Add exported ThunkAction type

Author: aikoven

index.d.ts

@@ -1,11 +1,12 @@
-import {Middleware} from "redux";
+import {Middleware, Dispatch} from "redux";
 
 
+export type ThunkAction<R, S, E> = (dispatch: Dispatch<S>, getState: () => S,
+                                    extraArgument: E) => R;
+
 declare module "redux" {
   export interface Dispatch<S> {
-    <R>(asyncAction: (dispatch: Dispatch<S>, 
-                      getState?: () => S, 
-                      extraArgument?: any) => R): R;
+    <R, E>(asyncAction: ThunkAction<R, S, E>): R;
   }
 }
 

test/typescript.ts

@@ -1,5 +1,5 @@
 import {Store, Middleware} from 'redux';
-import thunk from '../index.d.ts';
+import thunk, {ThunkAction} from '../index.d.ts';
 
 
 declare const store: Store<{foo: string}>;
@@ -19,3 +19,15 @@ const middleware: Middleware = thunk.withExtraArgument('bar');
 store.dispatch((dispatch, getState, extraArg) => {
   console.log(extraArg);
 });
+
+const thunkAction: ThunkAction<void, {foo: string}, {bar: number}> =
+  (dispatch, getState, extraArg) => {
+    const foo: string = getState().foo;
+    const bar: number = extraArg.bar;
+
+    dispatch({type: 'FOO'});
+  };
+
+const thunkActionDispatchOnly: ThunkAction<void, {}, {}> = dispatch => {
+  dispatch({type: 'FOO'});
+};