anchor.diff:  
     int warningCount = 0;
     int errorCount = 0;
  +  int infoCount = 0;
     void handler(Uri uri, int begin, int end, String message, Diagnostic kind) {
       if (uri != null) {
         // print('$uri:$begin:$end: $kind: $message');
  
positive.code:         warningCount++;
        } else if (kind == Diagnostic.ERROR) {
          errorCount++;
        } else {
          throw kind;
        }
  
negative.code:   result.then((String code) {
      Expect.isNull(code);
      Expect.isTrue(10 < count);
      Expect.equals(0, warningCount);
      Expect.equals(1, errorCount);
      // Two infos for each time RECURSIVE_MAIN is read, except the
      // first time.
      Expect.equals(2 * (count - 1), infoCount);
    }, onError: (AsyncError e) {
        throw 'Compilation failed';
    });
  