From 858c6e8a1ca4065690a5087ec14bea204653c4e7 Mon Sep 17 00:00:00 2001
From: Tommie Gannert <tommie@gannert.se>
Date: Thu, 31 Oct 2024 19:19:57 +0100
Subject: [PATCH] Let CSSTransition use the transitionend event if there is no
 duration.

---
 src/CSSTransition.ts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/CSSTransition.ts b/src/CSSTransition.ts
index 0f6e290..f08ce48 100644
--- a/src/CSSTransition.ts
+++ b/src/CSSTransition.ts
@@ -51,6 +51,19 @@ const computeClassName = (phase: Phase, classNames: CSSTransitionClassNames) =>
 
 export default (props: CSSTransitionProps): VNode<any> => {
   const { children, classNames, ...rest } = props;
+
+  if (!rest.duration) {
+    const addEndListener = rest.addEndListener;
+
+    rest.addEndListener = (node: Element, done: () => void) => {
+      if (addEndListener) {
+        addEndListener(node, done);
+      } else {
+        node.addEventListener("transitionend", done, { once: true });
+      }
+    };
+  }
+
   return createElement(Transition, rest, (state, phase: Phase) => {
     const { className } = children.props;