See the issue and the test case with original fix in https://github.com/facebook/react/pull/14802.

We'll need to fix it properly, see https://github.com/facebook/react/pull/14802#issuecomment-463277621.
}
    SomeComponent.contextTypes = {
      bar: PropTypes.string,
    };
    const shallowRenderer = createRenderer();
    const result = shallowRenderer.render(<SomeComponent foo={'FOO'} />, {
      bar: 'BAR',
    });
    expect(result.type).toBe('div');
    expect(result.props.children).toEqual([
      <div>FOO</div>,
      <div>BAR</div>,
      <span className="child1" />,
      <span className="child2" />,
    ]);
  });
  it('should shallow render a component returning strings directly from render', () => {
    const Text = ({value}) => value;
    const shallowRenderer = createRenderer();
    const result = shallowRenderer.render(<Text value="foo" />);
    expect(result).toEqual('foo');
  });
  it('should shallow render a component returning numbers directly from render', () => {
    const Text = ({value}) => value;
    const shallowRenderer = createRenderer();
    const result = shallowRenderer.render(<Text value={10} />);
    expect(result).toEqual(10);
  });
  it('should shallow render a fragment', () => {
    class SomeComponent extends React.Component {