Refactoring Tests: Establish Format

test-setup.js

const setup = (propOverrides, renderFn = shallow) => {
  const props = {
    propA: 'Some Value',
    propB: false,
    onClick: jest.fn(),
    ...propOverrides,
  };

  const wrapper = renderFn(<AppComponent {...props} />);

  return { props, wrapper };
};