[RootRef] Deprecate component

docs/pages/api-docs/root-ref.md

@@ -49,6 +49,8 @@ function MyComponent() {
 }
 ```
 
+@deprecated
+
 
 
 ## Props

package.json

@@ -33,13 +33,13 @@
     "size:why": "size-limit --why packages/material-ui/build/index.js",
     "start": "yarn docs:dev",
     "test": "yarn lint && yarn typescript && yarn test:coverage",
-    "test:coverage": "cross-env NODE_ENV=test BABEL_ENV=coverage nyc mocha 'packages/**/*.test.js' 'docs/**/*.test.js' --exclude '**/node_modules/**' && nyc report -r lcovonly",
-    "test:coverage:html": "cross-env NODE_ENV=test BABEL_ENV=coverage nyc mocha 'packages/**/**/*.test.js' --exclude '**/node_modules/**' && nyc report --reporter=html",
-    "test:karma": "cross-env NODE_ENV=test karma start test/karma.conf.js",
+    "test:coverage": "cross-env INTERNAL=true NODE_ENV=test BABEL_ENV=coverage nyc mocha 'packages/**/*.test.js' 'docs/**/*.test.js' --exclude '**/node_modules/**' && nyc report -r lcovonly",
+    "test:coverage:html": "cross-env INTERNAL=true NODE_ENV=test BABEL_ENV=coverage nyc mocha 'packages/**/**/*.test.js' --exclude '**/node_modules/**' && nyc report --reporter=html",
+    "test:karma": "cross-env INTERNAL=true NODE_ENV=test karma start test/karma.conf.js",
     "test:regressions": "yarn test:regressions:build && rimraf test/regressions/screenshots/chrome/* && vrtest run --config test/vrtest.config.js --record",
     "test:regressions:build": "webpack --config test/regressions/webpack.config.js",
     "test:umd": "node packages/material-ui/test/umd/run.js",
-    "test:unit": "cross-env NODE_ENV=test mocha 'packages/**/*.test.js' 'docs/**/*.test.js' 'scripts/**/*.test.js' --exclude '**/node_modules/**'",
+    "test:unit": "cross-env INTERNAL=true NODE_ENV=test mocha 'packages/**/*.test.js' 'docs/**/*.test.js' 'scripts/**/*.test.js' --exclude '**/node_modules/**'",
     "test:watch": "yarn test:unit --watch",
     "typescript": "lerna run --no-bail --parallel typescript"
   },

packages/material-ui/src/RootRef/RootRef.d.ts

@@ -36,6 +36,8 @@ export interface RootRefProps<T = any> {
  *   );
  * }
  * ```
+ *
+ * @deprecated
  * API:
  *
  * - [RootRef API](https://material-ui.com/api/root-ref/)

packages/material-ui/src/RootRef/RootRef.js

@@ -4,6 +4,8 @@ import PropTypes from 'prop-types';
 import { exactProp, refType } from '@material-ui/utils';
 import setRef from '../utils/setRef';
 
+let warnedOnce = false;
+
 /**
  * ⚠️⚠️⚠️
  * If you want the DOM element of a Material-UI component check out
@@ -35,6 +37,8 @@ import setRef from '../utils/setRef';
  *   );
  * }
  * ```
+ *
+ * @deprecated
  */
 class RootRef extends React.Component {
   componentDidMount() {
@@ -61,6 +65,19 @@ class RootRef extends React.Component {
   }
 
   render() {
+    if (process.env.NODE_ENV !== 'production') {
+      if (!warnedOnce && process.env.INTERNAL !== 'true') {
+        warnedOnce = true;
+        console.warn(
+          [
+            'Material-UI: The RootRef component is deprecated.',
+            'The component relies on the ReactDOM.findDOMNode API which is deprecated in React.StrictMode.',
+            'Instead, you can get a reference to the underlying DOM node of the components via the `ref` prop.',
+          ].join('/n'),
+        );
+      }
+    }
+
     return this.props.children;
   }
 }

test/karma.conf.js

@@ -55,6 +55,7 @@ module.exports = function setKarmaConfig(config) {
           'process.env': {
             NODE_ENV: JSON.stringify('test'),
             CI: JSON.stringify(process.env.CI),
+            INTERNAL: JSON.stringify(process.env.INTERNAL),
           },
         }),
       ],