From 140603456cbbdb7ffddd2f77d5232a18d405def9 Mon Sep 17 00:00:00 2001
From: Angus MacDonald <amacdonald@google.com>
Date: Thu, 3 Dec 2020 13:04:20 -0600
Subject: [PATCH] Add getMatchingParentElement()

---
 src/dom/get-matching-parent-element.ts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 src/dom/get-matching-parent-element.ts

diff --git a/src/dom/get-matching-parent-element.ts b/src/dom/get-matching-parent-element.ts
new file mode 100644
index 0000000000..d51d168d58
--- /dev/null
+++ b/src/dom/get-matching-parent-element.ts
@@ -0,0 +1,16 @@
+/**
+ * Returns a parent element of the given element that returns true for the
+ * given test function.
+ */
+export function getMatchingParentElement(
+    element: HTMLElement, testFunction: (element: HTMLElement) => boolean
+): HTMLElement {
+  let candidate = element.parentElement;
+  while (candidate) {
+    if (testFunction(candidate)) {
+      return candidate;
+    }
+    candidate = candidate.parentElement;
+  }
+  return undefined;
+}