Merge pull request mobxjs#824 from newoga/feature/improve-flow-typing-action

Improve flow typing for action method

Author: mweststrate

flow-typed/mobx.js

@@ -301,6 +301,8 @@ declare module 'mobx' {
   declare function extendShallowObservable(target: any): any;
 
   declare function action(targetOrName: any, propertyKeyOrFuc?: any, descriptor?: PropertyDescriptor): any;
+  declare function action<T>(name: string, func: T): T;
+  declare function action<T>(func: T): T;
   declare function runInAction<T>(name: string, block: () => T, scope?: any): T;
   declare function runInAction<T>(block: () => T, scope?: any): T;
   declare function isAction(thing: any): boolean;