Re-landing SliverAnimatedList (#42485)

packages/flutter/test/widgets/animated_list_test.dart

@@ -6,13 +6,67 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/widgets.dart';
 
 void main() {
-  testWidgets('AnimatedList initialItemCount', (WidgetTester tester) async {
-    final Map<int, Animation<double>> animations = <int, Animation<double>>{};
+  testWidgets('AnimatedList', (WidgetTester tester) async {
+    final AnimatedListItemBuilder builder = (BuildContext context, int index, Animation<double> animation) {
+      return SizedBox(
+        height: 100.0,
+        child: Center(
+          child: Text('item $index'),
+        ),
+      );
+    };
+    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
 
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: AnimatedList(
+          key: listKey,
+          initialItemCount: 2,
+          itemBuilder: builder,
+        ),
+      ),
+    );
+
+    expect(find.byWidgetPredicate((Widget widget) {
+      return widget is SliverAnimatedList
+         && widget.initialItemCount == 2
+         && widget.itemBuilder == builder;
+    }), findsOneWidget);
+
+    listKey.currentState.insertItem(0);
+    await tester.pump();
+    expect(find.text('item 2'), findsOneWidget);
+
+    listKey.currentState.removeItem(
+      2,
+      (BuildContext context, Animation<double> animation) {
+        return const SizedBox(
+          height: 100.0,
+          child: Center(child: Text('removing item')),
+        );
+      },
+      duration: const Duration(milliseconds: 100),
+    );
+
+    await tester.pump();
+    expect(find.text('removing item'), findsOneWidget);
+    expect(find.text('item 2'), findsNothing);
+
+    await tester.pumpAndSettle(const Duration(milliseconds: 100));
+    expect(find.text('removing item'), findsNothing);
+  });
+
+  group('SliverAnimatedList', () {
+    testWidgets('initialItemCount', (WidgetTester tester) async {
+      final Map<int, Animation<double>> animations = <int, Animation<double>>{};
+
+      await tester.pumpWidget(
+        Directionality(
+          textDirection: TextDirection.ltr,
+          child: CustomScrollView(
+            slivers: <Widget>[
+              SliverAnimatedList(
                 initialItemCount: 2,
                 itemBuilder: (BuildContext context, int index, Animation<double> animation) {
                   animations[index] = animation;
@@ -23,6 +77,8 @@ void main() {
                     ),
                   );
                 },
+              )
+            ],
           ),
         ),
       );
@@ -35,13 +91,15 @@ void main() {
       expect(animations[1].value, 1.0);
     });
 
-  testWidgets('AnimatedList insert', (WidgetTester tester) async {
-    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
+    testWidgets('insert', (WidgetTester tester) async {
+      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
 
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
-        child: AnimatedList(
+          child: CustomScrollView(
+            slivers: <Widget>[
+              SliverAnimatedList(
                 key: listKey,
                 itemBuilder: (BuildContext context, int index, Animation<double> animation) {
                   return SizeTransition(
@@ -50,12 +108,12 @@ void main() {
                     sizeFactor: animation,
                     child: SizedBox(
                       height: 100.0,
-                child: Center(
-                  child: Text('item $index'),
-                ),
+                      child: Center(child: Text('item $index')),
                     ),
                   );
                 },
+              )
+            ],
           ),
         ),
       );
@@ -64,7 +122,10 @@ void main() {
       double itemTop(int index) => tester.getTopLeft(find.byKey(ValueKey<int>(index), skipOffstage: false)).dy;
       double itemBottom(int index) => tester.getBottomLeft(find.byKey(ValueKey<int>(index), skipOffstage: false)).dy;
 
-    listKey.currentState.insertItem(0, duration: const Duration(milliseconds: 100));
+      listKey.currentState.insertItem(
+        0,
+        duration: const Duration(milliseconds: 100),
+      );
       await tester.pump();
 
       // Newly inserted item 0's height should animate from 0 to 100
@@ -79,11 +140,18 @@ void main() {
       expect(itemTop(0), 0.0);
       expect(itemBottom(0), 100.0);
 
-    listKey.currentState.insertItem(0, duration: const Duration(milliseconds: 100));
-    listKey.currentState.insertItem(0, duration: const Duration(milliseconds: 100));
+      listKey.currentState.insertItem(
+        0,
+        duration: const Duration(milliseconds: 100),
+      );
+      listKey.currentState.insertItem(
+        0,
+        duration: const Duration(milliseconds: 100),
+      );
       await tester.pump();
 
-    // The height of the newly inserted items at index 0 and 1 should animate from 0 to 100.
+      // The height of the newly inserted items at index 0 and 1 should animate
+      // from 0 to 100.
       // The height of the original item, now at index 2, should remain 100.
       expect(itemHeight(0), 0.0);
       expect(itemHeight(1), 0.0);
@@ -109,8 +177,8 @@ void main() {
       expect(itemBottom(2), 300.0);
     });
 
-  testWidgets('AnimatedList remove', (WidgetTester tester) async {
-    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
+    testWidgets('remove', (WidgetTester tester) async {
+      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
       final List<int> items = <int>[0, 1, 2];
 
       Widget buildItem(BuildContext context, int item, Animation<double> animation) {
@@ -130,12 +198,16 @@ void main() {
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
-        child: AnimatedList(
+          child: CustomScrollView(
+            slivers: <Widget>[
+              SliverAnimatedList(
                 key: listKey,
                 initialItemCount: 3,
                 itemBuilder: (BuildContext context, int index, Animation<double> animation) {
                   return buildItem(context, items[index], animation);
                 },
+              )
+            ],
           ),
         ),
       );
@@ -148,7 +220,8 @@ void main() {
       expect(find.text('item 2'), findsOneWidget);
 
       items.removeAt(0);
-    listKey.currentState.removeItem(0,
+      listKey.currentState.removeItem(
+        0,
         (BuildContext context, Animation<double> animation) => buildItem(context, 0, animation),
         duration: const Duration(milliseconds: 100),
       );
@@ -180,4 +253,70 @@ void main() {
       expect(itemTop(2), 100.0);
       expect(itemBottom(2), 200.0);
     });
+
+    testWidgets('works in combination with other slivers', (WidgetTester tester) async {
+      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
+
+      await tester.pumpWidget(
+        Directionality(
+          textDirection: TextDirection.ltr,
+          child: CustomScrollView(
+            slivers: <Widget>[
+              SliverList(
+                delegate: SliverChildListDelegate(<Widget>[
+                  const SizedBox(height: 100),
+                  const SizedBox(height: 100),
+                ]),
+              ),
+              SliverAnimatedList(
+                key: listKey,
+                initialItemCount: 3,
+                itemBuilder: (BuildContext context, int index, Animation<double> animation) {
+                  return SizedBox(
+                    height: 100,
+                    child: Text('item $index'),
+                  );
+                },
+              ),
+            ],
+          ),
+        ),
+      );
+
+      expect(tester.getTopLeft(find.text('item 0')).dy, 200);
+      expect(tester.getTopLeft(find.text('item 1')).dy, 300);
+
+      listKey.currentState.insertItem(3);
+      await tester.pumpAndSettle();
+      expect(tester.getTopLeft(find.text('item 3')).dy, 500);
+
+      listKey.currentState.removeItem(0,
+        (BuildContext context, Animation<double> animation) {
+          return SizeTransition(
+            sizeFactor: animation,
+            key: const ObjectKey('removing'),
+            child: const SizedBox(
+              height: 100,
+              child: Text('removing'),
+            ),
+          );
+        },
+        duration: const Duration(seconds: 1),
+      );
+
+      await tester.pump();
+      expect(find.text('item 3'), findsNothing);
+
+      await tester.pump(const Duration(milliseconds: 500));
+      expect(
+        tester.getSize(find.byKey(const ObjectKey('removing'))).height,
+        50,
+      );
+      expect(tester.getTopLeft(find.text('item 0')).dy, 250);
+
+      await tester.pumpAndSettle();
+      expect(find.text('removing'), findsNothing);
+      expect(tester.getTopLeft(find.text('item 0')).dy, 200);
+    });
+  });
 }