diff --git a/tests/wpt/dom/nodes/Element-children.html b/tests/wpt/dom/nodes/Element-children.html
new file mode 100644
index 00000000..c0210f96
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-children.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<title>HTMLCollection edge cases</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="test"><img><img id=foo><img id=foo><img name="bar"></div>
+<script>
+setup(function() {
+  // Add some non-HTML elements in there to test what happens with those.
+  var container = document.getElementById("test");
+  var child = document.createElementNS("", "img");
+  child.setAttribute("id", "baz");
+  container.appendChild(child);
+
+  child = document.createElementNS("", "img");
+  child.setAttribute("name", "qux");
+  container.appendChild(child);
+});
+
+test(function() {
+  var container = document.getElementById("test");
+  var result = container.children.item("foo");
+  assert_true(result instanceof Element, "Expected an Element.");
+  assert_false(result.hasAttribute("id"), "Expected the IDless Element.")
+})
+
+test(function() {
+  var container = document.getElementById("test");
+  var list = container.children;
+  var result = [];
+  for (var p in list) {
+    if (list.hasOwnProperty(p)) {
+      result.push(p);
+    }
+  }
+  assert_array_equals(result, ['0', '1', '2', '3', '4', '5']);
+  result = Object.getOwnPropertyNames(list);
+  assert_array_equals(result, ['0', '1', '2', '3', '4', '5', 'foo', 'bar', 'baz']);
+
+  // Mapping of exposed names to their indices in the list.
+  var exposedNames = { 'foo': 1, 'bar': 3, 'baz': 4 };
+  for (var exposedName in exposedNames) {
+    assert_true(exposedName in list);
+    assert_true(list.hasOwnProperty(exposedName));
+    assert_equals(list[exposedName], list.namedItem(exposedName));
+    assert_equals(list[exposedName], list.item(exposedNames[exposedName]));
+    assert_true(list[exposedName] instanceof Element);
+  }
+
+  var unexposedNames = ['qux'];
+  for (var unexposedName of unexposedNames) {
+    assert_false(unexposedName in list);
+    assert_false(list.hasOwnProperty(unexposedName));
+    assert_equals(list[unexposedName], undefined);
+    assert_equals(list.namedItem(unexposedName), null);
+  }
+});
+</script>
diff --git a/tests/wpt/dom/nodes/Element-getElementsByClassName.html b/tests/wpt/dom/nodes/Element-getElementsByClassName.html
new file mode 100644
index 00000000..bc87b05d
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-getElementsByClassName.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<title>Element.getElementsByClassName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var a = document.createElement("a"), b = document.createElement("b")
+  b.className = "foo"
+  a.appendChild(b)
+  var list = a.getElementsByClassName("foo")
+  assert_array_equals(list, [b])
+  var secondList = a.getElementsByClassName("foo")
+  assert_true(list === secondList || list !== secondList, "Caching is allowed.")
+}, "getElementsByClassName should work on disconnected subtrees.")
+
+test(function() {
+  var list = document.getElementsByClassName("foo")
+  assert_false(list instanceof NodeList, "NodeList")
+  assert_true(list instanceof HTMLCollection, "HTMLCollection")
+}, "Interface should be correct.")
+
+test(function() {
+  var a = document.createElement("a");
+  var b = document.createElement("b");
+  var c = document.createElement("c");
+  b.className = "foo";
+  document.body.appendChild(a);
+  this.add_cleanup(function() {document.body.removeChild(a)});
+  a.appendChild(b);
+
+  var l = a.getElementsByClassName("foo");
+  assert_true(l instanceof HTMLCollection);
+  assert_equals(l.length, 1);
+
+  c.className = "foo";
+  a.appendChild(c);
+  assert_equals(l.length, 2);
+
+  a.removeChild(c);
+  assert_equals(l.length, 1);
+}, "getElementsByClassName() should be a live collection");
+</script>
diff --git a/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml b/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml
new file mode 100644
index 00000000..f3f286ea
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml
@@ -0,0 +1 @@
+<root/>
diff --git a/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html b/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html
new file mode 100644
index 00000000..c41ee2e8
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html
@@ -0,0 +1,51 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<iframe src="Element-getElementsByTagName-change-document-HTMLNess-iframe.xml"></iframe>
+<script>
+  setup({ single_test: true });
+  onload = function() {
+    var parent = document.createElement("div");
+    var child1 = document.createElementNS("http://www.w3.org/1999/xhtml", "a");
+    child1.textContent = "xhtml:a";
+    var child2 = document.createElementNS("http://www.w3.org/1999/xhtml", "A");
+    child2.textContent = "xhtml:A";
+    var child3 = document.createElementNS("", "a");
+    child3.textContent = "a";
+    var child4 = document.createElementNS("", "A");
+    child4.textContent = "A";
+
+    parent.appendChild(child1);
+    parent.appendChild(child2);
+    parent.appendChild(child3);
+    parent.appendChild(child4);
+
+    var list = parent.getElementsByTagName("A");
+    assert_array_equals(list, [child1, child4],
+      "In an HTML document, should lowercase the tagname passed in for HTML " +
+      "elements only");
+
+    frames[0].document.documentElement.appendChild(parent);
+    assert_array_equals(list, [child1, child4],
+      "After changing document, should still be lowercasing for HTML");
+
+    assert_array_equals(parent.getElementsByTagName("A"),
+                        [child2, child4],
+      "New list with same root and argument should not be lowercasing now");
+
+    // Now reinsert all those nodes into the parent, to blow away caches.
+    parent.appendChild(child1);
+    parent.appendChild(child2);
+    parent.appendChild(child3);
+    parent.appendChild(child4);
+    assert_array_equals(list, [child1, child4],
+      "After blowing away caches, should still have the same list");
+
+    assert_array_equals(parent.getElementsByTagName("A"),
+                        [child2, child4],
+      "New list with same root and argument should still not be lowercasing");
+    done();
+  }
+</script>
diff --git a/tests/wpt/dom/nodes/Element-getElementsByTagName.html b/tests/wpt/dom/nodes/Element-getElementsByTagName.html
new file mode 100644
index 00000000..87c4fe93
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-getElementsByTagName.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Element.getElementsByTagName</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagName.js"></script>
+<div id="log"></div>
+<script>
+var element;
+setup(function() {
+  element = document.createElement("div");
+  element.appendChild(document.createTextNode("text"));
+  var p = element.appendChild(document.createElement("p"));
+  p.appendChild(document.createElement("a"))
+   .appendChild(document.createTextNode("link"));
+  p.appendChild(document.createElement("b"))
+   .appendChild(document.createTextNode("bold"));
+  p.appendChild(document.createElement("em"))
+   .appendChild(document.createElement("u"))
+   .appendChild(document.createTextNode("emphasized"));
+  element.appendChild(document.createComment("comment"));
+});
+
+test_getElementsByTagName(element, element);
+
+test(function() {
+  assert_array_equals(element.getElementsByTagName(element.localName), []);
+}, "Matching the context object");
+</script>
diff --git a/tests/wpt/dom/nodes/Element-getElementsByTagNameNS.html b/tests/wpt/dom/nodes/Element-getElementsByTagNameNS.html
new file mode 100644
index 00000000..f826afc3
--- /dev/null
+++ b/tests/wpt/dom/nodes/Element-getElementsByTagNameNS.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Element.getElementsByTagNameNS</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagnamens">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagNameNS.js"></script>
+<div id="log"></div>
+<script>
+var element;
+setup(function() {
+  element = document.createElement("div");
+  element.appendChild(document.createTextNode("text"));
+  var p = element.appendChild(document.createElement("p"));
+  p.appendChild(document.createElement("a"))
+   .appendChild(document.createTextNode("link"));
+  p.appendChild(document.createElement("b"))
+   .appendChild(document.createTextNode("bold"));
+  p.appendChild(document.createElement("em"))
+   .appendChild(document.createElement("u"))
+   .appendChild(document.createTextNode("emphasized"));
+  element.appendChild(document.createComment("comment"));
+});
+
+test_getElementsByTagNameNS(element, element);
+
+test(function() {
+  assert_array_equals(element.getElementsByTagNameNS("*", element.localName), []);
+}, "Matching the context object (wildcard namespace)");
+
+test(function() {
+  assert_array_equals(
+    element.getElementsByTagNameNS("http://www.w3.org/1999/xhtml",
+                                   element.localName),
+    []);
+}, "Matching the context object (specific namespace)");
+</script>
