reduxjs/redux-toolkit v1.9.0-rc.0

on GitHub

This release candidate includes a new "auto-batching" store enhancer, support for passing some global options to fetchBaseQuery, a fix for forceRefetch behavior, and internal tweaks to checks for missing RTKQ middleware setup.

Please try this out and give us feedback (even if it's just "tried updating and everything's fine")! If no further issues come up we intend to publish 1.9 in the next few days.

npm i @reduxjs/toolkit@next

yarn add @reduxjs/toolkit@next

Docs updates for 1.9 are complete, and can be viewed here:

https://deploy-preview-2401--redux-starter-kit-docs.netlify.app/

Changelog

New Auto-Batching Store Enhancer

There are several different ways to "batch actions" with Redux stores, ranging from reducers to debounced subscriber notifications.

RTK now includes a new autoBatchEnhancer() store enhancer that uses a variation on the "debounced notification" approach, inspired by React's technique of batching renders and determining if an update is low-priority or high-priority.

The enhancer looks for any actions tagged with an action.meta[SHOULD_AUTOBATCH] = true flag, and delays notifying subscribers until the end of the event loop tick. This means that if multiple "auto-batched" actions are dispatched in a row, there will be only one subscriber notification. However, if any "normal-priority" action without that flag is dispatched in the same tick, the enhancer will notify subscribers immediately.

This allows Redux users to selectively tag certain actions for effective batching behavior, making this purely opt-in on a per-action basis, while retaining normal notification behavior for all other actions.

RTK Query's internals have been updated to mark several key actions as batchable. While the enhancer is purely opt-in, benchmarks indicate that it can help speed up UI performance with RTK Query, especially when rendering many components with query hooks. We recommend adding it to your store setup:

  const store = configureStore({
  reducer,
  enhancers: (existingEnhancers) => {
    // Add the autobatch enhancer to the store setup
    return existingEnhancers.concat(autoBatchEnhancer())
  },
})

Additionally, there's a prepareAutoBatched util that can be used to help add the SHOULD_AUTOBATCH flag to actions, designed for use with createSlice:

const counterSlice = createSlice({
  name: 'counter',
  initialState: { value: 0 } as CounterState,
  reducers: {
    incrementBatched: {
      // Batched, low-priority
      reducer(state) {
        state.value += 1
      },
      // Use the `prepareAutoBatched` utility to automatically
      // add the `action.meta[SHOULD_AUTOBATCH]` field the enhancer needs
      prepare: prepareAutoBatched<void>(),
    },
    // Not batched, normal priority
    decrementUnbatched(state) {
      state.value -= 1
    },
  },
})

fetchBaseQuery Global Options

fetchBaseQuery now supports passing the responseHandler, validateStatus, and timeout options directly to fetchBaseQuery itself, in addition to accepting it as part of specific endpoints. If provided, these options will be applied as defaults to all requests for that API, which simplifies using them on many endpoints.

Other Changes

Providing serializeQueryArgs and forceRefetch options for an endpoint now works correctly when you pass an object as the cache key argument to a query hook.

The defaultSerializeQueryArgs util is now exported.

The endpoint-specific serializeQueryArgs option now allows returning an object or a number instead of just a string. If a string is returned, it will be used as-is for the serialized cache key. If an object or number is returned, that value will be passed to defaultSerializeQueryArgs. This simplifies the common case of wanting to remove a couple fields from the cache key, without needing to call defaultSerializeQueryArgs yourself.

Internal tweaks to the RTKQ middleware behavior for detecting cases where the middleware has not been added to the store.

The API docs for the 1.9 preview are fully updated.

What's Changed

• Fill out v1.9 remaining docs by @markerikson in #2804
• Rework endpoint serializeQueryArgs to allow object/number returns by @markerikson in #2835
• allow for global responseHandler and validateStatus configuration by @phryneas in #2823
• Fix refetches when sQA returns same value and queryArgs are object by @markerikson in #2844
• Add an auto-batching enhancer that delays low-pri notifications and use with RTKQ by @markerikson in #2846
• Check middleware registration directly to avoid persistence issues by @markerikson in #2850

Full Changelog: v1.9.0-beta.0...v1.9.0-rc.0