Type Redux store and middleware (#24843)

app/javascript/mastodon/store/index.ts

@@ -0,0 +1,23 @@
+import { configureStore } from '@reduxjs/toolkit';
+import { rootReducer } from '../reducers';
+import { loadingBarMiddleware } from './middlewares/loading_bar';
+import { errorsMiddleware } from './middlewares/errors';
+import { soundsMiddleware } from './middlewares/sounds';
+import { TypedUseSelectorHook, useDispatch, useSelector } from 'react-redux';
+
+export const store = configureStore({
+  reducer: rootReducer,
+  middleware: getDefaultMiddleware =>
+    getDefaultMiddleware().concat(
+      loadingBarMiddleware({ promiseTypeSuffixes: ['REQUEST', 'SUCCESS', 'FAIL'] }))
+      .concat(errorsMiddleware)
+      .concat(soundsMiddleware()),
+});
+
+// Infer the `RootState` and `AppDispatch` types from the store itself
+export type RootState = ReturnType<typeof rootReducer>
+// Inferred type: {posts: PostsState, comments: CommentsState, users: UsersState}
+export type AppDispatch = typeof store.dispatch
+
+export const useAppDispatch: () => AppDispatch = useDispatch;
+export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector;