JQuery: Add return value of .offset() method

Definitions/jquery-1.8.d.ts

@@ -382,7 +382,7 @@ interface JQuery {
     innerHeight(): number;
     innerWidth(): number;
 
-    offset(): Object;
+    offset(): { left: number; top: number; };
     offset(coordinates: any): JQuery;
     offset(func: (index: any, coords: any) => any): JQuery;