Fix hot reloading issues by removing the store from window

README.md

@@ -214,7 +214,6 @@ The `createWrapper` function accepts `makeStore` as its first argument. The `mak
 
 `createWrapper` also optionally accepts a config object as a second parameter:
 
-- `storeKey` (optional, string) : the key used on `window` to persist the store on the client
 - `debug` (optional, boolean) : enable debug logging
 - `serializeState` and `deserializeState`: custom functions for serializing and deserializing the redux state, see
     [Custom serialization and deserialization](#custom-serialization-and-deserialization).

packages/wrapper/src/index.tsx

@@ -12,7 +12,6 @@ import {
 } from 'next';
 
 export const HYDRATE = '__NEXT_REDUX_WRAPPER_HYDRATE__';
-export const STOREKEY = '__NEXT_REDUX_WRAPPER_STORE__';
 
 const getIsServer = () => typeof window === 'undefined';
 
@@ -22,19 +21,16 @@ const getDeserializedState = <S extends Store>(initialState: any, {deserializeSt
 const getSerializedState = <S extends Store>(state: any, {serializeState}: Config<S> = {}) =>
     serializeState ? serializeState(state) : state;
 
-const getStoreKey = <S extends Store>({storeKey}: Config<S> = {}) => storeKey || STOREKEY;
-
 export declare type MakeStore<S extends Store> = (context: Context) => S;
 
 export interface InitStoreOptions<S extends Store> {
     makeStore: MakeStore<S>;
     context: Context;
-    config: Config<S>;
 }
 
-const initStore = <S extends Store>({makeStore, context, config}: InitStoreOptions<S>): S => {
-    const storeKey = getStoreKey(config);
+let store: any;
 
+const initStore = <S extends Store>({makeStore, context}: InitStoreOptions<S>): S => {
     const createStore = () => makeStore(context);
 
     if (getIsServer()) {
@@ -48,15 +44,16 @@ const initStore = <S extends Store>({makeStore, context, config}: InitStoreOptio
             if (!req.__nextReduxWrapperStore) req.__nextReduxWrapperStore = createStore();
             return req.__nextReduxWrapperStore;
         }
+
         return createStore();
     }
 
     // Memoize store if client
-    if (!(storeKey in window)) {
-        (window as any)[storeKey] = createStore();
+    if (!store) {
+        store = createStore();
     }
 
-    return (window as any)[storeKey];
+    return store;
 };
 
 export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config: Config<S> = {}) => {
@@ -67,7 +64,7 @@ export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config:
         callback: Callback<S, any>;
         context: any;
     }): Promise<WrapperProps> => {
-        const store = initStore({context, makeStore, config});
+        const store = initStore({context, makeStore});
 
         if (config.debug) console.log(`1. getProps created store with state`, store.getState());
 
@@ -141,7 +138,7 @@ export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config:
                 const initialStateFromGSPorGSSR = props?.pageProps?.initialState;
 
                 if (!this.store) {
-                    this.store = initStore({makeStore, config, context});
+                    this.store = initStore({makeStore, context});
 
                     if (config.debug)
                         console.log('4. WrappedApp created new store with', displayName, {
@@ -232,7 +229,6 @@ export type Context = NextPageContext | AppContext | GetStaticPropsContext | Get
 export interface Config<S extends Store> {
     serializeState?: (state: ReturnType<S['getState']>) => any;
     deserializeState?: (state: any) => ReturnType<S['getState']>;
-    storeKey?: string;
     debug?: boolean;
 }
 

packages/wrapper/tests/client.spec.tsx

@@ -3,27 +3,26 @@
  **/
 
 import * as React from 'react';
+import {useDispatch} from 'react-redux';
+import {create, act} from 'react-test-renderer';
 import {DummyComponent, wrapper, child, makeStore} from './testlib';
 import {createWrapper} from '../src';
 import {Store} from 'redux';
 
-const w: {testStoreKey?: Store} = window as any;
+let store: Store;
 
 const defaultState = {reduxStatus: 'init'};
+const modifiedState = {...defaultState, modified: true};
 
 describe('client integration', () => {
-    afterEach(() => {
-        delete w.testStoreKey;
-    });
-
     describe('existing store is taken from window', () => {
         beforeEach(() => {
-            w.testStoreKey = makeStore();
+            store = makeStore();
         });
 
         test('withRedux', async () => {
             const WrappedPage: any = wrapper.withRedux(DummyComponent);
-            expect(child(<WrappedPage initialState={w.testStoreKey?.getState()} />)).toEqual(
+            expect(child(<WrappedPage initialState={store.getState()} />)).toEqual(
                 '{"props":{},"state":{"reduxStatus":"init"}}',
             );
         });
@@ -38,11 +37,32 @@ describe('client integration', () => {
         });
     });
 
-    test('store is available in window when created', async () => {
-        const wrapper = createWrapper(makeStore, {storeKey: 'testStoreKey'});
-        const Page = () => null;
-        Page.getInitialProps = wrapper.getInitialPageProps(store => () => null);
+    test('store is available when calling getInitialProps client-side and references the existing store on client', async () => {
+        const wrapper = createWrapper(makeStore);
+        let renderer: any = null;
+
+        const Page: React.ComponentType<any> & {getInitialProps: any} = () => {
+            const dispatch = useDispatch();
+
+            React.useEffect(() => {
+                // modifies the state,
+                dispatch({type: 'MODIFY_STATE'});
+            }, []);
+
+            return null;
+        };
+        Page.getInitialProps = wrapper.getInitialPageProps(store => () =>
+            // when invoked below, verify that state modification is retained in getInitialProps
+            expect(store.getState()).toEqual(modifiedState),
+        );
+
+        const Wrapped: any = wrapper.withRedux(Page);
+
+        act(() => {
+            renderer = create(<Wrapped />);
+        });
+
+        // expected when invoked above
         await wrapper.withRedux(Page)?.getInitialProps({} as any);
-        expect(w.testStoreKey?.getState()).toEqual(defaultState);
     });
 });

packages/wrapper/tests/server.spec.tsx

@@ -152,7 +152,7 @@ describe('custom serialization', () => {
             },
         });
 
-        const WrappedApp = wrapper.withRedux(DummyComponent);
+        const WrappedApp: any = wrapper.withRedux(DummyComponent);
 
         expect(child(<WrappedApp {...props} />)).toEqual(
             '{"props":{},"state":{"reduxStatus":"init","serialized":true,"deserialized":true}}',

packages/wrapper/tests/testlib.tsx

@@ -17,16 +17,18 @@ export const reducer = (state: State = {reduxStatus: 'init'}, action: AnyAction)
         case 'FOO': // sync
         case 'FOO_FULFILLED': // async
             return {reduxStatus: action.payload};
+        case 'MODIFY_STATE':
+            return {...state, modified: true};
         default:
             return state;
     }
 };
 
 export const makeStore = () => createStore(reducer, undefined, applyMiddleware(promiseMiddleware));
 
-export const wrapper = createWrapper(makeStore, {storeKey: 'testStoreKey'});
+export const wrapper = createWrapper(makeStore);
 
-export const DummyComponent = (props: any) => {
+export const DummyComponent: React.ComponentType<any> = (props: any) => {
     const state = useSelector((state: State) => state);
     return <div>{JSON.stringify({props, state})}</div>;
 };