Import React when importing react-test-renderer in component tests

[erickakoyama]

It seems like React also needs to be imported in the test file for the TestRenderer to work. The setup I am using is:

"jest": "^23.4.1"
"react": "^16.8.2"
"react-test-renderer": "^16.8.3"

When running the jest unit tests I get the following error:

ReferenceError: React is not defined

Writing the import as the following seems to solve it for me:

import * as TestRenderer from 'react-test-renderer';
import React from 'react';

Also, for many test files that already contained a metal Component import, there is an import for React, but if it didn't have it explicitly before it seems to also need it.