From 9312d1d8b0c20e226dc31d0878c9dfca75ed5737 Mon Sep 17 00:00:00 2001
From: Daniel Schmidt <dsc@charlietango.dk>
Date: Tue, 3 Nov 2020 10:31:13 +0100
Subject: [PATCH] fix: ensure undefined values are filtered from id

---
 src/observers.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/observers.ts b/src/observers.ts
index f38fe49f..2a297e2b 100644
--- a/src/observers.ts
+++ b/src/observers.ts
@@ -32,8 +32,8 @@ function getRootId(root?: Element | null) {
  */
 export function optionsToId(options: IntersectionObserverInit) {
   return Object.keys(options)
-    .filter(Boolean)
     .sort()
+    .filter((key) => options[key] !== undefined)
     .map((key) => {
       return `${key}_${
         key === 'root' ? getRootId(options.root) : options[key]