feat: new Function - domContains

packages/dom/src/domContains.ts

@@ -0,0 +1,30 @@
+/**
+ * The function checks if a given node is contained within a root node, using either the native
+ * `contains` method or a fallback method for older browsers.
+ * @param {Node | null | undefined} root - The `root` parameter represents the root node of a tree or
+ * subtree.
+ * @param {Node | null} n - The parameter `n` represents a Node object that we want to check if it is
+ * contained within the `root` Node object.
+ * @returns a boolean value. It returns `true` if the `root` node contains the `n` node, and `false`
+ * otherwise.
+ * @linkcode https://github.com/GreatAuk/utopia-utils/blob/main/packages/dom/src/contains.ts
+ */
+export function domContains(root: Node | null | undefined, n: Node | null) {
+  if (!root)
+    return false
+
+  // Use native if support
+  if (root.contains)
+    return root.contains(n)
+
+  // `document.contains` not support with IE11
+  let node = n
+  while (node) {
+    if (node === root)
+      return true
+
+    node = node.parentNode
+  }
+
+  return false
+}