anchor.diff:          "show main;");
     }
     sb.writeln("\nvoid main() {");
  +  sb.writeln("  Directory.current = '${testRoot.resolve('..').toFilePath()}';");
     sb.writeln("  runTests(<String, Function> {");
     for (TestDescription description in unitTests) {
       String shortName = description.shortName.replaceAll("/", "__");
  
positive.code: import 'dart:isolate' show
      ReceivePort;
  
  import 'dart:async' show
      Future;
  
  import 'package:rasta/testing.dart' show
      TestDescription,
      dartArguments,
      dartSdk,
      listTests,
      startDart;
  
  main() async {
    final ReceivePort port = new ReceivePort();
    List<TestDescription> descriptions =
        await listTests(<Uri>[Platform.script.resolve(".")]).toList();
    descriptions.sort();
    List<TestDescription> unitTests = <TestDescription>[];
    List<TestDescription> goldenTests = <TestDescription>[];
  
negative.code:   }
    await analyzeTests(unitTests);
    StringBuffer sb = new StringBuffer();
    sb.writeln("library testing.combined;\n");
    sb.writeln("import 'dart:io' show Directory;\n");
    sb.writeln("import 'package:testing/src/run_tests.dart' show runTests;\n");
    for (TestDescription description in unitTests) {
      String shortName = description.shortName.replaceAll("/", "__");
      sb.writeln(
  