refactor(test): Use helper for finding elements in UserTile

Author: vinodsingh-dev-gsoc

test/widgets/new_dm_sheet_test.dart

@@ -254,19 +254,19 @@ void main() {
   });
 
   group('user selection', () {
-    void checkUserSelected(WidgetTester tester, User user, bool expected) {
-      final icon = tester.widget<Icon>(find.descendant(
-        of: findUserTile(user),
-        matching: find.byType(Icon)));
-
-      if (expected) {
-        check(findUserChip(user)).findsOne();
-        check(icon).icon.equals(ZulipIcons.check_circle_checked);
-      } else {
-        check(findUserChip(user)).findsNothing();
-        check(icon).icon.equals(ZulipIcons.check_circle_unchecked);
+      Finder findInUserTile(User user, Finder finder) => find.descendant(of: findUserTile(user), matching: finder);
+
+      void checkUserSelected(WidgetTester tester, User user, bool expected) {
+        if (expected) {
+          check(findUserChip(user)).findsOne();
+          check(findInUserTile(user,find.byIcon(ZulipIcons.check_circle_checked))).findsOne();
+          check(findInUserTile(user,find.byIcon(ZulipIcons.check_circle_unchecked))).findsNothing();
+        } else {
+          check(findUserChip(user)).findsNothing();
+          check(findInUserTile(user,find.byIcon(ZulipIcons.check_circle_unchecked))).findsOne();
+          check(findInUserTile(user,find.byIcon(ZulipIcons.check_circle_checked))).findsNothing();
+        }
       }
-    }
 
     testWidgets('tapping user chip deselects the user', (tester) async {
       await setupSheet(tester, users: [eg.otherUser, eg.thirdUser]);