diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9e69d67f7..663fb9950 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -9,16 +9,19 @@ on:
   schedule:
     - cron: '0 0 * * *' # Every day at midnight
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   flutter-tests:
-    runs-on: ubuntu-latest
+    name: Test Flutter ${{ matrix.flutter_version }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        include:
-          - flutter_version: dev
-          - flutter_version: beta
-          - flutter_version: stable
+        flutter_version: [dev, beta, stable]
+        os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
@@ -27,11 +30,9 @@ jobs:
       - uses: subosito/flutter-action@v1
         with:
           channel: ${{ matrix.flutter_version }}
-      - run: ./tool/flutter_ci_script.sh
+      - run: ./tool/flutter_ci_script_${{ matrix.flutter_version }}.sh
   android-build:
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
@@ -43,8 +44,6 @@ jobs:
       - run: ./tool/android_ci_script.sh
   ios-build:
     runs-on: macos-latest
-    strategy:
-      fail-fast: false
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-java@v1
diff --git a/experimental/desktop_photo_search/lib/main.dart b/experimental/desktop_photo_search/lib/main.dart
index 203b64a65..db9921b51 100644
--- a/experimental/desktop_photo_search/lib/main.dart
+++ b/experimental/desktop_photo_search/lib/main.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:io';
-import 'dart:typed_data';
 
 import 'package:file_selector/file_selector.dart';
 import 'package:flutter/foundation.dart';
diff --git a/experimental/null_safety/null_safe_app/lib/badapp.dart b/experimental/null_safety/null_safe_app/lib/badapp.dart
index be5d20884..311a5b450 100644
--- a/experimental/null_safety/null_safe_app/lib/badapp.dart
+++ b/experimental/null_safety/null_safe_app/lib/badapp.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// ignore_for_file: unused_local_variable
+
 import 'package:flutter/material.dart';
 
 import 'services.dart';
diff --git a/experimental/null_safety/null_unsafe_app/test/widget_test.dart b/experimental/null_safety/null_unsafe_app/test/widget_test.dart
new file mode 100644
index 000000000..8c65b0917
--- /dev/null
+++ b/experimental/null_safety/null_unsafe_app/test/widget_test.dart
@@ -0,0 +1,15 @@
+// This is a basic Flutter widget test.
+//
+// To perform an interaction with a widget in your test, use the WidgetTester
+// utility that Flutter provides. For example, you can send tap and scroll
+// gestures. You can also use WidgetTester to find child widgets in the widget
+// tree, read text, and verify that the values of widget properties are correct.
+
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Rendering the page throws an exception',
+      (WidgetTester tester) async {
+    // Do nothing, running the app throws an exception on widget render.
+  });
+}
diff --git a/experimental/veggieseasons/lib/screens/settings.dart b/experimental/veggieseasons/lib/screens/settings.dart
index 6accd80d6..6f44fcbea 100644
--- a/experimental/veggieseasons/lib/screens/settings.dart
+++ b/experimental/veggieseasons/lib/screens/settings.dart
@@ -23,7 +23,8 @@ class VeggieCategorySettingsScreen extends StatelessWidget {
 
   static Route<void> _routeBuilder(BuildContext context, Object argument) {
     return CupertinoPageRoute(
-      builder: (context) => VeggieCategorySettingsScreen(restorationId: 'category'),
+      builder: (context) =>
+          VeggieCategorySettingsScreen(restorationId: 'category'),
       title: 'Preferred Categories',
     );
   }
@@ -136,9 +137,10 @@ class CalorieSettingsScreen extends StatelessWidget {
                       label: cals.toString(),
                       icon: SettingsIcon(
                         icon: Styles.checkIcon,
-                        foregroundColor: snapshot.hasData && snapshot.data == cals
-                            ? CupertinoColors.activeBlue
-                            : Styles.transparentColor,
+                        foregroundColor:
+                            snapshot.hasData && snapshot.data == cals
+                                ? CupertinoColors.activeBlue
+                                : Styles.transparentColor,
                         backgroundColor: Styles.transparentColor,
                       ),
                       onPress: snapshot.hasData
@@ -219,7 +221,8 @@ class SettingsScreen extends StatelessWidget {
       restorationId: restorationId,
       child: CupertinoPageScaffold(
         child: Container(
-          color: Styles.scaffoldBackground(CupertinoTheme.brightnessOf(context)),
+          color:
+              Styles.scaffoldBackground(CupertinoTheme.brightnessOf(context)),
           child: CustomScrollView(
             restorationId: 'list',
             slivers: <Widget>[
diff --git a/experimental/veggieseasons/test/restoration_test.dart b/experimental/veggieseasons/test/restoration_test.dart
index b06449ddd..4472f42ac 100644
--- a/experimental/veggieseasons/test/restoration_test.dart
+++ b/experimental/veggieseasons/test/restoration_test.dart
@@ -43,27 +43,32 @@ void main() {
     expect(find.text('Grapes'), findsNothing);
     expect(find.text('Figs'), findsOneWidget);
     expect(find.text('Serving info'), findsOneWidget);
-    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value, isFalse);
+    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value,
+        isFalse);
     await tester.tap(find.byType(CupertinoSwitch));
     await tester.pumpAndSettle();
-    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value, isTrue);
+    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value,
+        isTrue);
 
     // Current details page is restored.
     await tester.restartAndRestore();
     expect(find.text('Grapes'), findsNothing);
     expect(find.text('Figs'), findsOneWidget);
     expect(find.text('Serving info'), findsOneWidget);
-    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value, isTrue);
+    expect(tester.widget<CupertinoSwitch>(find.byType(CupertinoSwitch)).value,
+        isTrue);
 
     await tester.tap(find.text('Trivia'));
     await tester.pumpAndSettle();
     expect(find.text('Serving info'), findsNothing);
-    expect(find.text("Which of these isn't a variety of figs?"), findsOneWidget);
+    expect(
+        find.text("Which of these isn't a variety of figs?"), findsOneWidget);
 
     // Restores to trivia page.
     await tester.restartAndRestore();
     expect(find.text('Serving info'), findsNothing);
-    expect(find.text("Which of these isn't a variety of figs?"), findsOneWidget);
+    expect(
+        find.text("Which of these isn't a variety of figs?"), findsOneWidget);
 
     await tester.tap(find.text('Brown Turkey'));
     await tester.pumpAndSettle();
@@ -92,13 +97,15 @@ void main() {
     await tester.tap(find.text('My Garden'));
     await tester.pumpAndSettle();
 
-    expect(find.text('My Garden'), findsNWidgets(2)); // Name of the tap & title of page.
+    expect(find.text('My Garden'),
+        findsNWidgets(2)); // Name of the tap & title of page.
     expect(find.text('Grapes'), findsNothing);
     expect(find.text('Figs'), findsOneWidget);
 
     // Restores the current selected tab.
     await tester.restartAndRestore();
-    expect(find.text('My Garden'), findsNWidgets(2)); // Name of the tap & title of page.
+    expect(find.text('My Garden'),
+        findsNWidgets(2)); // Name of the tap & title of page.
     expect(find.text('Grapes'), findsNothing);
     expect(find.text('Figs'), findsOneWidget);
     expect(find.text('Apples'), findsNothing);
@@ -109,7 +116,8 @@ void main() {
 
     expect(find.text('Apples'), findsOneWidget);
     expect(find.text('Tangelo'), findsNothing);
-    await tester.enterText(find.byType(CupertinoTextField).hitTestable(), 'Tan');
+    await tester.enterText(
+        find.byType(CupertinoTextField).hitTestable(), 'Tan');
     await tester.pumpAndSettle();
     expect(find.text('Apples'), findsNothing);
     expect(find.text('Tangelo'), findsOneWidget);
@@ -129,7 +137,7 @@ void main() {
 
     expect(find.text('Tangelo'), findsOneWidget);
     expect(find.text('Serving info'), findsOneWidget);
-    
+
     // Restores details page
     await tester.restartAndRestore();
     expect(find.text('Tangelo'), findsOneWidget);
diff --git a/experimental/web_dashboard/lib/src/auth/firebase.dart b/experimental/web_dashboard/lib/src/auth/firebase.dart
index 5c8b7807a..99a308092 100644
--- a/experimental/web_dashboard/lib/src/auth/firebase.dart
+++ b/experimental/web_dashboard/lib/src/auth/firebase.dart
@@ -54,4 +54,3 @@ class _FirebaseUser implements User {
 
   _FirebaseUser(this.uid);
 }
-
diff --git a/experimental/web_dashboard/lib/src/auth/mock.dart b/experimental/web_dashboard/lib/src/auth/mock.dart
index a1bdcd16c..6dbf8ba46 100644
--- a/experimental/web_dashboard/lib/src/auth/mock.dart
+++ b/experimental/web_dashboard/lib/src/auth/mock.dart
@@ -13,7 +13,7 @@ class MockAuthService implements Auth {
   Future<User> signIn() async {
     // Sign in will randomly fail 25% of the time.
     var random = Random();
-    if (random.nextInt(4) == 0)  {
+    if (random.nextInt(4) == 0) {
       throw SignInException();
     }
     return MockUser();
diff --git a/experimental/web_dashboard/lib/src/pages/sign_in.dart b/experimental/web_dashboard/lib/src/pages/sign_in.dart
index 947db02d1..ca4cc9d92 100644
--- a/experimental/web_dashboard/lib/src/pages/sign_in.dart
+++ b/experimental/web_dashboard/lib/src/pages/sign_in.dart
@@ -95,7 +95,7 @@ class _SignInButtonState extends State<SignInButton> {
   }
 
   void _showError() {
-    Scaffold.of(context).showSnackBar(
+    ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(
         content: Text('Unable to sign in.'),
       ),
diff --git a/experimental/web_dashboard/tool/grind.dart b/experimental/web_dashboard/tool/grind.dart
index e98f791b8..88eace491 100644
--- a/experimental/web_dashboard/tool/grind.dart
+++ b/experimental/web_dashboard/tool/grind.dart
@@ -26,7 +26,8 @@ void runWeb() {
 @Task()
 void runFirebase() {
   run('flutter',
-      arguments: 'run -d web --web-port=5000 lib/main_firebase.dart '.split(' '));
+      arguments:
+          'run -d web --web-port=5000 lib/main_firebase.dart '.split(' '));
 }
 
 @Task()
diff --git a/tool/android_ci_script.sh b/tool/android_ci_script.sh
index f1b0f0b15..fcbb9e98a 100755
--- a/tool/android_ci_script.sh
+++ b/tool/android_ci_script.sh
@@ -21,7 +21,7 @@ declare -ar ANDROID_PROJECT_NAMES=(
 
 for PROJECT_NAME in "${ANDROID_PROJECT_NAMES[@]}"
 do
-    echo "== Testing '${PROJECT_NAME}' on Flutter's ${FLUTTER_VERSION} channel =="
+    echo "== Testing '${PROJECT_NAME}' on Flutter's stable channel =="
     pushd "${PROJECT_NAME}"
 
     ./gradlew --stacktrace assembleDebug
diff --git a/tool/flutter_ci_script_beta.sh b/tool/flutter_ci_script_beta.sh
new file mode 100755
index 000000000..23c91482c
--- /dev/null
+++ b/tool/flutter_ci_script_beta.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+
+set -e
+
+declare -ar PROJECT_NAMES=(
+    "add_to_app/flutter_module" \
+    "add_to_app/flutter_module_using_plugin" \
+    "add_to_app/flutter_module_books" \
+    "animations" \
+    # Tracking issue: https://github.com/flutter/samples/issues/652
+    # "flutter_maps_firestore" \
+    "infinite_list" \
+    "ios_app_clip" \
+    # Tracking issue: https://github.com/flutter/samples/issues/653
+    # "isolate_example" \
+    "jsonexample" \
+    # Tracking issue: https://github.com/flutter/samples/issues/655
+    # "place_tracker" \
+    # Tracking issue: https://github.com/flutter/samples/issues/656
+    # "platform_channels" \
+    "platform_design"
+    "platform_view_swift" \
+    "provider_counter" \
+    # Tracking issue: https://github.com/flutter/samples/issues/657
+    # "provider_shopper" \
+    # Tracking issue: https://github.com/flutter/samples/issues/658
+    # "testing_app" \
+    # Tracking issue: https://github.com/flutter/samples/issues/659
+    # "experimental/federated_plugin/federated_plugin" \
+    "experimental/null_safety/null_safe_app" \
+    "experimental/null_safety/null_unsafe_app" \
+    "experimental/veggieseasons" \
+    "experimental/web_dashboard" \
+)
+
+for PROJECT_NAME in "${PROJECT_NAMES[@]}"
+do
+    echo "== Testing '${PROJECT_NAME}' on Flutter's beta channel =="
+    pushd "${PROJECT_NAME}"
+
+    # Grab packages.
+    flutter pub get
+
+    # Run the analyzer to find any static analysis issues.
+    flutter analyze
+
+    # Reformat the web plugin registrant, if necessary.
+    if [ -f "lib/generated_plugin_registrant.dart" ]
+    then
+        echo "Renaming $(pwd)/lib/generated_plugin_registrant.dart"
+        flutter format "lib/generated_plugin_registrant.dart"
+    fi
+
+    # Run the formatter on all the dart files to make sure everything's linted.
+    flutter format -n --set-exit-if-changed .
+
+    # Run the actual tests.
+    flutter test
+
+    popd
+done
+
+echo "-- Success --"
diff --git a/tool/flutter_ci_script_dev.sh b/tool/flutter_ci_script_dev.sh
new file mode 100755
index 000000000..bbf8abc4d
--- /dev/null
+++ b/tool/flutter_ci_script_dev.sh
@@ -0,0 +1,64 @@
+#!/bin/bash
+
+set -e
+
+declare -ar PROJECT_NAMES=(
+    "add_to_app/flutter_module" \
+    "add_to_app/flutter_module_using_plugin" \
+    "add_to_app/flutter_module_books" \
+    "animations" \
+    # Tracking issue: https://github.com/flutter/samples/issues/652
+    # "flutter_maps_firestore" \
+    "infinite_list" \
+    "ios_app_clip" \
+    # Tracking issue: https://github.com/flutter/samples/issues/653
+    # "isolate_example" \
+    "jsonexample" \
+    # Tracking issue: https://github.com/flutter/samples/issues/655
+    # "place_tracker" \
+    # Tracking issue: https://github.com/flutter/samples/issues/656
+    # "platform_channels" \
+    "platform_design"
+    "platform_view_swift" \
+    "provider_counter" \
+    # Tracking issue: https://github.com/flutter/samples/issues/657
+    # "provider_shopper" \
+    # Tracking issue: https://github.com/flutter/samples/issues/658
+    # "testing_app" \
+    "experimental/desktop_photo_search" \
+    # https://github.com/flutter/samples/issues/659
+    # "experimental/federated_plugin/federated_plugin" \
+    "experimental/null_safety/null_safe_app" \
+    "experimental/null_safety/null_unsafe_app" \
+    "experimental/veggieseasons" \
+    "experimental/web_dashboard" \
+)
+
+for PROJECT_NAME in "${PROJECT_NAMES[@]}"
+do
+    echo "== Testing '${PROJECT_NAME}' on Flutter's dev channel =="
+    pushd "${PROJECT_NAME}"
+
+    # Grab packages.
+    flutter pub get
+
+    # Run the analyzer to find any static analysis issues.
+    flutter analyze
+
+    # Reformat the web plugin registrant, if necessary.
+    if [ -f "lib/generated_plugin_registrant.dart" ]
+    then
+        echo "Renaming $(pwd)/lib/generated_plugin_registrant.dart"
+        flutter format "lib/generated_plugin_registrant.dart"
+    fi
+
+    # Run the formatter on all the dart files to make sure everything's linted.
+    flutter format -n --set-exit-if-changed .
+
+    # Run the actual tests.
+    flutter test
+
+    popd
+done
+
+echo "-- Success --"
diff --git a/tool/flutter_ci_script.sh b/tool/flutter_ci_script_stable.sh
similarity index 93%
rename from tool/flutter_ci_script.sh
rename to tool/flutter_ci_script_stable.sh
index a0cb1b078..d9ccdb2cf 100755
--- a/tool/flutter_ci_script.sh
+++ b/tool/flutter_ci_script_stable.sh
@@ -25,7 +25,7 @@ declare -ar PROJECT_NAMES=(
 
 for PROJECT_NAME in "${PROJECT_NAMES[@]}"
 do
-    echo "== Testing '${PROJECT_NAME}' on Flutter's ${FLUTTER_VERSION} channel =="
+    echo "== Testing '${PROJECT_NAME}' on Flutter's stable channel =="
     pushd "${PROJECT_NAME}"
 
     # Grab packages.