anchor.diff:  
     setUp(() {
       testLogger = BufferLogger.test();
  -    mockProcessManager = MockProcessManager();
  -    mockFrontendServer = MockProcess();
  +    processManager = FakeProcessManager();
       frontendServerStdIn = MemoryIOSink();
       fileSystem = MemoryFileSystem.test();
       generator = ResidentCompiler(
         'sdkroot',
         buildMode: BuildMode.debug,
         artifacts: Artifacts.test(),
  -      processManager: mockProcessManager,
  +      processManager: processManager,
         logger: testLogger,
         platform: FakePlatform(operatingSystem: 'linux'),
         fileSystem: fileSystem,
       );
   
       stdErrStreamController = StreamController<String>();
  -    when(mockFrontendServer.stdin).thenReturn(frontendServerStdIn);
  -    when(mockFrontendServer.stderr)
  -        .thenAnswer((Invocation invocation) => stdErrStreamController.stream.transform(utf8.encoder));
  -    when(mockFrontendServer.exitCode).thenAnswer((Invocation invocation) {
  -      return Completer<int>().future;
  -    });
  -
  -    when(mockProcessManager.canRun(any)).thenReturn(true);
  -    when(mockProcessManager.start(any)).thenAnswer(
  -            (Invocation invocation) =>
  -        Future<Process>.value(mockFrontendServer)
  -    );
  +    processManager.process.stdin = frontendServerStdIn;
  +    processManager.process.stderr = stdErrStreamController.stream.transform(utf8.encoder);
     });
   
     testWithoutContext('compile expression fails if not previously compiled', () async {
  
positive.code: import 'package:flutter_tools/src/build_info.dart';
  import 'package:flutter_tools/src/compile.dart';
  import 'package:flutter_tools/src/convert.dart';
  import 'package:mockito/mockito.dart';
  import 'package:package_config/package_config.dart';
  import 'package:process/process.dart';
  
  import '../src/common.dart';
  import '../src/fake_process_manager.dart';
  import '../src/fakes.dart';
  
  void main() {
    ProcessManager mockProcessManager;
    ResidentCompiler generator;
    MockProcess mockFrontendServer;
    MemoryIOSink frontendServerStdIn;
    StreamController<String> stdErrStreamController;
    BufferLogger testLogger;
  
negative.code:       ..createSync(recursive: true)
        ..writeAsBytesSync(<int>[1, 2, 3, 4]);
  
      processManager.process.stdout = Stream<List<int>>.fromFutures(
        <Future<List<int>>>[
          compileResponseCompleter.future,
          compileExpressionResponseCompleter.future]);
      compileResponseCompleter.complete(Future<List<int>>.value(utf8.encode(
        'result abc\nline1\nline2\nabc\nabc /path/to/main.dart.dill 0\n'
      )));
  