From ca1dbb949e881b0118baae6fcd8efa764e20b273 Mon Sep 17 00:00:00 2001
From: Kate Lovett <katelovett@google.com>
Date: Thu, 23 Sep 2021 17:33:05 -0500
Subject: [PATCH] Fix stretch recede edge case (#90629)

---
 .../lib/src/widgets/overscroll_indicator.dart |  3 +-
 .../overscroll_stretch_indicator_test.dart    | 34 ++++++++++++++++---
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/packages/flutter/lib/src/widgets/overscroll_indicator.dart b/packages/flutter/lib/src/widgets/overscroll_indicator.dart
index 341a90e1e36..d99e849624d 100644
--- a/packages/flutter/lib/src/widgets/overscroll_indicator.dart
+++ b/packages/flutter/lib/src/widgets/overscroll_indicator.dart
@@ -700,8 +700,7 @@ class _StretchingOverscrollIndicatorState extends State<StretchingOverscrollIndi
           }
         }
       }
-    } else if (notification is ScrollEndNotification && notification.dragDetails != null
-        || notification is ScrollUpdateNotification && notification.dragDetails != null) {
+    } else if (notification is ScrollEndNotification || notification is ScrollUpdateNotification) {
       _stretchController.scrollEnd();
     }
     _lastNotification = notification;
diff --git a/packages/flutter/test/widgets/overscroll_stretch_indicator_test.dart b/packages/flutter/test/widgets/overscroll_stretch_indicator_test.dart
index e7ca659e14e..33ad9cdff2a 100644
--- a/packages/flutter/test/widgets/overscroll_stretch_indicator_test.dart
+++ b/packages/flutter/test/widgets/overscroll_stretch_indicator_test.dart
@@ -97,7 +97,7 @@ void main() {
     expect(box3.localToGlobal(Offset.zero).dy, greaterThan(510.0));
     await expectLater(
       find.byType(CustomScrollView),
-      matchesGoldenFile('overscroll_stretch.vertical.top.png'),
+      matchesGoldenFile('overscroll_stretch.vertical.start.stretched.png'),
     );
 
     await gesture.up();
@@ -110,7 +110,11 @@ void main() {
 
     // Jump to end of the list
     controller.jumpTo(controller.position.maxScrollExtent);
+    await tester.pumpAndSettle();
     expect(controller.offset, 150.0);
+    expect(box1.localToGlobal(Offset.zero).dy, -150.0);
+    expect(box2.localToGlobal(Offset.zero).dy, 100.0);
+    expect(box3.localToGlobal(Offset.zero).dy, 350.0);
     await expectLater(
       find.byType(CustomScrollView),
       matchesGoldenFile('overscroll_stretch.vertical.end.png'),
@@ -125,8 +129,16 @@ void main() {
     expect(box3.localToGlobal(Offset.zero).dy, lessThan(350.0));
     await expectLater(
       find.byType(CustomScrollView),
-      matchesGoldenFile('overscroll_stretch.vertical.bottom.png'),
+      matchesGoldenFile('overscroll_stretch.vertical.end.stretched.png'),
     );
+
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    // Stretch released back
+    expect(box1.localToGlobal(Offset.zero).dy, -150.0);
+    expect(box2.localToGlobal(Offset.zero).dy, 100.0);
+    expect(box3.localToGlobal(Offset.zero).dy, 350.0);
   });
 
   testWidgets('Stretch overscroll works in reverse - vertical', (WidgetTester tester) async {
@@ -162,7 +174,7 @@ void main() {
     );
   });
 
-  testWidgets('Stretch overscroll horizontally', (WidgetTester tester) async {
+  testWidgets('Stretch overscroll works in reverse - horizontal', (WidgetTester tester) async {
     final Key box1Key = UniqueKey();
     final Key box2Key = UniqueKey();
     final Key box3Key = UniqueKey();
@@ -235,7 +247,7 @@ void main() {
     expect(box3.localToGlobal(Offset.zero).dx, greaterThan(610.0));
     await expectLater(
       find.byType(CustomScrollView),
-      matchesGoldenFile('overscroll_stretch.horizontal.left.png'),
+      matchesGoldenFile('overscroll_stretch.horizontal.start.stretched.png'),
     );
 
     await gesture.up();
@@ -248,7 +260,11 @@ void main() {
 
     // Jump to end of the list
     controller.jumpTo(controller.position.maxScrollExtent);
+    await tester.pumpAndSettle();
     expect(controller.offset, 100.0);
+    expect(box1.localToGlobal(Offset.zero).dx, -100.0);
+    expect(box2.localToGlobal(Offset.zero).dx, 200.0);
+    expect(box3.localToGlobal(Offset.zero).dx, 500.0);
     await expectLater(
       find.byType(CustomScrollView),
       matchesGoldenFile('overscroll_stretch.horizontal.end.png'),
@@ -263,8 +279,16 @@ void main() {
     expect(box3.localToGlobal(Offset.zero).dx, lessThan(500.0));
     await expectLater(
       find.byType(CustomScrollView),
-      matchesGoldenFile('overscroll_stretch.horizontal.right.png'),
+      matchesGoldenFile('overscroll_stretch.horizontal.end.stretched.png'),
     );
+
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    // Stretch released back
+    expect(box1.localToGlobal(Offset.zero).dx, -100.0);
+    expect(box2.localToGlobal(Offset.zero).dx, 200.0);
+    expect(box3.localToGlobal(Offset.zero).dx, 500.0);
   });
 
   testWidgets('Disallow stretching overscroll', (WidgetTester tester) async {