text: import { changeBackground, defaultColor } from './backgroundColor';
  import { getCssLinearGradient } from '../colors';
  
  const validValue = { colors: [[0, 0, 0]] };
  const style = { backgroundImage: 'none' };
  
  beforeEach(() => {
    style.backgroundImage = 'none';
  });
  
  test('I return nothing!', () => {
    expect(changeBackground()).toBeUndefined();
  });
  
  test('valid input', () => {
    changeBackground(validValue, style);
    expect(style.backgroundImage).toBe(getCssLinearGradient(validValue.colors[0]));
  });
  
  test('incomplete input', () => {
    changeBackground(null, style);
    expect(style.backgroundImage).toBe(getCssLinearGradient(defaultColor));
  });
  
  test('wrong input', () => {
    changeBackground({ colors: [0] }, style);
    expect(style.backgroundImage).toBe(getCssLinearGradient(defaultColor));
  });
  
  test('no style', () => {
    changeBackground();
    expect(style.backgroundImage).toBe('none');
  });
  