diff --git a/testing_app/lib/screens/favorites.dart b/testing_app/lib/screens/favorites.dart
index 37ee345a689..cf63e27ea8a 100644
--- a/testing_app/lib/screens/favorites.dart
+++ b/testing_app/lib/screens/favorites.dart
@@ -55,7 +55,7 @@ class FavoriteItemTile extends StatelessWidget {
           icon: Icon(Icons.close),
           onPressed: () {
             Provider.of<Favorites>(context, listen: false).remove(itemNo);
-            Scaffold.of(context).showSnackBar(
+            ScaffoldMessenger.of(context).showSnackBar(
               SnackBar(
                 content: Text('Removed from favorites.'),
                 duration: Duration(seconds: 1),
diff --git a/testing_app/lib/screens/home.dart b/testing_app/lib/screens/home.dart
index e1fee87200c..56c4a6fda3f 100644
--- a/testing_app/lib/screens/home.dart
+++ b/testing_app/lib/screens/home.dart
@@ -67,7 +67,7 @@ class ItemTile extends StatelessWidget {
             !favoritesList.items.contains(itemNo)
                 ? favoritesList.add(itemNo)
                 : favoritesList.remove(itemNo);
-            Scaffold.of(context).showSnackBar(
+            ScaffoldMessenger.of(context).showSnackBar(
               SnackBar(
                 content: Text(favoritesList.items.contains(itemNo)
                     ? 'Added to favorites.'
diff --git a/testing_app/pubspec.lock b/testing_app/pubspec.lock
index 0bf7e6600e5..e87d96621cd 100644
--- a/testing_app/pubspec.lock
+++ b/testing_app/pubspec.lock
@@ -7,21 +7,21 @@ packages:
       name: _fe_analyzer_shared
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "12.0.0"
+    version: "14.0.0"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.40.6"
+    version: "0.41.2"
   archive:
     dependency: transitive
     description:
       name: archive
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.13"
+    version: "3.0.0-nullsafety.0"
   args:
     dependency: transitive
     description:
@@ -35,28 +35,28 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0-nullsafety.3"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0-nullsafety.5"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   cli_util:
     dependency: transitive
     description:
@@ -70,14 +70,14 @@ packages:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0-nullsafety.5"
   convert:
     dependency: transitive
     description:
@@ -91,14 +91,14 @@ packages:
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.2"
+    version: "0.15.1"
   crypto:
     dependency: transitive
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.5"
+    version: "3.0.0-nullsafety.0"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -119,14 +119,14 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   file:
     dependency: transitive
     description:
       name: file
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.0.0-nullsafety.2"
+    version: "6.0.0-nullsafety.4"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -154,13 +154,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.2.0"
-  http:
-    dependency: transitive
-    description:
-      name: http
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.12.2"
   http_multi_server:
     dependency: transitive
     description:
@@ -188,14 +181,7 @@ packages:
       name: js
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.6.3-nullsafety.2"
-  json_rpc_2:
-    dependency: transitive
-    description:
-      name: json_rpc_2
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.2.2"
+    version: "0.6.3-nullsafety.3"
   logging:
     dependency: transitive
     description:
@@ -209,14 +195,14 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10-nullsafety.3"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.6"
   mime:
     dependency: transitive
     description:
@@ -251,7 +237,7 @@ packages:
       name: node_preamble
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.12"
+    version: "1.4.13"
   package_config:
     dependency: transitive
     description:
@@ -265,42 +251,42 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0-nullsafety.3"
   pedantic:
     dependency: "direct dev"
     description:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.2"
+    version: "1.10.0-nullsafety.3"
   platform:
     dependency: transitive
     description:
       name: platform
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0-nullsafety.2"
+    version: "3.0.0-nullsafety.4"
   pool:
     dependency: transitive
     description:
       name: pool
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.0-nullsafety.2"
+    version: "1.5.0-nullsafety.3"
   process:
     dependency: transitive
     description:
       name: process
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.0.0-nullsafety.2"
+    version: "4.0.0-nullsafety.4"
   provider:
     dependency: "direct main"
     description:
       name: provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.3.2+3"
+    version: "4.3.3"
   pub_semver:
     dependency: transitive
     description:
@@ -321,21 +307,21 @@ packages:
       name: shelf_packages_handler
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.0.1"
   shelf_static:
     dependency: transitive
     description:
       name: shelf_static
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.9+1"
+    version: "0.2.9+2"
   shelf_web_socket:
     dependency: transitive
     description:
       name: shelf_web_socket
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.3"
+    version: "0.2.4"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -347,105 +333,98 @@ packages:
       name: source_map_stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0-nullsafety.4"
   source_maps:
     dependency: transitive
     description:
       name: source_maps
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.10.10-nullsafety.2"
+    version: "0.10.10-nullsafety.3"
   source_span:
     dependency: transitive
     description:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0-nullsafety.4"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0-nullsafety.6"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   sync_http:
     dependency: transitive
     description:
       name: sync_http
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.0"
+    version: "0.3.0-nullsafety.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   test:
     dependency: "direct dev"
     description:
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.16.0-nullsafety.5"
+    version: "1.16.0-nullsafety.17"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19-nullsafety.6"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.12-nullsafety.5"
+    version: "0.3.12-nullsafety.15"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.5"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0-nullsafety.5"
   vm_service:
     dependency: transitive
     description:
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.5.0"
-  vm_service_client:
-    dependency: transitive
-    description:
-      name: vm_service_client
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.2.6+2"
+    version: "6.0.1-nullsafety.0"
   watcher:
     dependency: transitive
     description:
@@ -459,14 +438,14 @@ packages:
       name: web_socket_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   webdriver:
     dependency: transitive
     description:
       name: webdriver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.2"
+    version: "3.0.0-nullsafety.1"
   webkit_inspection_protocol:
     dependency: transitive
     description:
@@ -482,5 +461,5 @@ packages:
     source: hosted
     version: "2.2.1"
 sdks:
-  dart: ">=2.10.0 <2.11.0"
-  flutter: ">=1.16.0 <2.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"
+  flutter: ">=1.16.0"