Add initial versions

closest.js

@@ -0,0 +1,16 @@
+export const closest = (node, selector, pierce) => {
+  const matches = node.matches || node.msMatchesSelector || node.oMatchesSelector;
+  while (node) {
+    if (matches.call(node, selector)) {
+      return node;
+    }
+    if (pierce && !node.parentElement) {
+      node = node.getRootNode();
+      if (node) {
+        node = node.host;
+      }
+    } else {
+      node = node.parentElement;
+    }
+  }
+};