devToolsExtension].

If defined as a callback function, it will be called with the existing array of enhancers without the DevTools Extension (currently [applyMiddleware]), and should return a new array of enhancers. This is primarily useful for cases where a store enhancer needs to be added in front of applyMiddleware, such as redux-first-router or redux-offline.

Example: enhancers: (defaultEnhancers) => [offline, ...defaultEnhancers] will result in a final setup of [offline, applyMiddleware, devToolsExtension].

Usage

Basic Example

// file: reducers.ts noEmit
import { Reducer } from '@reduxjs/toolkit'
declare const rootReducer: Reducer<{}>
export default rootReducer

// file: store.ts
import { configureStore } from '@reduxjs/toolkit'

import rootReducer from './reducers'

const store = configureStore({ reducer: rootReducer })
// The store now has redux-thunk added and the Redux DevTools Extension is turned on

Full Example

// file: todos/todosReducer.ts noEmit
import { Reducer } from '@reduxjs/toolkit'
declare const reducer: Reducer<{}>
export default reducer

// file: visibility/visibilityReducer.ts noEmit
import { Reducer } from '@reduxjs/toolkit'
declare const reducer: Reducer<{}>
export default reducer

// file: store.ts
import { configureStore } from '@reduxjs/toolkit'

// We'll use redux-logger just as an example of adding another middleware
import logger from 'redux-logger'

// And use redux-batch as an example of adding enhancers
import { reduxBatch } from '@manaflair/redux-batch'

import todosReducer from './todos/todosReducer'
import visibilityReducer from './visibility/visibilityReducer'

const reducer = {
  todos: todosReducer,
  visibility: visibilityReducer,
}

const preloadedState = {
  todos: [
    {
      text: 'Eat food',
      completed: true,
    },
    {
      text: 'Exercise',
      completed: false,
    },
  ],
  visibilityFilter: 'SHOW_COMPLETED',
}

const store = configureStore({
  reducer,
  middleware: (getDefaultMiddleware) => getDefaultMiddleware().concat(logger),
  devTools: process.env.NODE_ENV !== 'production',
  preloadedState,
  enhancers: [reduxBatch],
})

// The store has been created with these options:
// - The slice reducers were automatically passed to combineReducers()
// - redux-thunk and redux-logger were added as middleware
// - The Redux DevTools Extension is disabled for production
// - The middleware, batch, and devtools enhancers were composed together