From 3f163d29a47b2c16fe90618cac2a9d9c19e3765c Mon Sep 17 00:00:00 2001
From: Jenn Magder <magder@google.com>
Date: Wed, 3 Feb 2021 11:01:03 -0800
Subject: [PATCH] Return an empty FlutterViews list when the service disappears
 (#75301)

---
 packages/flutter_tools/lib/src/vmservice.dart                | 5 ++++-
 .../flutter_tools/test/general.shard/vmservice_test.dart     | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/flutter_tools/lib/src/vmservice.dart b/packages/flutter_tools/lib/src/vmservice.dart
index a0760316fb1..748f98b0581 100644
--- a/packages/flutter_tools/lib/src/vmservice.dart
+++ b/packages/flutter_tools/lib/src/vmservice.dart
@@ -779,7 +779,10 @@ extension FlutterVmService on vm_service.VmService {
         kListViewsMethod,
       );
       if (response == null) {
-        return null;
+        // The service may have disappeared mid-request.
+        // Return an empty list now, and let the shutdown logic elsewhere deal
+        // with cleaning up.
+        return <FlutterView>[];
       }
       final List<Object> rawViews = response.json['views'] as List<Object>;
       final List<FlutterView> views = <FlutterView>[
diff --git a/packages/flutter_tools/test/general.shard/vmservice_test.dart b/packages/flutter_tools/test/general.shard/vmservice_test.dart
index 4cf403c1a35..cdf51571659 100644
--- a/packages/flutter_tools/test/general.shard/vmservice_test.dart
+++ b/packages/flutter_tools/test/general.shard/vmservice_test.dart
@@ -356,7 +356,7 @@ void main() {
     expect(skSLs, isNull);
 
     final List<FlutterView> views = await fakeVmServiceHost.vmService.getFlutterViews();
-    expect(views, isNull);
+    expect(views, isEmpty);
 
     final vm_service.Response screenshot = await fakeVmServiceHost.vmService.screenshot();
     expect(screenshot, isNull);