anchor.diff:      var line = lines[0];
       Expect.isTrue(line.endsWith("42 bytes."));
       Expect.equals(42, line.length);
  -    name = getFilename("tests/standalone/src/readline_test1.dat");
  +    name = getDataFilename("tests/standalone/src/readline_test1.dat");
       lines = new File(name).readAsLinesSync();
       Expect.equals(10, lines.length);
     }
  
positive.code:   static String getFilename(String path) =>
        new File(path).existsSync() ? path : 'runtime/' + path;
  
    // Main test entrypoint.
    static testMain() {
      testRead();
  
negative.code:     var text = new File(name).readAsTextSync();
      Expect.isTrue(text.endsWith("42 bytes."));
      Expect.equals(42, text.length);
      name = getDataFilename("tests/standalone/src/read_as_text.dat");
      text = new File(name).readAsTextSync();
      Expect.equals(6, text.length);
      var expected = [955, 120, 46, 32, 120, 10];
  