Fix Immer current usage when the value may not be a draft

packages/toolkit/src/entities/tests/sorted_state_adapter.test.ts

@@ -5,6 +5,7 @@ import {
   createSlice,
   configureStore,
   nanoid,
+  PayloadAction,
 } from '@reduxjs/toolkit'
 import type { BookModel } from './fixtures/book'
 import {
@@ -783,6 +784,30 @@ describe('Sorted State Adapter', () => {
     //expect(numSorts).toBeLessThan(25_000)
   })
 
+  it('should not throw an Immer `current` error when `state.ids` is a plain array', () => {
+    const book1: BookModel = { id: 'a', title: 'First' }
+    const initialState = adapter.getInitialState()
+    const withItems = adapter.addMany(initialState, [book1])
+    const booksSlice = createSlice({
+      name: 'books',
+      initialState,
+      reducers: {
+        testCurrentBehavior(state, action: PayloadAction<BookModel>) {
+          // Will overwrite `state.ids` with a plain array
+          adapter.removeAll(state)
+
+          // will call `splitAddedUpdatedEntities` and call `current(state.ids)`
+          adapter.upsertMany(state, [book1])
+        },
+      },
+    })
+
+    booksSlice.reducer(
+      initialState,
+      booksSlice.actions.testCurrentBehavior(book1),
+    )
+  })
+
   describe('can be used mutably when wrapped in createNextState', () => {
     test('removeAll', () => {
       const withTwo = adapter.addMany(state, [TheGreatGatsby, AnimalFarm])

packages/toolkit/src/entities/utils.ts

@@ -47,7 +47,7 @@ export function splitAddedUpdatedEntities<T, Id extends EntityId>(
 ): [T[], Update<T, Id>[], Id[]] {
   newEntities = ensureEntitiesArray(newEntities)
 
-  const existingIdsArray = current(state.ids) as Id[]
+  const existingIdsArray = getCurrent(state.ids) as Id[]
   const existingIds = new Set<Id>(existingIdsArray)
 
   const added: T[] = []