chore: get rid of warnings when running react tests (#11821)

Author: SimenB

examples/react/.babelrc.js

@@ -2,12 +2,4 @@
 
 module.exports = {
   presets: ['@babel/preset-env', '@babel/preset-react'],
-  plugins: [
-    [
-      '@babel/plugin-proposal-class-properties',
-      {
-        loose: true,
-      },
-    ],
-  ],
 };

examples/react/package.json

@@ -8,7 +8,6 @@
   },
   "devDependencies": {
     "@babel/core": "*",
-    "@babel/plugin-proposal-class-properties": "*",
     "@babel/preset-env": "*",
     "@babel/preset-react": "*",
     "babel-jest": "*",

examples/snapshot/__tests__/link.react.test.js

@@ -33,13 +33,17 @@ it('changes the class when hovered', () => {
   expect(tree).toMatchSnapshot();
 
   // manually trigger the callback
-  tree.props.onMouseEnter();
+  renderer.act(() => {
+    tree.props.onMouseEnter();
+  });
   // re-rendering
   tree = component.toJSON();
   expect(tree).toMatchSnapshot();
 
   // manually trigger the callback
-  tree.props.onMouseLeave();
+  renderer.act(() => {
+    tree.props.onMouseLeave();
+  });
   // re-rendering
   tree = component.toJSON();
   expect(tree).toMatchSnapshot();