anchor.diff:    }
   
     static int testTruncate() {
  -    String filename = getFilename("tests/vm/data/fixed_length_file");
  -    File file = new File("${filename}_out_truncate");
  +    File file = new File(tempDirectory.path + "/out_truncate");
       List buffer = const [65, 65, 65, 65, 65, 65, 65, 65, 65, 65];
       file.errorHandler = (error) {
         Expect.fail("testTruncate: No errors expected");
  
positive.code:         Expect.equals(42, bytes_read);
          file.closeHandler = () {
            // Write the contents of the file just read into another file.
            String outFilenameBase =
                getFilename("tests/vm/data/fixed_length_file");
            String outFilename = outFilenameBase + "_out_read_write";
            file = new File(outFilename);
            file.errorHandler = (s) {
              Expect.fail("No errors expected");
  
negative.code:                 file.deleteHandler = () {
                    file.existsHandler = (exists) {
                      Expect.isFalse(exists);
                      asyncTestDone();
                    };
                    file.exists();
                  };
  