")
    assert_equals(node.substringData(4, 1), "")
  }, type + ".substringData() with in-bounds offset")

  test(function() {
    var node = create()
    assert_equals(node.data, "test")

    assert_equals(node.substringData(0, 0), "")
    assert_equals(node.substringData(1, 0), "")
    assert_equals(node.substringData(2, 0), "")
    assert_equals(node.substringData(3, 0), "")
    assert_equals(node.substringData(4, 0), "")
  }, type + ".substringData() with zero count")

  test(function() {
    var node = 