Merge pull request #3867 from reduxjs/build-create-slice

Author: markerikson

docs/api/createSlice.mdx

@@ -138,7 +138,7 @@ const todosSlice = createSlice({
 
 Alternatively, the `reducers` field can be a callback which receives a "create" object.
 
-The main benefit of this is that you can create [async thunks](./createAsyncThunk) as part of your slice. Types are also slightly simplified for prepared reducers.
+The main benefit of this is that you can create [async thunks](./createAsyncThunk) as part of your slice (though for bundle size reasons, you [need a bit of setup for this](#createasyncthunk)). Types are also slightly simplified for prepared reducers.
 
 ```ts title="Creator callback for reducers"
 import { createSlice, nanoid } from '@reduxjs/toolkit'
@@ -240,6 +240,27 @@ create.preparedReducer(
 
 Creates an async thunk instead of an action creator.
 
+:::warning Setup
+
+To avoid pulling `createAsyncThunk` into the bundle size of `createSlice` by default, some extra setup is required to use `create.asyncThunk`.
+
+The version of `createSlice` exported from RTK will throw an error if `create.asyncThunk` is called.
+
+Instead, import `buildCreateSlice` and `asyncThunkCreator`, and create your own version of `createSlice`:
+
+```ts
+import { buildCreateSlice, asyncThunkCreator } from '@reduxjs/toolkit'
+
+// name is up to you
+export const createSliceWithThunks = buildCreateSlice({
+  creators: { asyncThunk: asyncThunkCreator },
+})
+```
+
+Then import this `createSlice` as needed instead of the exported version from RTK.
+
+:::
+
 **Parameters**
 
 - **payloadCreator** The thunk [payload creator](./createAsyncThunk#payloadcreator).

errors.json

@@ -33,5 +33,8 @@
   "31": "\"middleware\" field must be a callback",
   "32": "When using custom hooks for context, all  hooks need to be provided: .\\nHook  was either not provided or not a function.",
   "33": "Existing Redux context detected. If you already have a store set up, please use the traditional Redux setup.",
-  "34": "selectSlice returned undefined for an uninjected slice reducer"
+  "34": "selectSlice returned undefined for an uninjected slice reducer",
+  "35": "Cannot use `create.asyncThunk` in the built-in `createSlice`. Use `buildCreateSlice({ creators: { asyncThunk: asyncThunkCreator } })` to create a customised version of `createSlice`.",
+  "36": "`context.addCase` cannot be called with an empty action type",
+  "37": "`context.addCase` cannot be called with two reducers for the same action type: type"
 }

packages/toolkit/src/createAsyncThunk.ts

@@ -487,7 +487,7 @@ type CreateAsyncThunk<CurriedThunkApiConfig extends AsyncThunkConfig> = {
   >
 }
 
-export const createAsyncThunk = (() => {
+export const createAsyncThunk = /* @__PURE__ */ (() => {
   function createAsyncThunk<
     Returned,
     ThunkArg,