<!DOCTYPE html>
<meta charset=utf-8>
<title>Document.getElementById</title>
<link rel="author" title="Tetsuharu OHZEKI" href="mailto:saneyuki.snyk@gmail.com">
<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementbyid">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
  <div id="log"></div>

  <!-- test 0 -->
  <div id=""></div>

  <!-- test 1 -->
  <div id="test1"></div>

  <!-- test 5 -->
  <div id="test5" data-name="1st">
    <p id="test5" data-name="2nd">P</p>
    <input id="test5" type="submit" value="Submit" data-name="3rd">
  </div>

  <!-- test 15 -->
  <div id="outer">
    <div id="middle">
      <div id="inner"></div>
    </div>
  </div>

<script>
  var gBody = document.getElementsByTagName("body")[0];

  test(function() {
    assert_equals(document.getElementById(""), null);
  }, "Calling document.getElementById with an empty string argument.");

  test(function() {
    var element = document.createElement("div");
    element.setAttribute("id", "null");
    document.body.appendChild(element);
    this.add_cleanup(function() { document.body.removeChild(element) });
    assert_equals(document.getElementById(null), element);
  }, "Calling document.getElementById with a null argument.");

  test(function() {
    var element = document.createElement("div");
    element.setAttribute("id", "undefined");
    document.body.appendChild(element);
    this.add_cleanup(function() { document.body.removeChild(element) });
    assert_equals(document.getElementById(undefined), element);
  }, "Calling document.getElementById with an undefined argument.");


  test(function() {
    var bar = document.getElementById("test1");
    assert_not_equals(bar, null, "should not be null");
    assert_equals(bar.tagName, "DIV", "should have expected tag name.");
    assert_true(bar instanceof HTMLDivElement, "should be a valid Element instance");
  }, "on static page");


  test(function() {
    var TEST_ID = "test2";

    var test = document.createElement("div");
    test.setAttribute("id", TEST_ID);
    gBody.appendChild(test);

    // test: appended element
    var result = document.getElementById(TEST_ID);
    assert_not_equals(result, null, "should not be null.");
    assert_equals(result.tagName, "DIV", "should have appended element's tag name");
    assert_true(result instanceof HTMLDivElement, "should be a valid Element instance");

    // test: removed element
    gBody.removeChild(test);
    var removed = document.getElementById(TEST_ID);
    // `document.getElementById()` returns `null` if there is none.
    // https://dom.spec.whatwg.org/#dom-nonelementparentnode-getelementbyid
    assert_equals(removed, null, "should not get removed element.");
  }, "Document.getElementById with a script-inserted element");


  test(function() {
    // setup fixtures.
    var TEST_ID = "test3";
    var test = document.createElement("div");
    test.setAttribute("id", TEST_ID);
    gBody.appendChild(test);

    // update id
    var UPDATED_ID = "test3-updated";
    test.setAttribute("id", UPDATED_ID);
    var e = document.getElementById(UPDATED_ID);
    assert_equals(e, test, "should get the element with id.");

    var old = document.getElementById(TEST_ID);
    assert_equals(old, null, "shouldn't get the element by the old id.");

    // remove id.
    test.removeAttribute("id");
    var e2 = document.getElementById(UPDATED_ID);
    assert_equals(e2, null, "should return null when the passed id is none in document.");
  }, "update `id` attribute via setAttribute/removeAttribute");


  test(function() {
    var TEST_ID = "test4-should-not-exist";

    var e = document.createElement('div');
    e.setAttribute("id", TEST_ID);

    assert_equals(document.getElementById(TEST_ID), null, "should be null");
    document.body.appendChild(e);
    assert_equals(document.getElementById(TEST_ID), e, "should be the appended element");
  }, "Ensure that the id attribute only affects elements present in a document");


  test(function() {
    // the method should return the 1st element.
    var TEST_ID = "test5";
    var target = document.getElementById(TEST_ID);
    assert_not_equals(target, null, "should not be null");
    assert_equals(target.getAttribute("data-name"), "1st", "should return the 1st");

    // even if after the new element was appended.
    var element4 = document.createElement("div");
    element4.setAttribute("id", TEST_ID);
    element4.setAttribute("data-name", "4th");
    gBody.appendChild(element4);
    var target2 = document.getElementById(TEST_ID);
    assert_not_equals(target2, null, "should not be null");
    assert_equals(target2.getAttribute("data-name"), "1st", "should be the 1st");

    // should return the next element after removed the subtree including the 1st element.
    target2.parentNode.removeChild(target2);
    var target3 = document.getElementById(TEST_ID);
    assert_not_equals(target3, null, "should not be null");
    assert_equals(target3.getAttribute("data-name"), "4th", "should be the 4th");
  }, "in tree order, within the context object's tree");


  test(function() {
    var TEST_ID = "test6";
    var s = document.createElement("div");
    s.setAttribute("id", TEST_ID);
    // append to Element, not Document.
    document.createElement("div").appendChild(s);

    assert_equals(document.getElementById(TEST_ID), null, "should be null");
  }, "Modern browsers optimize this method with using internal id cache. " +
     "This test checks that their optimization should effect only append to `Document`, not append to `Node`.");


  test(function() {
    var TEST_ID = "test7"
    var element = document.createElement("div");
    element.setAttribute("id", TEST_ID);
    gBody.appendChild(element);

    var target = document.getElementById(TEST_ID);
    assert_equals(target, element, "should return the element before changing the value");

    element.attributes[0].value = TEST_ID + "-updated";
    var target2 = document.getElementById(TEST_ID);
    assert_equals(target2, null, "should return null after updated id via Attr.value");
    var target3 = document.getElementById(TEST_ID + "-updated");
    assert_equals(target3, element, "should be equal to the updated element.");
  }, "changing attribute's value via `Attr` gotten from `Element.attribute`.");


  test(function() {
    var TEST_ID = "test8";

    // setup fixture
    var element = document.createElement("div");
    element.setAttribute("id", TEST_ID + "-fixture");
    gBody.appendChild(element);

    // add id-ed element with using innerHTML
    element.innerHTML = "<div id='"+ TEST_ID +"'></div>";
    var test = document.getElementById(TEST_ID);
    assert_equals(test, element.firstChild, "should not be null");
    assert_equals(test.tagName, "DIV", "should have expected tag name.");
    assert_true(test instanceof HTMLDivElement, "should be a valid Element instance");
  }, "add id attribute via innerHTML");


  test(function() {
    var TEST_ID = "test9";

    // add fixture
    var fixture = document.createElement("div");
    fixture.setAttribute("id", TEST_ID + "-fixture");
    gBody.appendChild(fixture);

    var element = document.createElement("div");
    element.setAttribute("id", TEST_ID);
    fixture.appendChild(element);

    // check 'getElementById' should get the 'element'
    assert_equals(document.getElementById(TEST_ID), element, "should not be null");

    // remove id-ed element with using innerHTML (clear 'element')
    fixture.innerHTML = "";
    var test = document.getElementById(TEST_ID);
    assert_equals(test, null, "should be null.");
  }, "remove id attribute via innerHTML");


  test(function() {
    var TEST_ID = "test10";

    // setup fixture
    var element = document.createElement("div");
    element.setAttribute("id", TEST_ID + "-fixture");
    gBody.appendChild(element);

    // add id-ed element with using outerHTML
    element.outerHTML = "<div id='"+ TEST_ID +"'></div>";
    var test = document.getElementById(TEST_ID);
    assert_not_equals(test, null, "should not be null");
    assert_equals(test.tagName, "DIV", "should have expected tag name.");
    assert_true(test instanceof HTMLDivElement,"should be a valid Element instance");
  }, "add id attribute via outerHTML");


  test(function() {
    var TEST_ID = "test11";

    var element = document.createElement("div");
    element.setAttribute("id", TEST_ID);
    gBody.appendChild(element);

    var test = document.getElementById(TEST_ID);
    assert_equals(test, element, "should be equal to the appended element.");

    // remove id-ed element with using outerHTML
    element.outerHTML = "<div></div>";
    var test = document.getElementById(TEST_ID);
    assert_equals(test, null, "should be null.");
  }, "remove id attribute via outerHTML");


  test(function() {
    // setup fixtures.
    var TEST_ID = "test12";
    var test = document.createElement("div");
    test.id = TEST_ID;
    gBody.appendChild(test);

    // update id
    var UPDATED_ID = TEST_ID + "-updated";
    test.id =  UPDATED_ID;
    var e = document.getElementById(UPDATED_ID);
    assert_equals(e, test, "should get the element with id.");

    var old = document.getElementById(TEST_ID);
    assert_equals(old, null, "shouldn't get the element by the old id.");

    // remove id.
    test.id = "";
    var e2 = document.getElementById(UPDATED_ID);
    assert_equals(e2, null, "should return null when the passed id is none in document.");
  }, "update `id` attribute via element.id");


  test(function() {
    var TEST_ID = "test13";

    var create_same_id_element = function (order) {
      var element = document.createElement("div");
      element.setAttribute("id", TEST_ID);
      element.setAttribute("data-order", order);// for debug
      return element;
    };

    // create fixture
    var container = document.createElement("div");
    container.setAttribute("id", TEST_ID + "-fixture");
    gBody.appendChild(container);

    var element1 = create_same_id_element("1");
    var element2 = create_same_id_element("2");
    var element3 = create_same_id_element("3");
    var element4 = create_same_id_element("4");

    // append element: 2 -> 4 -> 3 -> 1
    container.appendChild(element2);
    container.appendChild(element4);
    container.insertBefore(element3, element4);
    container.insertBefore(element1, element2);


    var test = document.getElementById(TEST_ID);
    assert_equals(test, element1, "should return 1st element");
    container.removeChild(element1);

    test = document.getElementById(TEST_ID);
    assert_equals(test, element2, "should return 2nd element");
    container.removeChild(element2);

    test = document.getElementById(TEST_ID);
    assert_equals(test, element3, "should return 3rd element");
    container.removeChild(element3);

    test = document.getElementById(TEST_ID);
    assert_equals(test, element4, "should return 4th element");
    container.removeChild(element4);


  }, "where insertion order and tree order don't match");

  test(function() {
    var TEST_ID = "test14";
    var a = document.createElement("a");
    var b = document.createElement("b");
    a.appendChild(b);
    b.id = TEST_ID;
    assert_equals(document.getElementById(TEST_ID), null);

    gBody.appendChild(a);
    assert_equals(document.getElementById(TEST_ID), b);
  }, "Inserting an id by inserting its parent node");

  test(function () {
    var TEST_ID = "test15"
    var outer = document.getElementById("outer");
    var middle = document.getElementById("middle");
    var inner = document.getElementById("inner");
    outer.removeChild(middle);

    var new_el = document.createElement("h1");
    new_el.id = "heading";
    inner.appendChild(new_el);
    // the new element is not part of the document since
    // "middle" element was removed previously
    assert_equals(document.getElementById("heading"), null);
  }, "Document.getElementById must not return nodes not present in document");

  // TODO:
  // id attribute in a namespace


  // TODO:
  // SVG + MathML elements with id attributes

</script>
</body>
</html>