anchor.diff:    }
   
     CompilationUnit parseFile(List<String> relativeComponents) {
  -    List<String> pathComponents = rootComponents.toList()
  +    List<String> pathComponents = _analyzerRootComponents.toList()
         ..addAll(relativeComponents);
       String filePath = path.normalize(path.joinAll(pathComponents));
       return parseCompilationUnit(new File(filePath).readAsStringSync());
  
positive.code: 
  @reflectiveTest
  class ErrorCodeValuesTest extends ParserTestCase {
    List<String> _rootComponents;
  
    List<String> get rootComponents {
      if (_rootComponents == null) {
        List<String> components = path.split(package_root.packageRoot);
        components.add('analyzer');
        _rootComponents = components;
      }
      return _rootComponents;
    }
  
    bool bad() {
      return false;
    }
  
negative.code: import 'dart:io';
  
  import 'package:analyzer/dart/ast/ast.dart';
  import 'package:path/path.dart' as path;
  import 'package:test/test.dart';
  import 'package:test_reflective_loader/test_reflective_loader.dart';
  
  import '../generated/parser_test.dart';
  
  List<String> _analyzerRootComponents;
  
  main() {
    _analyzerRootComponents =
        path.split(path.fromUri(Platform.script.resolve("../../")));
    defineReflectiveSuite(() {
      defineReflectiveTests(ErrorCodeValuesTest);
    });
  