Made build portable

dependencies/fluent_ui-3.12.0/test/expander_test.dart

@@ -0,0 +1,23 @@
+import 'package:fluent_ui/fluent_ui.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'app_test.dart';
+
+void main() {
+  final expanderKey = GlobalKey<ExpanderState>();
+
+  testWidgets('Expander intiallyExpanded works properly', (tester) async {
+    await tester.pumpWidget(
+      wrapApp(
+        child: Expander(
+          key: expanderKey,
+          initiallyExpanded: true,
+          header: const Text('Header'),
+          content: const Text('Content'),
+        ),
+      ),
+    );
+
+    expect(expanderKey.currentState!.open, true);
+  });
+}