text: import counter from '../../app/reducers/counter'
  import { INCREMENT_COUNTER, DECREMENT_COUNTER } from '../../app/actions/counter'
  
  describe('reducers', () => {
    describe('counter', () => {
      it('should handle initial state', () => {
        expect(counter(undefined, {})).toBe(0)
      })
  
      it('should handle INCREMENT_COUNTER', () => {
        expect(counter(1, { type: INCREMENT_COUNTER })).toBe(2)
      })
  
      it('should handle DECREMENT_COUNTER', () => {
        expect(counter(1, { type: DECREMENT_COUNTER })).toBe(0)
      })
  
      it('should handle unknown action type', () => {
        expect(counter(1, { type: 'unknown' })).toBe(1)
      })
    })
  })
  