Improvements to notifications screen [APP-520] (#501)

* Refresh or sync notifications when the tab is navigated to

* Fix to bad textnode render

* Speed up initial session load

* Fix lint

* Restore updateSessionState() on session resumption

src/view/screens/Notifications.tsx

@@ -13,6 +13,7 @@ import {InvitedUsers} from '../com/notifications/InvitedUsers'
 import {LoadLatestBtn} from 'view/com/util/load-latest/LoadLatestBtn'
 import {useStores} from 'state/index'
 import {useOnMainScroll} from 'lib/hooks/useOnMainScroll'
+import {useTabFocusEffect} from 'lib/hooks/useTabFocusEffect'
 import {s} from 'lib/styles'
 import {useAnalytics} from 'lib/analytics'
 
@@ -58,6 +59,27 @@ export const NotificationsScreen = withAuthRequired(
         }
       }, [store, screen, onPressLoadLatest]),
     )
+    useTabFocusEffect(
+      'Notifications',
+      React.useCallback(
+        isInside => {
+          // on mobile:
+          // fires with `isInside=true` when the user navigates to the root tab
+          // but not when the user goes back to the screen by pressing back
+          // on web:
+          // essentially equivalent to useFocusEffect because we dont used tabbed
+          // navigation
+          if (isInside) {
+            if (store.me.notifications.unreadCount > 0) {
+              store.me.notifications.refresh()
+            } else {
+              store.me.notifications.syncQueue()
+            }
+          }
+        },
+        [store],
+      ),
+    )
 
     return (
       <View testID="notificationsScreen" style={s.hContentRegion}>

src/view/shell/desktop/LeftNav.tsx

@@ -95,11 +95,11 @@ const NavItem = observer(
         <Link href={href} style={styles.navItem}>
           <View style={[styles.navItemIconWrapper]}>
             {isCurrent ? iconFilled : icon}
-            {typeof count === 'string' && count && (
+            {typeof count === 'string' && count ? (
               <Text type="button" style={styles.navItemCount}>
                 {count}
               </Text>
-            )}
+            ) : null}
           </View>
           <Text type="title" style={[isCurrent ? s.bold : s.normal, pal.text]}>
             {label}