ddcAdmin/node_modules/better-scroll/test/unit/specs/features/wheel.js

import BScroll from 'scroll/index'

describe('BScroll - wheel', () => {
  let wheels = []
  let wrapper = null
  beforeEach(() => {
    let style = document.createElement('style')
    style.type = 'text/css'
    const styleSheet = `
      ul {
        width: 100px;
        list-style: none;
        display: inline-block;
        margin: 0;
      }
      .wheel-wrapper {
        display: flex;
        overflow: hidden;
      }
      .wheel {
        flex: 1;
        height: 173px;
      }
      .wheel-scroll {
        padding: 0;
        margin-top: 68px;
        line-height: 36px;
        list-style: none;
      }
      .wheel-disabled-item {
        color: red
      }
    `
    style.appendChild(document.createTextNode(styleSheet))
    document.head.appendChild(style)

    wrapper = document.createElement('div')
    wrapper.className = 'wheel-wrapper'
    const listArr = []
    document.body.appendChild(wrapper)

    for (let i = 0; i < 3; i++) {
      let ulHTML = ''
      const ul = document.createElement('ul')
      ul.className = 'wheel-scroll'
      const scroller = document.createElement('div')
      scroller.className = 'wheel'
      for (let i = 0; i < 100; i++) {
        if (i === 0) {
          ulHTML += `<li class="wheel-item wheel-disabled-item">${i}</li>`
        } else {
          ulHTML += `<li class="wheel-item">${i}</li>`
        }
      }
      ul.innerHTML = ulHTML
      listArr.push(ul)
      scroller.appendChild(ul)
      wrapper.appendChild(scroller)
      wheels[i] = new BScroll(wrapper.children[i], {
        wheel: {
          selectedIndex: 0
        },
        probeType: 3
      })
    }
  })
  afterEach(() => {
    wheels = []
    wrapper = null
    document.body.removeChild(document.querySelector('.wheel-wrapper'))
  })
  it('the wheel wrapper class name should be use default value', () => {
    const wheel = wheels[0]
    expect(wheel.options.wheel.wheelWrapperClass).to.equal('wheel-scroll')
    expect(wheel.options.wheel.wheelItemClass).to.equal('wheel-item')
  })
  it('wheelTo', () => {
    const wheel = wheels[0]
    wheel.wheelTo(4)
    expect(wheel.getSelectedIndex())
      .to.equal(4)
    expect(wheel.y)
      .to.equal(-1 * wheel.itemHeight * 4)
  })
  it('getSelectedIndex', () => {
    const [firstWheel, secondWheel, thirdWheel] = [...wheels]
    expect(firstWheel.getSelectedIndex())
      .to.equal(1)
    expect(secondWheel.getSelectedIndex())
      .to.equal(1)
    expect(thirdWheel.getSelectedIndex())
      .to.equal(1)
  })
  it('will set selectedIndex to 0 when wheel.getSelectedIndex is undefined', () => {
    const firstWheel = new BScroll(wrapper.children[0], {
      wheel: {
        selectedIndex: undefined
      },
      probeType: 3
    })
    expect(firstWheel.options.startY).to.equal(0)
  })
  it('find nearest enable item', () => {
    const firstWheel = new BScroll(wrapper.children[0], {
      wheel: {
        selectedIndex: 0
      },
      probeType: 3
    })
    expect(firstWheel.selectedIndex).to.equal(1)
  })
})