1 files changed, 57 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/nodes/Element-tagName.html b/testing/web-platform/tests/dom/nodes/Element-tagName.html
new file mode 100644
index 0000000000..43e7a2d2bf
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-tagName.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<title>Element.tagName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml"
+  assert_equals(document.createElementNS(HTMLNS, "I").tagName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "i").tagName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "x:b").tagName, "X:B")
+}, "tagName should upper-case for HTML elements in HTML documents.")
+
+test(function() {
+  var SVGNS = "http://www.w3.org/2000/svg"
+  assert_equals(document.createElementNS(SVGNS, "svg").tagName, "svg")
+  assert_equals(document.createElementNS(SVGNS, "SVG").tagName, "SVG")
+  assert_equals(document.createElementNS(SVGNS, "s:svg").tagName, "s:svg")
+  assert_equals(document.createElementNS(SVGNS, "s:SVG").tagName, "s:SVG")
+
+  assert_equals(document.createElementNS(SVGNS, "textPath").tagName, "textPath");
+}, "tagName should not upper-case for SVG elements in HTML documents.")
+
+test(() => {
+  const el2 = document.createElementNS("http://example.com/", "mixedCase");
+  assert_equals(el2.tagName, "mixedCase");
+}, "tagName should not upper-case for other non-HTML namespaces");
+
+test(function() {
+  if ("DOMParser" in window) {
+    var xmlel = new DOMParser()
+      .parseFromString('<div xmlns="http://www.w3.org/1999/xhtml">Test</div>', 'text/xml')
+      .documentElement;
+    assert_equals(xmlel.tagName, "div", "tagName should be lowercase in XML")
+    var htmlel = document.importNode(xmlel, true)
+    assert_equals(htmlel.tagName, "DIV", "tagName should be uppercase in HTML")
+  }
+}, "tagName should be updated when changing ownerDocument")
+
+test(function() {
+  var xmlel = document.implementation
+    .createDocument("http://www.w3.org/1999/xhtml", "div", null)
+    .documentElement;
+  assert_equals(xmlel.tagName, "div", "tagName should be lowercase in XML")
+  var htmlel = document.importNode(xmlel, true)
+  assert_equals(htmlel.tagName, "DIV", "tagName should be uppercase in HTML")
+}, "tagName should be updated when changing ownerDocument (createDocument without prefix)")
+
+test(function() {
+  var xmlel = document.implementation
+    .createDocument("http://www.w3.org/1999/xhtml", "foo:div", null)
+    .documentElement;
+  assert_equals(xmlel.tagName, "foo:div", "tagName should be lowercase in XML")
+  var htmlel = document.importNode(xmlel, true)
+  assert_equals(htmlel.tagName, "FOO:DIV", "tagName should be uppercase in HTML")
+}, "tagName should be updated when changing ownerDocument (createDocument with prefix)")
+</script>