app/components/Legend/__tests__/index-test.js
import React from 'react';
import renderer from 'react-test-renderer';
import Legend from '..';
// mock nested components
jest.mock('../LegendItem', () => 'div');
it('renders correctly', () => {
const mockData = [{ key: 1 }, { key: 2 }];
const tree = renderer
.create(<Legend data={mockData} dataValue="test" dataLabel="test" dataKey="key" color={() => {}} />)
.toJSON();
expect(tree).toMatchSnapshot();
});