text: import reverse from '../../build/index'
  
  describe('number reverse', () => {
    test('reverse a number without specifying options', () => {
      const number = 12345
      expect(reverse(number)).toEqual(54321)
      expect(reverse(number)).not.toBeUndefined()
    })
  
    test('reverse a negative number without specifying options', () => {
      const number = -12345
      expect(reverse(number)).toEqual(-54321)
      expect(reverse(number)).not.toBeUndefined()
    })
  
    test('change the indexes of a positive number', () => {
      const number = 54321
      expect(reverse(number, {invert: 'index'}))
        .toEqual(12345)
    })
  
    test('change the indexes of a negative number', () => {
      const number = -54321
      expect(reverse(number, {invert: 'index'}))
        .toEqual(-12345)
    })
  
    test('turn a positive number to negative', () => {
      const number = 1234
      expect(reverse(number, {invert: 'sign'}))
        .toEqual(-1234)
    })
  
    test('turn a negative number to positive', () => {
      const number = -1234
      const reversed = reverse(number, {invert: 'sign'})
      expect(reversed).toEqual(1234)
    })
  })
  