text: import complement from '../complement';
  
  describe('utils/function/complement', () => {
      it('should return function opposite to passed', () => {
          const f = jest.fn(arg => arg);
          const g = complement(f);
  
          expect(g(true)).toBe(false);
          expect(f).toBeCalledWith(true);
  
          expect(g(0)).toBe(true);
          expect(f).toBeCalledWith(0);
      });
  });
  