[flutter_tools] remove mocks and fix fake imports (#81309)

packages/flutter_tools/lib/src/isolated/devfs_web.dart

@@ -74,9 +74,12 @@ const String _kDefaultIndex = '''
 ///
 /// This is only used in development mode.
 class WebExpressionCompiler implements ExpressionCompiler {
-  WebExpressionCompiler(this._generator);
+  WebExpressionCompiler(this._generator, {
+    @required FileSystem fileSystem,
+  }) : _fileSystem = fileSystem;
 
   final ResidentCompiler _generator;
+  final FileSystem _fileSystem;
 
   @override
   Future<ExpressionCompilationResult> compileExpressionToJs(
@@ -95,7 +98,7 @@ class WebExpressionCompiler implements ExpressionCompiler {
 
     if (compilerOutput != null && compilerOutput.outputFilename != null) {
       final String content = utf8.decode(
-          globals.fs.file(compilerOutput.outputFilename).readAsBytesSync());
+          _fileSystem.file(compilerOutput.outputFilename).readAsBytesSync());
       return ExpressionCompilationResult(
           content, compilerOutput.errorCount > 0);
     }

packages/flutter_tools/lib/src/isolated/resident_web_runner.dart

@@ -256,7 +256,7 @@ class ResidentWebRunner extends ResidentRunner {
       return await asyncGuard(() async {
         final ExpressionCompiler expressionCompiler =
           debuggingOptions.webEnableExpressionEvaluation
-              ? WebExpressionCompiler(device.generator)
+              ? WebExpressionCompiler(device.generator, fileSystem: _fileSystem)
               : null;
         device.devFS = WebDevFS(
           hostname: debuggingOptions.hostname ?? 'localhost',

packages/flutter_tools/test/general.shard/android/gradle_find_bundle_test.dart

@@ -11,7 +11,6 @@ import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/reporting/reporting.dart';
-import 'package:mockito/mockito.dart';
 
 import '../../src/common.dart';
 
@@ -32,7 +31,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barRelease', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barRelease/app.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores and uppercase letters in release mode', () {
@@ -45,7 +44,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barRelease', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barRelease/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores in release mode", () {
@@ -58,7 +57,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooRelease', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooRelease/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores but contains uppercase letters in release mode", () {
@@ -71,7 +70,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooaRelease', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooaRelease/app.aab');
   });
 
   testWithoutContext('Finds app bundle when no flavor is used in release mode', () {
@@ -84,7 +83,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'release', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/release/app.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores in debug mode', () {
@@ -97,7 +96,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barDebug', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barDebug/app.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores and uppercase letters in debug mode', () {
@@ -110,7 +109,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barDebug', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barDebug/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores in debug mode", () {
@@ -123,7 +122,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooDebug', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooDebug/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores but contains uppercase letters in debug mode", () {
@@ -136,7 +135,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooaDebug', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooaDebug/app.aab');
   });
 
   testWithoutContext('Finds app bundle when no flavor is used in debug mode', () {
@@ -149,7 +148,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'debug', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/debug/app.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores in profile mode', () {
@@ -162,7 +161,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barProfile', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barProfile/app.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores and uppercase letters in profile mode', () {
@@ -175,7 +174,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barProfile', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barProfile/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores in profile mode", () {
@@ -188,7 +187,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooProfile', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooProfile/app.aab');
   });
 
   testWithoutContext("Finds app bundle when flavor doesn't contain underscores but contains uppercase letters in profile mode", () {
@@ -201,7 +200,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'fooaProfile', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/fooaProfile/app.aab');
   });
 
   testWithoutContext('Finds app bundle when no flavor is used in profile mode', () {
@@ -214,7 +213,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'profile', 'app.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/profile/app.aab');
   });
 
   testWithoutContext('Finds app bundle in release mode - Gradle 3.5', () {
@@ -227,7 +226,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'release', 'app-release.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/release/app-release.aab');
   });
 
   testWithoutContext('Finds app bundle in profile mode - Gradle 3.5', () {
@@ -240,7 +239,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'profile', 'app-profile.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/profile/app-profile.aab');
   });
 
   testWithoutContext('Finds app bundle in debug mode - Gradle 3.5', () {
@@ -253,7 +252,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'debug', 'app-debug.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/debug/app-debug.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores in release mode - Gradle 3.5', () {
@@ -266,7 +265,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barRelease', 'app-foo_bar-release.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barRelease/app-foo_bar-release.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores and uppercase letters in release mode - Gradle 3.5', () {
@@ -279,7 +278,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barRelease', 'app-foo_bar-release.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barRelease/app-foo_bar-release.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores in profile mode - Gradle 3.5', () {
@@ -292,7 +291,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant', 'app', 'outputs', 'bundle', 'foo_barProfile', 'app-foo_bar-profile.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barProfile/app-foo_bar-profile.aab');
   });
 
   testWithoutContext('Finds app bundle when flavor contains underscores and uppercase letters in debug mode - Gradle 3.5', () {
@@ -305,7 +304,7 @@ void main() {
     );
 
     expect(bundle, isNotNull);
-    expect(bundle.path, fileSystem.path.join('irrelevant','app', 'outputs', 'bundle', 'foo_barDebug', 'app-foo_bar-debug.aab'));
+    expect(bundle.path, '/build/app/outputs/bundle/foo_barDebug/app-foo_bar-debug.aab');
   });
 
   testWithoutContext('AAB not found', () {
@@ -341,12 +340,7 @@ void main() {
 
 /// Generates a fake app bundle at the location [directoryName]/[fileName].
 FlutterProject generateFakeAppBundle(String directoryName, String fileName, FileSystem fileSystem) {
-  final FlutterProject project = MockFlutterProject();
-  final AndroidProject androidProject = MockAndroidProject();
-
-  when(project.isModule).thenReturn(false);
-  when(project.android).thenReturn(androidProject);
-  when(androidProject.buildDirectory).thenReturn(fileSystem.directory('irrelevant'));
+  final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
 
   final Directory bundleDirectory = getBundleDirectory(project);
   bundleDirectory
@@ -359,6 +353,3 @@ FlutterProject generateFakeAppBundle(String directoryName, String fileName, File
     .createSync();
   return project;
 }
-
-class MockAndroidProject extends Mock implements AndroidProject {}
-class MockFlutterProject extends Mock implements FlutterProject {}

packages/flutter_tools/test/general.shard/android/gradle_test.dart

@@ -19,11 +19,19 @@ import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/globals_null_migrated.dart' as globals;
 import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/reporting/reporting.dart';
-import 'package:mockito/mockito.dart';
+import 'package:test/fake.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
 
+const String kModulePubspec = '''
+name: test
+flutter:
+  module:
+    androidPackage: com.example
+    androidX: true
+''';
+
 void main() {
   Cache.flutterRoot = getFlutterRoot();
 
@@ -35,54 +43,42 @@ void main() {
     });
 
     testWithoutContext('getApkDirectory in app projects', () {
-      final FlutterProject project = MockFlutterProject();
-      final AndroidProject androidProject = MockAndroidProject();
-      when(project.android).thenReturn(androidProject);
-      when(project.isModule).thenReturn(false);
-      when(androidProject.buildDirectory).thenReturn(fileSystem.directory('foo'));
+      final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
 
       expect(
-        getApkDirectory(project).path,
-        equals(fileSystem.path.join('foo', 'app', 'outputs', 'flutter-apk')),
+        getApkDirectory(project).path, '/build/app/outputs/flutter-apk',
       );
     });
 
     testWithoutContext('getApkDirectory in module projects', () {
-      final FlutterProject project = MockFlutterProject();
-      final AndroidProject androidProject = MockAndroidProject();
-      when(project.android).thenReturn(androidProject);
-      when(project.isModule).thenReturn(true);
-      when(androidProject.buildDirectory).thenReturn(fileSystem.directory('foo'));
+      fileSystem.currentDirectory
+        .childFile('pubspec.yaml')
+        .writeAsStringSync(kModulePubspec);
+      final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
 
+      expect(project.isModule, true);
       expect(
-        getApkDirectory(project).path,
-        equals(fileSystem.path.join('foo', 'host', 'outputs', 'apk')),
+        getApkDirectory(project).path, '/build/host/outputs/apk',
       );
     });
 
     testWithoutContext('getBundleDirectory in app projects', () {
-      final FlutterProject project = MockFlutterProject();
-      final AndroidProject androidProject = MockAndroidProject();
-      when(project.android).thenReturn(androidProject);
-      when(project.isModule).thenReturn(false);
-      when(androidProject.buildDirectory).thenReturn(fileSystem.directory('foo'));
+      final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
 
       expect(
-        getBundleDirectory(project).path,
-        equals(fileSystem.path.join('foo', 'app', 'outputs', 'bundle')),
+        getBundleDirectory(project).path, '/build/app/outputs/bundle',
       );
     });
 
     testWithoutContext('getBundleDirectory in module projects', () {
-      final FlutterProject project = MockFlutterProject();
-      final AndroidProject androidProject = MockAndroidProject();
-      when(project.android).thenReturn(androidProject);
-      when(project.isModule).thenReturn(true);
-      when(androidProject.buildDirectory).thenReturn(fileSystem.directory('foo'));
+      fileSystem.currentDirectory
+        .childFile('pubspec.yaml')
+        .writeAsStringSync(kModulePubspec);
+      final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
 
+      expect(project.isModule, true);
       expect(
-        getBundleDirectory(project).path,
-        equals(fileSystem.path.join('foo', 'host', 'outputs', 'bundle')),
+        getBundleDirectory(project).path, '/build/host/outputs/bundle',
       );
     });
 
@@ -1028,5 +1024,3 @@ class FakeGradleUtils extends GradleUtils {
 }
 
 class FakeAndroidSdk extends Fake implements AndroidSdk {}
-class MockAndroidProject extends Mock implements AndroidProject {}
-class MockFlutterProject extends Mock implements FlutterProject {}

packages/flutter_tools/test/general.shard/device_port_forwarder_test.dart

@@ -4,9 +4,10 @@
 
 // @dart = 2.8
 
+import 'dart:io' as io; // ignore: dart_io_import
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/device_port_forwarder.dart';
-import 'package:mockito/mockito.dart';
+import 'package:test/fake.dart';
 
 import '../src/common.dart';
 import '../src/context.dart';
@@ -19,12 +20,20 @@ void main() {
   });
 
   testUsingContext('dispose kills process if process was available', () {
-    final MockProcess mockProcess = MockProcess();
-    final ForwardedPort forwardedPort = ForwardedPort.withContext(123, 456, mockProcess);
+    final FakeProcess process = FakeProcess();
+    final ForwardedPort forwardedPort = ForwardedPort.withContext(123, 456, process);
     forwardedPort.dispose();
+
     expect(forwardedPort.context, isNotNull);
-    verify(mockProcess.kill());
+    expect(process.killed, true);
   });
 }
 
-class MockProcess extends Mock implements Process {}
+class FakeProcess extends Fake implements Process {
+  bool killed = false;
+
+  @override
+  bool kill([io.ProcessSignal signal =  io.ProcessSignal.sigterm])  {
+    return killed = true;
+  }
+}

packages/flutter_tools/test/general.shard/flutter_validator_test.dart

@@ -12,7 +12,7 @@ import 'package:flutter_tools/src/base/user_messages.dart';
 import 'package:flutter_tools/src/doctor.dart';
 import 'package:flutter_tools/src/doctor_validator.dart';
 import 'package:flutter_tools/src/version.dart';
-import 'package:mockito/mockito.dart';
+import 'package:test/fake.dart';
 
 import '../src/common.dart';
 import '../src/fake_process_manager.dart';

packages/flutter_tools/test/general.shard/linux/linux_device_test.dart

@@ -14,7 +14,7 @@ import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/linux/application_package.dart';
 import 'package:flutter_tools/src/linux/linux_device.dart';
 import 'package:flutter_tools/src/project.dart';
-import 'package:mockito/mockito.dart';
+import 'package:test/fake.dart';
 
 import '../../src/common.dart';
 import '../../src/fake_process_manager.dart';
@@ -139,23 +139,17 @@ void main() {
   });
 
   testWithoutContext('LinuxDevice.executablePathForDevice uses the correct package executable', () async {
-    final MockLinuxApp mockApp = MockLinuxApp();
+    final FakeLinuxApp mockApp = FakeLinuxApp();
     final LinuxDevice device = LinuxDevice(
       logger: BufferLogger.test(),
       processManager: FakeProcessManager.any(),
       fileSystem: MemoryFileSystem.test(),
       operatingSystemUtils: FakeOperatingSystemUtils(),
     );
-    const String debugPath = 'debug/executable';
-    const String profilePath = 'profile/executable';
-    const String releasePath = 'release/executable';
-    when(mockApp.executable(BuildMode.debug)).thenReturn(debugPath);
-    when(mockApp.executable(BuildMode.profile)).thenReturn(profilePath);
-    when(mockApp.executable(BuildMode.release)).thenReturn(releasePath);
-
-    expect(device.executablePathForDevice(mockApp, BuildMode.debug), debugPath);
-    expect(device.executablePathForDevice(mockApp, BuildMode.profile), profilePath);
-    expect(device.executablePathForDevice(mockApp, BuildMode.release), releasePath);
+
+    expect(device.executablePathForDevice(mockApp, BuildMode.debug), 'debug/executable');
+    expect(device.executablePathForDevice(mockApp, BuildMode.profile), 'profile/executable');
+    expect(device.executablePathForDevice(mockApp, BuildMode.release), 'release/executable');
   });
 }
 
@@ -167,7 +161,21 @@ FlutterProject setUpFlutterProject(Directory directory) {
   return flutterProjectFactory.fromDirectory(directory);
 }
 
-class MockLinuxApp extends Mock implements LinuxApp {}
+class FakeLinuxApp extends Fake implements LinuxApp {
+  @override
+  String executable(BuildMode buildMode) {
+    switch (buildMode) {
+      case BuildMode.debug:
+        return 'debug/executable';
+      case BuildMode.profile:
+        return 'profile/executable';
+      case BuildMode.release:
+        return 'release/executable';
+      default:
+        throw StateError('Invalid mode: $buildMode');
+    }
+  }
+}
 class FakeOperatingSystemUtils extends Fake implements OperatingSystemUtils {
   FakeOperatingSystemUtils({
     HostPlatform hostPlatform = HostPlatform.linux_x64

packages/flutter_tools/test/general.shard/runner/runner_test.dart

@@ -19,7 +19,6 @@ import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:flutter_tools/src/reporting/crash_reporting.dart';
 import 'package:flutter_tools/src/reporting/reporting.dart';
 import 'package:flutter_tools/src/runner/flutter_command.dart';
-import 'package:mockito/mockito.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
@@ -180,9 +179,9 @@ void main() {
       expect(logContents, contains('String: an exception % --'));
       expect(logContents, contains('CrashingFlutterCommand.runCommand'));
       expect(logContents, contains('[✓] Flutter'));
+      print(globals.crashReporter.runtimeType);
 
-      final VerificationResult argVerification = verify(globals.crashReporter.informUser(captureAny, any));
-      final CrashDetails sentDetails = argVerification.captured.first as CrashDetails;
+      final CrashDetails sentDetails = (globals.crashReporter as WaitingCrashReporter)._details;
       expect(sentDetails.command, 'flutter crash');
       expect(sentDetails.error, 'an exception % --');
       expect(sentDetails.stackTrace.toString(), contains('CrashingFlutterCommand.runCommand'));
@@ -199,6 +198,7 @@ void main() {
       ProcessManager: () => FakeProcessManager.any(),
       UserMessages: () => CustomBugInstructions(),
       Artifacts: () => Artifacts.test(),
+      CrashReporter: () => WaitingCrashReporter(Future<void>.value())
     });
   });
 }
@@ -331,7 +331,11 @@ class WaitingCrashReporter implements CrashReporter {
   WaitingCrashReporter(Future<void> future) : _future = future;
 
   final Future<void> _future;
+  CrashDetails _details;
 
   @override
-  Future<void> informUser(CrashDetails details, File crashFile) => _future;
+  Future<void> informUser(CrashDetails details, File crashFile) {
+    _details = details;
+    return _future;
+  }
 }

packages/flutter_tools/test/general.shard/web/web_expression_compiler_test.dart

@@ -5,78 +5,55 @@
 // @dart = 2.8
 
 import 'package:dwds/dwds.dart';
+import 'package:file/memory.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/compile.dart';
-import 'package:flutter_tools/src/globals_null_migrated.dart' as globals;
 import 'package:flutter_tools/src/isolated/devfs_web.dart';
-import 'package:mockito/mockito.dart';
+import 'package:test/fake.dart';
 
 import '../../src/common.dart';
-import '../../src/testbed.dart';
 
 void main() {
-  Testbed testbed;
+  FileSystem fileSystem;
 
   setUp(() {
-    testbed = Testbed();
+    fileSystem = MemoryFileSystem.test();
   });
 
-  test('WebExpressionCompiler handles successful expression compilation', () => testbed.run(() async {
-    globals.fs.file('compilerOutput').writeAsStringSync('a');
-
-    final ResidentCompiler residentCompiler = MockResidentCompiler();
-    when(residentCompiler.compileExpressionToJs(
-      any, any, any, any, any, any, any
-    )).thenAnswer((Invocation invocation) async {
-      return const CompilerOutput('compilerOutput', 0, <Uri>[]);
-    });
-
-    final ExpressionCompiler expressionCompiler =
-      WebExpressionCompiler(residentCompiler);
+  testWithoutContext('WebExpressionCompiler handles successful expression compilation', () async {
+    fileSystem.file('compilerOutput').writeAsStringSync('a');
+    final ResidentCompiler residentCompiler = FakeResidentCompiler(const CompilerOutput('compilerOutput', 0, <Uri>[]));
+    final ExpressionCompiler expressionCompiler = WebExpressionCompiler(residentCompiler, fileSystem: fileSystem);
 
     final ExpressionCompilationResult result =
       await expressionCompiler.compileExpressionToJs(
         null, null, 1, 1, null, null, null, null);
 
     expectResult(result, false, 'a');
-  }));
-
-  test('WebExpressionCompiler handles compilation error', () => testbed.run(() async {
-    globals.fs.file('compilerOutput').writeAsStringSync('Error: a');
-
-    final ResidentCompiler residentCompiler = MockResidentCompiler();
-    when(residentCompiler.compileExpressionToJs(
-      any, any, any, any, any, any, any
-    )).thenAnswer((Invocation invocation) async {
-      return const CompilerOutput('compilerOutput', 1, <Uri>[]);
-    });
+  });
 
-    final ExpressionCompiler expressionCompiler =
-      WebExpressionCompiler(residentCompiler);
+  testWithoutContext('WebExpressionCompiler handles compilation error', () async {
+    fileSystem.file('compilerOutput').writeAsStringSync('Error: a');
+    final ResidentCompiler residentCompiler = FakeResidentCompiler(const CompilerOutput('compilerOutput', 1, <Uri>[]));
+    final ExpressionCompiler expressionCompiler = WebExpressionCompiler(residentCompiler, fileSystem: fileSystem);
 
     final ExpressionCompilationResult result =
       await expressionCompiler.compileExpressionToJs(
         null, null, 1, 1, null, null, null, null);
 
     expectResult(result, true, 'Error: a');
-  }));
-
-  test('WebExpressionCompiler handles internal error', () => testbed.run(() async {
-    final ResidentCompiler residentCompiler = MockResidentCompiler();
-    when(residentCompiler.compileExpressionToJs(
-      any, any, any, any, any, any, any
-    )).thenAnswer((Invocation invocation) async {
-      return null;
-    });
+  });
 
-    final ExpressionCompiler expressionCompiler =
-      WebExpressionCompiler(residentCompiler);
+  testWithoutContext('WebExpressionCompiler handles internal error', () async {
+    final ResidentCompiler residentCompiler = FakeResidentCompiler(null);
+    final ExpressionCompiler expressionCompiler = WebExpressionCompiler(residentCompiler, fileSystem: fileSystem);
 
     final ExpressionCompilationResult result =
       await expressionCompiler.compileExpressionToJs(
         null, null, 1, 1, null, null, null, 'a');
 
     expectResult(result, true, 'InternalError: frontend server failed to compile \'a\'');
-  }));
+  });
 }
 
 void expectResult(ExpressionCompilationResult result, bool isError, String value) {
@@ -86,4 +63,21 @@ void expectResult(ExpressionCompilationResult result, bool isError, String value
       .having((ExpressionCompilationResult instance) => instance.result, 'result', value));
 }
 
-class MockResidentCompiler extends Mock implements ResidentCompiler {}
+class FakeResidentCompiler extends Fake implements ResidentCompiler {
+  FakeResidentCompiler(this.output);
+
+  final CompilerOutput output;
+
+  @override
+  Future<CompilerOutput> compileExpressionToJs(
+    String libraryUri,
+    int line,
+    int column,
+    Map<String, String> jsModules,
+    Map<String, String> jsFrameValues,
+    String moduleName,
+    String expression,
+  ) async {
+    return output;
+  }
+}