apply lint prefer_void_to_null in packages/flutter_tools (#22686)
diff --git a/packages/flutter_tools/lib/src/base/utils.dart b/packages/flutter_tools/lib/src/base/utils.dart
index ee485de..e74fd49 100644
--- a/packages/flutter_tools/lib/src/base/utils.dart
+++ b/packages/flutter_tools/lib/src/base/utils.dart
@@ -251,14 +251,14 @@
Clock get clock => context[Clock];
-typedef AsyncCallback = Future<Null> Function();
+typedef AsyncCallback = Future<void> Function();
/// A [Timer] inspired class that:
/// - has a different initial value for the first callback delay
/// - waits for a callback to be complete before it starts the next timer
class Poller {
Poller(this.callback, this.pollingInterval, { this.initialDelay = Duration.zero }) {
- Future<Null>.delayed(initialDelay, _handleCallback);
+ Future<void>.delayed(initialDelay, _handleCallback);
}
final AsyncCallback callback;
@@ -268,7 +268,7 @@
bool _cancelled = false;
Timer _timer;
- Future<Null> _handleCallback() async {
+ Future<void> _handleCallback() async {
if (_cancelled)
return;
