test(ensemble): cover progress timer dispose and ListView scroll APIs

modules/ensemble/test/widget/list_view_test.dart

@@ -19,6 +19,69 @@ void main() {
     return widget;
   }
 
+  ensemble.ListView listViewWithManyChildren({int count = 20}) {
+    final widget = ensemble.ListView();
+    widget.initChildren(
+      children: List.generate(
+        count,
+        (i) => ViewUtil.buildModel({
+          'Text': {'text': 'Item $i'}
+        }, null),
+      ),
+    );
+    return widget;
+  }
+
+  test('scrollToOffset is a no-op without attached scroll clients', () {
+    final controller = ensemble.ListViewController();
+    final scrollController = ScrollController();
+    controller.scrollController = scrollController;
+
+    expect(() => controller.scrollToOffset(100), returnsNormally);
+
+    scrollController.dispose();
+  });
+
+  testWidgets('scrollToOffset jumps to pixel offset when not animated',
+      (tester) async {
+    final list = listViewWithManyChildren();
+
+    await tester.pumpWidget(TestUtils.wrapTestWidgetWithScope(
+      SizedBox(
+        height: 200,
+        width: 300,
+        child: list,
+      ),
+    ));
+    await tester.pumpAndSettle();
+
+    list.controller.scrollToOffset(80, animated: false);
+    await tester.pump();
+
+    expect(list.controller.scrollController!.offset, 80);
+  });
+
+  testWidgets('scrollToTop moves list to offset zero', (tester) async {
+    final list = listViewWithManyChildren();
+
+    await tester.pumpWidget(TestUtils.wrapTestWidgetWithScope(
+      SizedBox(
+        height: 200,
+        width: 300,
+        child: list,
+      ),
+    ));
+    await tester.pumpAndSettle();
+
+    list.controller.scrollToOffset(80, animated: false);
+    await tester.pump();
+    expect(list.controller.scrollController!.offset, greaterThan(0));
+
+    list.controller.scrollToTop(animated: false);
+    await tester.pump();
+    expect(list.controller.scrollController!.offset, 0);
+  });
+
   testWidgets('disposes internally-created scroll controller', (tester) async {
     final widget = ensemble.ListView();
 

modules/ensemble/test/widget/progress_indicator_test.dart

@@ -0,0 +1,34 @@
+import 'package:ensemble/widget/progress_indicator.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'test_utils.dart';
+
+void main() {
+  testWidgets('cancels countdown timers when removed from tree', (tester) async {
+    final widget = EnsembleProgressIndicator();
+    widget.setProperty('countdown', 2);
+
+    await tester.pumpWidget(TestUtils.wrapTestWidgetWithScope(widget));
+    await tester.pump();
+
+    await tester.pumpWidget(TestUtils.wrapTestWidget(const SizedBox.shrink()));
+    await tester.pump();
+
+    // Advance well past the countdown; leaked timers would call setState off-tree.
+    await tester.pump(const Duration(seconds: 5));
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('countdown updates progress after periodic tick', (tester) async {
+    final widget = EnsembleProgressIndicator();
+    widget.setProperty('countdown', 2);
+
+    await tester.pumpWidget(TestUtils.wrapTestWidgetWithScope(widget));
+    await tester.pump();
+
+    await tester.pump(const Duration(milliseconds: 150));
+    expect(widget.controller.value, isNotNull);
+    expect(widget.controller.value, greaterThan(0));
+  });
+}