Adding window visibility check, removing generic sleep.

src/shared/components/app/navbar.tsx

@@ -410,6 +410,7 @@ export class Navbar extends Component<NavbarProps, NavbarState> {
 
   fetchUnreads() {
     poll(async () => {
+      if (window.document.visibilityState !== "hidden") {
         const auth = myAuth();
         if (auth) {
           this.setState({
@@ -435,6 +436,7 @@ export class Navbar extends Component<NavbarProps, NavbarState> {
             });
           }
         }
+      }
     }, updateUnreadCountsInterval);
   }
 

src/shared/utils.ts

@@ -1492,7 +1492,7 @@ export function newVote(voteType: VoteType, myVote?: number): number {
   }
 }
 
-function sleep<T>(millis: number): Promise<T> {
+function sleep(millis: number): Promise<void> {
   return new Promise(resolve => setTimeout(resolve, millis));
 }