diff --git a/analysis_options.yaml b/analysis_options.yaml
index ddd52e0f683a3..1fcc487181828 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml
@@ -16,6 +16,7 @@ analyzer:
     deprecated_member_use: ignore
     deprecated_member_use_from_same_package: ignore
   exclude: # DIFFERENT FROM FLUTTER/FLUTTER
+    - examples
     # Fixture depends on dart:ui and raises false positives.
     - flutter_frontend_server/test/fixtures/lib/main.dart
     - prebuilts
diff --git a/runtime/fixtures/dart_tool/flutter_build/dart_plugin_registrant.dart b/runtime/fixtures/dart_tool/flutter_build/dart_plugin_registrant.dart
index 11beca884b1ee..71075630145fc 100644
--- a/runtime/fixtures/dart_tool/flutter_build/dart_plugin_registrant.dart
+++ b/runtime/fixtures/dart_tool/flutter_build/dart_plugin_registrant.dart
@@ -4,7 +4,6 @@
 
 import 'dart:isolate';
 import 'dart:ui';
-import 'dart:io' show Platform;
 
 @pragma('vm:external-name', 'PassMessage')
 external void passMessage(String message);
@@ -14,18 +13,15 @@ bool didCallRegistrantBeforeEntrypoint = false;
 // Test the Dart plugin registrant.
 @pragma('vm:entry-point')
 class _PluginRegistrant {
-
   @pragma('vm:entry-point')
   static void register() {
     if (didCallRegistrantBeforeEntrypoint) {
-      throw '_registerPlugins is being called twice';
+      throw StateError('_registerPlugins is being called twice');
     }
     didCallRegistrantBeforeEntrypoint = true;
   }
-
 }
 
-
 @pragma('vm:entry-point')
 void mainForPluginRegistrantTest() {
   if (didCallRegistrantBeforeEntrypoint) {
@@ -42,22 +38,29 @@ void dartPluginRegistrantIsolate(SendPort sendPort) {
   sendPort.send(didCallRegistrantBeforeEntrypoint);
 }
 
-void registerBackgroundIsolate(List args) {
-  SendPort sendPort = args[0] as SendPort;
-  RootIsolateToken token = args[1] as RootIsolateToken;
+void registerBackgroundIsolate(List<Object?> args) {
+  final sendPort = args[0]! as SendPort;
+  final token = args[1]! as RootIsolateToken;
   PlatformDispatcher.instance.registerBackgroundIsolate(token);
   sendPort.send(didCallRegistrantBeforeEntrypoint);
 }
 
 @pragma('vm:entry-point')
-void callDartPluginRegistrantFromBackgroundIsolate() async {
-  ReceivePort receivePort = ReceivePort();
-  Isolate isolate = await Isolate.spawn(dartPluginRegistrantIsolate, receivePort.sendPort);
-  bool didCallEntrypoint = await receivePort.first;
+Future<void> callDartPluginRegistrantFromBackgroundIsolate() async {
+  final receivePort = ReceivePort();
+  final isolate = await Isolate.spawn(
+    dartPluginRegistrantIsolate,
+    receivePort.sendPort,
+  );
+  final didCallEntrypoint = await receivePort.first as bool;
   if (didCallEntrypoint) {
-    passMessage('_PluginRegistrant.register() was called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was called on background isolate',
+    );
   } else {
-    passMessage('_PluginRegistrant.register() was not called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was not called on background isolate',
+    );
   }
   isolate.kill();
 }
@@ -67,27 +70,41 @@ void noDartPluginRegistrantIsolate(SendPort sendPort) {
 }
 
 @pragma('vm:entry-point')
-void dontCallDartPluginRegistrantFromBackgroundIsolate() async {
-  ReceivePort receivePort = ReceivePort();
-  Isolate isolate = await Isolate.spawn(noDartPluginRegistrantIsolate, receivePort.sendPort);
-  bool didCallEntrypoint = await receivePort.first;
+Future<void> dontCallDartPluginRegistrantFromBackgroundIsolate() async {
+  final receivePort = ReceivePort();
+  final isolate = await Isolate.spawn(
+    noDartPluginRegistrantIsolate,
+    receivePort.sendPort,
+  );
+  final didCallEntrypoint = await receivePort.first as bool;
   if (didCallEntrypoint) {
-    passMessage('_PluginRegistrant.register() was called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was called on background isolate',
+    );
   } else {
-    passMessage('_PluginRegistrant.register() was not called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was not called on background isolate',
+    );
   }
   isolate.kill();
 }
 
 @pragma('vm:entry-point')
-void registerBackgroundIsolateCallsDartPluginRegistrant() async {
-  ReceivePort receivePort = ReceivePort();
-  Isolate isolate = await Isolate.spawn(registerBackgroundIsolate, [receivePort.sendPort, RootIsolateToken.instance]);
-  bool didCallEntrypoint = await receivePort.first;
+Future<void> registerBackgroundIsolateCallsDartPluginRegistrant() async {
+  final receivePort = ReceivePort();
+  final isolate = await Isolate.spawn(registerBackgroundIsolate, [
+    receivePort.sendPort,
+    RootIsolateToken.instance,
+  ]);
+  final didCallEntrypoint = await receivePort.first as bool;
   if (didCallEntrypoint) {
-    passMessage('_PluginRegistrant.register() was called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was called on background isolate',
+    );
   } else {
-    passMessage('_PluginRegistrant.register() was not called on background isolate');
+    passMessage(
+      '_PluginRegistrant.register() was not called on background isolate',
+    );
   }
   isolate.kill();
 }
diff --git a/runtime/fixtures/runtime_test.dart b/runtime/fixtures/runtime_test.dart
index 416902a815186..435c00430a1af 100644
--- a/runtime/fixtures/runtime_test.dart
+++ b/runtime/fixtures/runtime_test.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: avoid_print
+
 import 'dart:async';
 import 'dart:isolate';
-import 'dart:ui';
 
 import 'split_lib_test.dart' deferred as splitlib;
 
@@ -17,30 +18,28 @@ void sayHi() {
 
 @pragma('vm:entry-point')
 void throwExceptionNow() {
-  throw 'Hello';
+  throw AssertionError('Hello');
 }
 
 @pragma('vm:entry-point')
-void canRegisterNativeCallback() async {
+Future<void> canRegisterNativeCallback() async {
   print('In function canRegisterNativeCallback');
   notifyNative();
   print('Called native method from canRegisterNativeCallback');
 }
 
-Future<void>? splitLoadFuture = null;
+Future<void>? splitLoadFuture;
 
 @pragma('vm:entry-point')
 void canCallDeferredLibrary() {
   print('In function canCallDeferredLibrary');
-  splitLoadFuture = splitlib.loadLibrary()
-    .then((_) {
-        print('Deferred load complete');
-        notifySuccess(splitlib.splitAdd(10, 23) == 33);
-      })
-    .catchError((_) {
-        print('Deferred load error');
-        notifySuccess(false);
-      });
+  splitLoadFuture = splitlib.loadLibrary().then((_) {
+    print('Deferred load complete');
+    notifySuccess(splitlib.splitAdd(10, 23) == 33);
+  }).catchError((_) {
+    print('Deferred load error');
+    notifySuccess(false);
+  });
   notifyNative();
 }
 
@@ -48,7 +47,7 @@ void canCallDeferredLibrary() {
 external void notifyNative();
 
 @pragma('vm:entry-point')
-void testIsolateShutdown() {  }
+void testIsolateShutdown() {}
 
 @pragma('vm:external-name', 'NotifyNative')
 external void notifyResult(bool success);
@@ -56,44 +55,47 @@ external void notifyResult(bool success);
 external void passMessage(String message);
 
 void secondaryIsolateMain(String message) {
-  print('Secondary isolate got message: ' + message);
+  print('Secondary isolate got message: $message');
   passMessage('Hello from code is secondary isolate.');
   notifyNative();
 }
 
 @pragma('vm:entry-point')
 void testCanLaunchSecondaryIsolate() {
-  final onExit = RawReceivePort((_) { notifyNative(); });
-  Isolate.spawn(secondaryIsolateMain, 'Hello from root isolate.', onExit: onExit.sendPort);
+  final onExit = RawReceivePort((_) {
+    notifyNative();
+  });
+  Isolate.spawn(secondaryIsolateMain, 'Hello from root isolate.',
+      onExit: onExit.sendPort);
 }
 
-
 @pragma('vm:entry-point')
-void testIsolateStartupFailure() async {
-  Future mainTest(dynamic _) async {
-    Future testSuccessfullIsolateLaunch() async {
+Future<void> testIsolateStartupFailure() async {
+  Future<void> mainTest(void _) async {
+    Future<void> testSuccessfullIsolateLaunch() async {
       final onMessage = ReceivePort();
       final onExit = ReceivePort();
 
       final messages = StreamIterator<dynamic>(onMessage);
       final exits = StreamIterator<dynamic>(onExit);
 
-      await Isolate.spawn((SendPort port) => port.send('good'),
-          onMessage.sendPort, onExit: onExit.sendPort);
+      await Isolate.spawn(
+          (SendPort port) => port.send('good'), onMessage.sendPort,
+          onExit: onExit.sendPort);
       if (!await messages.moveNext()) {
-        throw 'Failed to receive message';
+        throw AssertionError('Failed to receive message');
       }
       if (messages.current != 'good') {
-        throw 'Failed to receive correct message';
+        throw AssertionError('Failed to receive correct message');
       }
       if (!await exits.moveNext()) {
-        throw 'Failed to receive onExit';
+        throw AssertionError('Failed to receive onExit');
       }
       messages.cancel();
       exits.cancel();
     }
 
-    Future testUnsuccessfullIsolateLaunch() async {
+    Future<void> testUnsuccessfullIsolateLaunch() async {
       IsolateSpawnException? error;
       try {
         await Isolate.spawn((_) {}, null);
@@ -101,7 +103,7 @@ void testIsolateStartupFailure() async {
         error = e;
       }
       if (error == null) {
-        throw 'Expected isolate spawn to fail.';
+        throw AssertionError('Expected isolate spawn to fail.');
       }
     }
 
@@ -115,6 +117,7 @@ void testIsolateStartupFailure() async {
   // test in an isolate.
   Isolate.spawn(mainTest, null);
 }
+
 @pragma('vm:external-name', 'MakeNextIsolateSpawnFail')
 external void makeNextIsolateSpawnFail();
 
@@ -132,35 +135,35 @@ void trampoline() {
 external void notifySuccess(bool success);
 
 @pragma('vm:entry-point')
-void testCanConvertEmptyList(List<int> args){
-  notifySuccess(args.length == 0);
+void testCanConvertEmptyList(List<int> args) {
+  notifySuccess(args.isEmpty);
 }
 
 @pragma('vm:entry-point')
-void testCanConvertListOfStrings(List<String> args){
+void testCanConvertListOfStrings(List<String> args) {
   notifySuccess(args.length == 4 &&
-                args[0] == 'tinker' &&
-                args[1] == 'tailor' &&
-                args[2] == 'soldier' &&
-                args[3] == 'sailor');
+      args[0] == 'tinker' &&
+      args[1] == 'tailor' &&
+      args[2] == 'soldier' &&
+      args[3] == 'sailor');
 }
 
 @pragma('vm:entry-point')
-void testCanConvertListOfDoubles(List<double> args){
+void testCanConvertListOfDoubles(List<double> args) {
   notifySuccess(args.length == 4 &&
-                args[0] == 1.0 &&
-                args[1] == 2.0 &&
-                args[2] == 3.0 &&
-                args[3] == 4.0);
+      args[0] == 1.0 &&
+      args[1] == 2.0 &&
+      args[2] == 3.0 &&
+      args[3] == 4.0);
 }
 
 @pragma('vm:entry-point')
-void testCanConvertListOfInts(List<int> args){
+void testCanConvertListOfInts(List<int> args) {
   notifySuccess(args.length == 4 &&
-                args[0] == 1 &&
-                args[1] == 2 &&
-                args[2] == 3 &&
-                args[3] == 4);
+      args[0] == 1 &&
+      args[1] == 2 &&
+      args[2] == 3 &&
+      args[3] == 4);
 }
 
 bool didCallRegistrantBeforeEntrypoint = false;
@@ -168,18 +171,15 @@ bool didCallRegistrantBeforeEntrypoint = false;
 // Test the Dart plugin registrant.
 @pragma('vm:entry-point')
 class _PluginRegistrant {
-
   @pragma('vm:entry-point')
   static void register() {
     if (didCallRegistrantBeforeEntrypoint) {
-      throw '_registerPlugins is being called twice';
+      throw AssertionError('_registerPlugins is being called twice');
     }
     didCallRegistrantBeforeEntrypoint = true;
   }
-
 }
 
-
 @pragma('vm:entry-point')
 void mainForPluginRegistrantTest() {
   if (didCallRegistrantBeforeEntrypoint) {
@@ -195,19 +195,19 @@ void mainForPlatformIsolates() {
 }
 
 @pragma('vm:entry-point')
-void emptyMain(args) {}
+void emptyMain(List<Object?> args) {}
 
 @pragma('vm:entry-point')
 Function createEntryPointForPlatIsoSendAndRecvTest() {
   final port = RawReceivePort();
-  port.handler = (message) {
+  port.handler = (Object? message) {
     port.close();
-    (message as SendPort).send('Hello from root isolate!');
+    (message! as SendPort).send('Hello from root isolate!');
   };
   final SendPort sendPort = port.sendPort;
   return () {
     final replyPort = RawReceivePort();
-    replyPort.handler = (message) {
+    replyPort.handler = (Object? message) {
       replyPort.close();
       passMessage('Platform isolate received: $message');
     };
@@ -217,5 +217,5 @@ Function createEntryPointForPlatIsoSendAndRecvTest() {
 
 @pragma('vm:entry-point')
 void mainForPlatformIsolatesThrowError() {
-  throw 'Error from platform isolate';
+  throw AssertionError('Error from platform isolate');
 }
diff --git a/shell/testing/observatory/launcher.dart b/shell/testing/observatory/launcher.dart
index 0b4e91e3a5140..ee734c87d7973 100644
--- a/shell/testing/observatory/launcher.dart
+++ b/shell/testing/observatory/launcher.dart
@@ -2,14 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: avoid_print
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 class ShellProcess {
-  final Completer<Uri> _vmServiceUriCompleter = Completer<Uri>();
-  final Process _process;
-
   ShellProcess(this._process) {
     // Scan stdout and scrape the VM Service Uri.
     _process.stdout
@@ -23,6 +22,9 @@ class ShellProcess {
     });
   }
 
+  final _vmServiceUriCompleter = Completer<Uri>();
+  final Process _process;
+
   Future<bool> kill() async {
     return _process.kill();
   }
@@ -44,6 +46,16 @@ class ShellProcess {
 }
 
 class ShellLauncher {
+  ShellLauncher(
+    this.shellExecutablePath,
+    this.mainDartPath,
+    this.startPaused,
+    List<String> extraArgs,
+  ) {
+    args.addAll(extraArgs);
+    args.add(mainDartPath);
+  }
+
   final List<String> args = <String>[
     '--vm-service-port=0',
     '--non-interactive',
@@ -54,12 +66,6 @@ class ShellLauncher {
   final String mainDartPath;
   final bool startPaused;
 
-  ShellLauncher(this.shellExecutablePath, this.mainDartPath, this.startPaused,
-      List<String> extraArgs) {
-    args.addAll(extraArgs);
-    args.add(mainDartPath);
-  }
-
   Future<ShellProcess?> launch() async {
     try {
       final List<String> shellArguments = <String>[];
@@ -68,8 +74,10 @@ class ShellLauncher {
       }
       shellArguments.addAll(args);
       print('Launching $shellExecutablePath $shellArguments');
-      final Process process =
-          await Process.start(shellExecutablePath, shellArguments);
+      final Process process = await Process.start(
+        shellExecutablePath,
+        shellArguments,
+      );
       return ShellProcess(process);
     } catch (e) {
       print('Error launching shell: $e');
diff --git a/shell/testing/observatory/service_client.dart b/shell/testing/observatory/service_client.dart
index 8d52c6ef1ca27..f9d74e31d4d0a 100644
--- a/shell/testing/observatory/service_client.dart
+++ b/shell/testing/observatory/service_client.dart
@@ -2,15 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: avoid_print
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 class ServiceClient {
-  Completer<dynamic>? isolateStartedId;
-  Completer<dynamic>? isolatePausedId;
-  Completer<dynamic>? isolateResumeId;
-
   ServiceClient(
     this.client, {
     this.isolateStartedId,
@@ -20,18 +18,23 @@ class ServiceClient {
     client.listen(_onData, onError: _onError, cancelOnError: true);
   }
 
-  Future<Map<String, dynamic>> invokeRPC(String method,
-      [Map<String, dynamic>? params]) async {
+  Completer<Object?>? isolateStartedId;
+  Completer<Object?>? isolatePausedId;
+  Completer<Object?>? isolateResumeId;
+
+  Future<Map<String, Object?>> invokeRPC(
+    String method, [
+    Map<String, Object?>? params,
+  ]) async {
     final String key = _createKey();
-    final String request = json.encode(<String, dynamic>{
+    final String request = json.encode({
       'jsonrpc': '2.0',
       'method': method,
-      'params': params == null ? <String, dynamic>{} : params,
+      'params': params ?? <String, Object?>{},
       'id': key,
     });
     client.add(request);
-    final Completer<Map<String, dynamic>> completer =
-        Completer<Map<String, dynamic>>();
+    final completer = Completer<Map<String, Object?>>();
     _outstandingRequests[key] = completer;
     print('-> $key ($method)');
     return completer.future;
@@ -44,55 +47,46 @@ class ServiceClient {
   }
 
   void _onData(dynamic message) {
-    final Map<String, dynamic> response =
-        json.decode(message as String) as Map<String, dynamic>;
+    final response = json.decode(message as String) as Map<String, Object?>;
     final dynamic key = response['id'];
     if (key != null) {
       print('<- $key');
-      final dynamic completer = _outstandingRequests.remove(key);
-      assert(completer != null);
-      final dynamic result = response['result'];
-      final dynamic error = response['error'];
+      final completer = _outstandingRequests.remove(key)!;
+      final result = response['result'];
+      final error = response['error'];
       if (error != null) {
-        assert(result == null);
         completer.completeError(error);
       } else {
-        assert(result != null);
         completer.complete(result);
       }
     } else {
       if (response['method'] == 'streamNotify') {
-        _onServiceEvent(response['params'] as Map<String, dynamic>?);
+        _onServiceEvent(response['params'] as Map<String, Object?>?);
       }
     }
   }
 
-  void _onServiceEvent(Map<String, dynamic>? params) {
+  void _onServiceEvent(Map<String, Object?>? params) {
     if (params == null) {
       return;
     }
-    final Map<String, dynamic>? event =
-        params['event'] as Map<String, dynamic>?;
+    final event = params['event'] as Map<String, Object?>?;
     if (event == null || event['type'] != 'Event') {
       return;
     }
-    final dynamic isolateId = event['isolate']['id'];
+    final dynamic isolateId = (event['isolate']! as Map<String, Object?>)['id'];
     switch (params['streamId']) {
       case 'Isolate':
         if (event['kind'] == 'IsolateStart') {
           isolateStartedId?.complete(isolateId);
         }
-        break;
       case 'Debug':
         switch (event['kind']) {
           case 'Resume':
             isolateResumeId?.complete(isolateId);
-            break;
           case 'PauseStart':
             isolatePausedId?.complete(isolateId);
-            break;
         }
-        break;
     }
   }
 
@@ -101,7 +95,6 @@ class ServiceClient {
   }
 
   final WebSocket client;
-  final Map<String, Completer<dynamic>> _outstandingRequests =
-      <String, Completer<dynamic>>{};
+  final _outstandingRequests = <String, Completer<dynamic>>{};
   int _id = 1;
 }
diff --git a/shell/testing/observatory/test.dart b/shell/testing/observatory/test.dart
index ad944dfb74210..2262769ff9880 100644
--- a/shell/testing/observatory/test.dart
+++ b/shell/testing/observatory/test.dart
@@ -4,6 +4,8 @@
 
 // This is a minimal dependency heart beat test for the Dart VM Service.
 
+// ignore_for_file: avoid_print
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -12,37 +14,9 @@ import 'launcher.dart';
 import 'service_client.dart';
 
 class Expect {
-  static void equals(dynamic actual, dynamic expected) {
+  static void equals(Object? actual, Object? expected) {
     if (actual != expected) {
-      throw 'Expected $actual == $expected';
-    }
-  }
-
-  static void contains(String needle, String haystack) {
-    if (!haystack.contains(needle)) {
-      throw 'Expected $haystack to contain $needle';
-    }
-  }
-
-  static void isTrue(bool tf) {
-    if (tf != true) {
-      throw 'Expected $tf to be true';
-    }
-  }
-
-  static void isFalse(bool tf) {
-    if (tf != false) {
-      throw 'Expected $tf to be false';
-    }
-  }
-
-  static void notExecuted() {
-    throw 'Should not have hit';
-  }
-
-  static void isNotNull(dynamic a) {
-    if (a == null) {
-      throw 'Expected $a to not be null';
+      throw AssertionError('Expected $actual == $expected');
     }
   }
 }
@@ -57,20 +31,20 @@ Future<String> readResponse(HttpClientResponse response) {
 }
 
 // Test accessing the service protocol over http.
-Future<Null> testHttpProtocolRequest(Uri uri) async {
+Future<void> testHttpProtocolRequest(Uri uri) async {
   uri = uri.replace(path: 'getVM');
   final HttpClient client = HttpClient();
   final HttpClientRequest request = await client.getUrl(uri);
   final HttpClientResponse response = await request.close();
   Expect.equals(response.statusCode, 200);
-  final Map<String, dynamic> responseAsMap =
-      json.decode(await readResponse(response)) as Map<String, dynamic>;
+  final responseAsMap =
+      json.decode(await readResponse(response)) as Map<String, Object?>;
   Expect.equals(responseAsMap['jsonrpc'], '2.0');
   client.close();
 }
 
 // Test accessing the service protocol over ws.
-Future<Null> testWebSocketProtocolRequest(Uri uri) async {
+Future<void> testWebSocketProtocolRequest(Uri uri) async {
   uri = uri.replace(scheme: 'ws', path: 'ws');
   final WebSocket webSocketClient = await WebSocket.connect(uri.toString());
   final ServiceClient serviceClient = ServiceClient(webSocketClient);
@@ -78,7 +52,7 @@ Future<Null> testWebSocketProtocolRequest(Uri uri) async {
   Expect.equals(response['type'], 'VM');
   try {
     await serviceClient.invokeRPC('BART_SIMPSON');
-    Expect.notExecuted();
+    throw AssertionError('Unreachable');
   } catch (e) {
     // Method not found.
     Expect.equals((e as Map<String, dynamic>)['code'], -32601);
@@ -86,73 +60,17 @@ Future<Null> testWebSocketProtocolRequest(Uri uri) async {
 }
 
 // Test accessing an Observatory UI asset.
-Future<Null> testHttpAssetRequest(Uri uri) async {
+Future<void> testHttpAssetRequest(Uri uri) async {
   uri = uri.replace(path: 'third_party/trace_viewer_full.html');
   final HttpClient client = HttpClient();
   final HttpClientRequest request = await client.getUrl(uri);
   final HttpClientResponse response = await request.close();
   Expect.equals(response.statusCode, 200);
-  await response.drain();
+  await response.drain<void>();
   client.close();
 }
 
-Future<Null> testStartPaused(Uri uri) async {
-  uri = uri.replace(scheme: 'ws', path: 'ws');
-  final WebSocket webSocketClient = await WebSocket.connect(uri.toString());
-  final Completer<dynamic> isolateStartedId = Completer<dynamic>();
-  final Completer<dynamic> isolatePausedId = Completer<dynamic>();
-  final Completer<dynamic> isolateResumeId = Completer<dynamic>();
-  final ServiceClient serviceClient = ServiceClient(webSocketClient,
-      isolateStartedId: isolateStartedId,
-      isolatePausedId: isolatePausedId,
-      isolateResumeId: isolateResumeId);
-  await serviceClient
-      .invokeRPC('streamListen', <String, String>{'streamId': 'Isolate'});
-  await serviceClient
-      .invokeRPC('streamListen', <String, String>{'streamId': 'Debug'});
-
-  final Map<String, dynamic> response = await serviceClient.invokeRPC('getVM');
-  Expect.equals(response['type'], 'VM');
-  String isolateId;
-  final List<dynamic> isolates = response['isolates'] as List<dynamic>;
-  if (isolates.isNotEmpty) {
-    isolateId = (isolates[0] as Map<String, String>)['id']!;
-  } else {
-    // Wait until isolate starts.
-    isolateId = await isolateStartedId.future as String;
-  }
-
-  // Grab the isolate.
-  Map<String, dynamic> isolate =
-      await serviceClient.invokeRPC('getIsolate', <String, String>{
-    'isolateId': isolateId,
-  });
-  Expect.equals(isolate['type'], 'Isolate');
-  Expect.isNotNull(isolate['pauseEvent']);
-  // If it is not runnable, wait until it becomes runnable.
-  if (isolate['pauseEvent']['kind'] == 'None') {
-    await isolatePausedId.future;
-    isolate = await serviceClient.invokeRPC('getIsolate', <String, String>{
-      'isolateId': isolateId,
-    });
-  }
-  // Verify that it is paused at start.
-  Expect.equals(isolate['pauseEvent']['kind'], 'PauseStart');
-
-  // Resume the isolate.
-  await serviceClient.invokeRPC('resume', <String, String>{
-    'isolateId': isolateId,
-  });
-  // Wait until the isolate has resumed.
-  await isolateResumeId.future;
-  final Map<String, dynamic> resumedResponse = await serviceClient
-      .invokeRPC('getIsolate', <String, String>{'isolateId': isolateId});
-  Expect.equals(resumedResponse['type'], 'Isolate');
-  Expect.isNotNull(resumedResponse['pauseEvent']);
-  Expect.equals(resumedResponse['pauseEvent']['kind'], 'Resume');
-}
-
-typedef TestFunction = Future<Null> Function(Uri uri);
+typedef TestFunction = Future<void> Function(Uri uri);
 
 final List<TestFunction> basicTests = <TestFunction>[
   testHttpProtocolRequest,
@@ -160,11 +78,6 @@ final List<TestFunction> basicTests = <TestFunction>[
   testHttpAssetRequest
 ];
 
-final List<TestFunction> startPausedTests = <TestFunction>[
-  // TODO(engine): Investigate difference in lifecycle events.
-  // testStartPaused,
-];
-
 Future<bool> runTests(ShellLauncher launcher, List<TestFunction> tests) async {
   final ShellProcess? process = await launcher.launch();
   if (process == null) {
@@ -184,7 +97,7 @@ Future<bool> runTests(ShellLauncher launcher, List<TestFunction> tests) async {
   return exitCode == 0;
 }
 
-Future<Null> main(List<String> args) async {
+Future<void> main(List<String> args) async {
   if (args.length < 2) {
     print('Usage: dart ${Platform.script} '
         '<sky_shell_executable> <main_dart> ...');
@@ -198,9 +111,5 @@ Future<Null> main(List<String> args) async {
   final ShellLauncher launcher =
       ShellLauncher(shellExecutablePath, mainDartPath, false, extraArgs);
 
-  final ShellLauncher startPausedlauncher =
-      ShellLauncher(shellExecutablePath, mainDartPath, true, extraArgs);
-
   await runTests(launcher, basicTests);
-  await runTests(startPausedlauncher, startPausedTests);
 }