Add missing Element::get_elements_by_* methods

Author: ia0

crates/web-sys/tests/wasm/element.rs

@@ -196,4 +196,29 @@ fn element() {
       request_fullscreen
       request_pointer_lock
     */
+
+    let child = new_div();
+    assert_eq!(
+        element.get_elements_by_tag_name("div").length(),
+        0,
+        "Element should not contain any div child"
+    );
+    element.append_child(&child).unwrap();
+    assert_eq!(
+        element.get_elements_by_tag_name("div").length(),
+        1,
+        "Element should contain one div child"
+    );
+    assert_eq!(
+        element.get_elements_by_class_name("foo").length(),
+        0,
+        "Element should not have childs with class foo"
+    );
+    child.class_list().add_1("foo").unwrap();
+    assert_eq!(
+        element.get_elements_by_class_name("foo").length(),
+        1,
+        "Element should have one child with class foo"
+    );
+    element.remove_child(&child).unwrap();
 }

crates/web-sys/webidls/enabled/Element.webidl

@@ -65,14 +65,12 @@ interface Element : Node {
   [Throws, Pure, BinaryName="matches"]
   boolean webkitMatchesSelector(DOMString selector);
 
-/*TODO
   [Pure]
   HTMLCollection getElementsByTagName(DOMString localName);
   [Throws, Pure]
   HTMLCollection getElementsByTagNameNS(DOMString? namespace, DOMString localName);
   [Pure]
   HTMLCollection getElementsByClassName(DOMString classNames);
-*/
   [ChromeOnly, Pure]
   sequence<Element> getElementsWithGrid();