Warning: findDOMNode is deprecated in StrictMode when using react-bootstrap Navbar

Question

I tried to use react-bootstrap's Navbar component in the typescript template and I found below warning in Chrome console.

index.js:1 Warning: findDOMNode is deprecated in StrictMode. findDOMNode was passed an instance of Transition which is inside StrictMode. Instead, add a ref directly to the element you want to reference.
    in div (created by Context.Consumer)
    in Transition (created by Collapse)
    in Collapse (created by Context.Consumer)
    in NavbarCollapse (at NavigationBar.tsx:10)
    in nav (created by Navbar)
    in Navbar (at NavigationBar.tsx:7)
    in NavigationBar (at App.tsx:8)
    in div (at App.tsx:7)
    in App (at src/index.tsx:10)
    in StrictMode (at src/index.tsx:9)

Below is the code

import React from 'react';
import './NavigationBar.css';
import { Navbar, Nav, NavDropdown } from 'react-bootstrap';

function NavigationBar() {
    return (
        <Navbar bg="light" expand="lg">
            <Navbar.Brand href="#home">React-Bootstrap</Navbar.Brand>
            <Navbar.Toggle aria-controls="basic-navbar-nav" />
            <Navbar.Collapse id="basic-navbar-nav">
                <Nav className="mr-auto">
                    <Nav.Link href="#home">Home</Nav.Link>
                    <Nav.Link href="#link">Link</Nav.Link>
                    <NavDropdown title="Dropdown" id="basic-nav-dropdown">
                        <NavDropdown.Item href="#action/3.1">Action</NavDropdown.Item>
                        <NavDropdown.Item href="#action/3.2">Another action</NavDropdown.Item>
                        <NavDropdown.Item href="#action/3.3">Something</NavDropdown.Item>
                        <NavDropdown.Divider />
                        <NavDropdown.Item href="#action/3.4">Separated link</NavDropdown.Item>
                    </NavDropdown>
                </Nav>
            </Navbar.Collapse>
        </Navbar>);
}

export default NavigationBar;

Even the Navbar component's collapse function is working, what should I do to for warning message.

Answer 1

Apparently it's a github issue already. here

Since this is a warning (and not an error) therefore, your app will continue to work just fine. Facebook will eventually deprecate findDOMNode as it blocks certain improvements in React in the future

react-bootstrap will eventually upgrade it's code to drop using findDomNodes for other suitable alternatives.

Answer 2

Best solution for me was to set animation to false as suggested above however, you need to do it with animation="false" NOT animation={false} or you will get another warning. You will also need to add it to the Navbar.Collapse tag so:

<Navbar animation="false" ...>
  ...
  <Navbar.Collapse animation="false" ...>