From 13b42bcfd8673e3af44c70713cd82ca3ee41b553 Mon Sep 17 00:00:00 2001
From: Sebastian Silbermann <silbermann.sebastian@gmail.com>
Date: Thu, 31 Jan 2019 15:03:11 +0100
Subject: [PATCH] [react-dom] Allow maybe instance in findDOMNode

---
 types/react-dom/index.d.ts             | 2 +-
 types/react-dom/react-dom-tests.tsx    | 2 ++
 types/react-dom/v15/index.d.ts         | 2 +-
 types/react-dom/v15/react-dom-tests.ts | 2 ++
 4 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/types/react-dom/index.d.ts b/types/react-dom/index.d.ts
index f81bbf4021..19c842f5a2 100644
--- a/types/react-dom/index.d.ts
+++ b/types/react-dom/index.d.ts
@@ -17,7 +17,7 @@ import {
     DOMAttributes, DOMElement, ReactNode, ReactPortal
 } from 'react';
 
-export function findDOMNode(instance: ReactInstance): Element | null | Text;
+export function findDOMNode(instance: ReactInstance | null | undefined): Element | null | Text;
 export function unmountComponentAtNode(container: Element): boolean;
 
 export function createPortal(children: ReactNode, container: Element, key?: null | string): ReactPortal;
diff --git a/types/react-dom/react-dom-tests.tsx b/types/react-dom/react-dom-tests.tsx
index 46274e3ffd..20bfda53ea 100644
--- a/types/react-dom/react-dom-tests.tsx
+++ b/types/react-dom/react-dom-tests.tsx
@@ -30,6 +30,8 @@ describe('ReactDOM', () => {
         const rootElement = document.createElement('div');
         ReactDOM.render(React.createElement('div'), rootElement);
         ReactDOM.findDOMNode(rootElement);
+        ReactDOM.findDOMNode(null);
+        ReactDOM.findDOMNode(undefined);
     });
 
     it('createPortal', () => {
diff --git a/types/react-dom/v15/index.d.ts b/types/react-dom/v15/index.d.ts
index 8a22fd9bc2..653469b277 100644
--- a/types/react-dom/v15/index.d.ts
+++ b/types/react-dom/v15/index.d.ts
@@ -15,7 +15,7 @@ import {
     DOMAttributes, DOMElement
 } from 'react';
 
-export function findDOMNode<E extends Element>(instance: ReactInstance): E;
+export function findDOMNode<E extends Element>(instance: ReactInstance | null | undefined): E;
 export function findDOMNode(instance: ReactInstance): Element;
 
 export function render<P extends DOMAttributes<T>, T extends Element>(
diff --git a/types/react-dom/v15/react-dom-tests.ts b/types/react-dom/v15/react-dom-tests.ts
index 865d74e386..5f5b149594 100644
--- a/types/react-dom/v15/react-dom-tests.ts
+++ b/types/react-dom/v15/react-dom-tests.ts
@@ -25,6 +25,8 @@ describe('ReactDOM', () => {
         const rootElement = document.createElement('div');
         ReactDOM.render(React.createElement('div'), rootElement);
         ReactDOM.findDOMNode(rootElement);
+        ReactDOM.findDOMNode(null);
+        ReactDOM.findDOMNode(undefined);
     });
 });