From e0e1b09c7174cc8a78db812a5258b156b0a9dfff Mon Sep 17 00:00:00 2001
From: Tyler Jones <tyler@doublejones.com>
Date: Tue, 5 May 2020 18:07:20 -0700
Subject: [PATCH] portal: fix TypeError when using hot-loader (#574)

---
 packages/portal/src/index.tsx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/portal/src/index.tsx b/packages/portal/src/index.tsx
index fe2decced..447b2163f 100644
--- a/packages/portal/src/index.tsx
+++ b/packages/portal/src/index.tsx
@@ -26,6 +26,8 @@ const Portal: React.FC<PortalProps> = ({ children, type = "reach-portal" }) => {
   let [, forceUpdate] = useState();
 
   useIsomorphicLayoutEffect(() => {
+    // This ref may be null when a hot-loader replaces components on the page
+    if (!mountNode.current) return;
     // It's possible that the content of the portal has, itself, been portaled.
     // In that case, it's important to append to the correct document element.
     const ownerDocument = mountNode.current!.ownerDocument;