text: import leftHorizontal from 'ui/routes/interpolators/leftHorizontal'
  
  const interpolateMock = jest.fn()
  const baseProps = {
    layout: {
      initWidth: 200
    },
    position: {
      interpolate: interpolateMock
    },
    scene: {
      index: 0
    },
    navigationState: {
      index: 0
    }
  }
  
  describe('leftHorizontal interpolator tests', () => {
    it('should return a default scene interpolator when the layout is not measured', () => {
      const interpolator = leftHorizontal.scene(baseProps)
      expect(interpolator).not.toBeNull()
      expect(interpolator.opacity).toEqual(1)
      expect(interpolator.transform.length).toEqual(2)
      expect(interpolateMock).not.toHaveBeenCalled()
    })
  
    it('should return scene interpolator when the layout has been measured and call interpolate where required', () => {
      const props = {
        ...baseProps,
        layout: {
          ...baseProps.layout,
          isMeasured: true
        }
      }
  
      const interpolator = leftHorizontal.scene(props)
      expect(interpolator).not.toBeNull()
      expect(interpolator.opacity).not.toBeNull()
      expect(interpolator.transform).not.toBeNull()
      expect(interpolator.transform.length).toBe(3)
      expect(interpolateMock).toHaveBeenCalledTimes(3)
      interpolateMock.mockClear()
    })
  
    it('should return header intrepolator', () => {
      const props = {
        ...baseProps,
        layout: {
          ...baseProps.layout,
          isMeasured: true
        }
      }
  
      const interpolator = leftHorizontal.header(props)
      expect(interpolator).not.toBeNull()
      expect(interpolator.opacity).not.toBeNull()
      expect(interpolator.transform).not.toBeNull()
      expect(interpolator.transform.length).toBe(1)
      expect(interpolateMock).toHaveBeenCalledTimes(2)
      interpolateMock.mockClear()
    })
  })
  