v1.9.0-beta.0

This feature-complete preview release includes several new options for RTK Query API endpoints as well as the ability to "upsert" data, performance improvements to the RTK Query middleware, improvements to fetchBaseQuery behavior, several TS types tweaks and additional type exports, a runtime deprecation warning for the object argument form of createReducer and createSlice.extraReducers, and codemods to update those methods.

Please try this out and give us feedback (even if it's just "tried updating and everything's fine")! We believe that all changes intended for 1.9 are stable and should work, but as always we'd appreciate real-world checks to confirm that.

npm i @reduxjs/toolkit@next

yarn add @reduxjs/toolkit@next

Docs updates for 1.9 are in progress and can be viewed here:

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

Changes Since Alpha

Codemods for Deprecated Object Reducer Syntax

Per the description in 1.9.0-alpha.0, we plan to remove the "object" argument from createReducer and createSlice.extraReducers in the future RTK 2.0 major version. In 1.9.0-alpha.0, we added a one-shot runtime warning to each of those APIs.

To simplify upgrading codebases, we've published a set of codemods that will automatically transform the deprecated "object" syntax into the equivalent "builder" syntax.

The codemods package is available on NPM as @reduxjs/rtk-codemods. It currently contains two codemods: createReducerBuilder and createSliceBuilder.

To run the codemods against your codebase, run npx @reduxjs/rtk-codemods <TRANSFORM NAME> path/of/files/ or/some**/*glob.js.

Examples:

npx @reduxjs/rtk-codemods createReducerBuilder ./src

npx @reduxjs/rtk-codemods createSliceBuilder ./packages/my-app/**/*.ts

We also recommend re-running Prettier on the codebase before committing the changes.

These codemods should work, but we would greatly appreciate testing and feedback on more real-world codebases!

Before:

createReducer(initialState, {
  [todoAdded1a]: (state, action) => {
    // stuff
  },
  [todoAdded1b]: (state, action) => action.payload,
});

const slice1 = createSlice({
  name: "a",
  initialState: {},
  extraReducers: {
    [todoAdded1a]: (state, action) => {
      // stuff
    },
    [todoAdded1b]: (state, action) => action.payload,
  }
})

After:

createReducer(initialState, (builder) => {
  builder.addCase(todoAdded1a, (state, action) => {
    // stuff
  });

  builder.addCase(todoAdded1b, (state, action) => action.payload);
})

const slice1 = createSlice({
  name: "a",
  initialState: {},

  extraReducers: (builder) => {
    builder.addCase(todoAdded1a, (state, action) => {
      // stuff
    });

    builder.addCase(todoAdded1b, (state, action) => action.payload);
  }
})

getRunningOperationPromises Deprecation and Replacement

In v1.7.0, we added an api.util.getRunningOperationPromises() method for use with SSR scenarios, as well as a singular getRunningOperationPromise() method intended for possible use with React Suspense.

Unfortunately, in #2477 we realized that both those methods have a fatal flaw - they do not work with multiple stores in SSR.

As of this release, we are immediately marking getRunningOperationPromises() as deprecated and discouraging its use before we remove it completely in RTK 2.0! It will now throw both runtime and compile errors in development to enforce moving away from using it. However, we are leaving its existing behavior in production builds to avoid actual breakage.

The getRunningOperationPromise() util was experimental, and as far as we can tell not actually being used by anyone, so we are removing getRunningOperationPromise completely in this release.

As replacements, RTKQ now includes four new thunks attached to api.util:

• getRunningQueryThunk(endpointName, queryArgs)
• getRunningMutationThunk(endpointName, fixedCacheKeyOrRequestId)
• getRunningQueriesThunk()
• getRunningMutationsThunk()

Usages would typically change like this:

-await Promise.all(api.util.getRunningOperationPromises())
+await Promise.all(dispatch(api.util.getRunningQueriesThunk()))

Summary of Alpha Changes

See the previous release notes for more details.

RTK Query Options

• API endpoints:
  • serializeQueryArgs option ( #2493 )
  • merge option ( #1059 )
  • forceRefetch option ( #2663 )
  • transformErrorResponse option ( #1841
• upsertQueryData util ( #2266 )
• RTKQ middleware optimization ( #2641, #2759 )
• fetchBaseQuery options:
  • jsonContentType ( #2403 )
  • timeout ( #2363 )
  • content-type response handler ( #2363 )
  • prepareHeaders can return void ( #2775 )
• hook triggers return promises ( #2212 )
• retry conditions by response ( #2239 )

TS Types

• action types are now template literals ( #2250 )
• Store enhancer types ( #2550 )
• createAsyncThunk.withTypes ( #2604 )
• Several additional exported types:
  • #2276
  • #1646
  • #2740

TS Support Matrix

Redux Toolkit now requires TypeScript 4.2 or higher, and works correctly with TS 4.8.