Export isDraft from Immer (#944)

Author: markerikson

docs/api/otherExports.mdx

@@ -52,6 +52,10 @@ const todosReducer = createReducer(initialState, builder => {
 })
 ```
 
+### `isDraft`
+
+[The `isDraft` function](https://immerjs.github.io/immer/original) from the [`immer` library](https://immerjs.github.io/immer/), which checks to see if a given value is a Proxy-wrapped "draft" state.
+
 ### `combineReducers`
 
 Redux's [`combineReducers`](https://redux.js.org/api/combinereducers), re-exported for convenience. While `configureStore` calls this internally, you may wish to call it yourself to compose multiple levels of slice reducers.

docs/usage/immer-reducers.md

@@ -386,7 +386,7 @@ The correct output would look like this instead:
 
 ![Logged current value](/img/usage/immer-reducers/logged-current-state.png)
 
-Immer also provides [`original` and `isDraft` functions](https://immerjs.github.io/immer/original), which retrieves the original data without any updates applied and check to see if a given value is a Proxy-wrapped draft. As of RTK 1.5.0, neither of those is re-exported - you'll need to specifically import them from `immer` yourself. We may re-export them from RTK in an upcoming release.
+Immer also provides [`original` and `isDraft` functions](https://immerjs.github.io/immer/original), which retrieves the original data without any updates applied and check to see if a given value is a Proxy-wrapped draft. As of RTK 1.5.1, both of those are re-exported from RTK as well.
 
 ### Updating Nested Data
 

etc/redux-toolkit.api.md

@@ -14,6 +14,7 @@ import { DeepPartial } from 'redux';
 import { Dispatch } from 'redux';
 import { Draft } from 'immer';
 import { freeze } from 'immer';
+import { isDraft } from 'immer';
 import { Middleware } from 'redux';
 import { original } from 'immer';
 import { OutputParametricSelector } from 'reselect';
@@ -315,6 +316,8 @@ export function isAsyncThunkAction<AsyncThunks extends [AnyAsyncThunk, ...AnyAsy
 // @public
 export function isAsyncThunkAction(action: any): action is UnknownAsyncThunkAction;
 
+export { isDraft }
+
 // @public
 export function isFulfilled(): (action: any) => action is UnknownAsyncThunkFulfilledAction;
 

src/immutablePerfBenchmarks.ts

@@ -5,7 +5,8 @@ export {
   Draft,
   current,
   freeze,
-  original
+  original,
+  isDraft
 } from 'immer'
 export {
   createSelector,