Improve basic dispatch signature. Fix typescript tests.

Author: Igorbek

index.d.ts

@@ -94,7 +94,7 @@ export function combineReducers<S>(reducers: ReducersMapObject): Reducer<S>;
  * before passing them to the next middleware.
  */
 export interface Dispatch<S> {
-    (action: Action): Action;
+    <A extends Action>(action: A): A;
 }
 
 /**
@@ -267,7 +267,7 @@ export interface MiddlewareAPI<S> {
  * asynchronous API call into a series of synchronous actions.
  */
 export interface Middleware {
-  <S>(api: MiddlewareAPI<S>): (next: Dispatch<S>) => any;
+  <S>(api: MiddlewareAPI<S>): (next: Dispatch<S>) => Dispatch<S>;
 }
 
 /**

test/typescript/actionCreators.ts

@@ -15,15 +15,15 @@ const addTodo: ActionCreator<AddTodoAction> = (text: string) => ({
 
 const addTodoAction: AddTodoAction = addTodo('test');
 
-type AddTodoThunk = (dispatch: Dispatch) => AddTodoAction;
+type AddTodoThunk = (dispatch: Dispatch<any>) => AddTodoAction;
 
 const addTodoViaThunk: ActionCreator<AddTodoThunk> = (text: string) =>
-  (dispatch: Dispatch) => ({
+  (dispatch: Dispatch<any>) => ({
     type: 'ADD_TODO',
     text
   })
 
-declare const dispatch: Dispatch;
+declare const dispatch: Dispatch<any>;
 
 const boundAddTodo = bindActionCreators(addTodo, dispatch);
 

test/typescript/dispatch.ts

@@ -13,3 +13,4 @@ declare module "../../index.d.ts" {
 }
 
 const dispatchThunkResult: number = dispatch(() => 42);
+const dispatchedTimerId: number = dispatch(d => setTimeout(() => d({type: 'TYPE'}), 1000));