Fixing Typescript generic inconsistencies and "arrayMerger" parameter…

…s types (#273)

src/index.ts

@@ -11,15 +11,15 @@ interface Storage {
 interface Options<State> {
  key?: string;
  paths?: string[];
- reducer?: (state: any, paths: string[]) => object;
+ reducer?: (state: State, paths: string[]) => object;
  subscriber?: (
  store: Store<State>
- ) => (handler: (mutation: any, state: any) => void) => void;
+  ) => (handler: (mutation: any, state: State) => void) => void;
  storage?: Storage;
  getState?: (key: string, storage: Storage) => any;
- setState?: (key: string, state: Store<State>, storage: Storage) => void;
+ setState?: (key: string, state: any, storage: Storage) => void;
  filter?: (mutation: MutationPayload) => boolean;
- arrayMerger?: (state: any, saved: any) => any;
+ arrayMerger?: (state: any[], saved: any[]) => any;
  rehydrated?: (store: Store<State>) => void;
  fetchBeforeUse?: boolean;
  overwrite?: boolean;
@@ -85,7 +85,7 @@ export default function <State>(
  savedState = fetchSavedState();
  }
 
- return function (store) {
+ return function (store: Store<State>) {
  if (!options.fetchBeforeUse) {
  savedState = fetchSavedState();
  }