storybook/addons/knobs/src/components/__tests__/Select.js

import React from 'react';
import { shallow } from 'enzyme';
import SelectType from '../types/Select';

describe('Select', () => {
  let knob;

  describe('Object values', () => {
    beforeEach(() => {
      knob = {
        name: 'Colors',
        value: '#00ff00',
        options: {
          Green: '#00ff00',
          Red: '#ff0000',
        },
      };
    });

    describe('displays value', () => {
      it('correctly maps option keys and values', () => {
        const wrapper = shallow(<SelectType knob={knob} />);

        const green = wrapper.find('option').first();
        expect(green.text()).toEqual('Green');
        expect(green.prop('value')).toEqual('Green');
      });
    });
  });

  describe('Array values', () => {
    beforeEach(() => {
      knob = {
        name: 'Colors',
        value: 'green',
        options: ['green', 'red'],
      };
    });

    describe('displays value', () => {
      it('correctly maps option keys and values', () => {
        const wrapper = shallow(<SelectType knob={knob} />);

        const green = wrapper.find('option').first();
        expect(green.text()).toEqual('green');
        expect(green.prop('value')).toEqual('green');
      });
    });
  });
});