Install `eslint-plugin-custom-elements`

$ npm install --save @github/task-lists-element

import '@github/task-lists-element'

<script type="module" src="./node_modules/@github/task-lists-element/dist/task-lists-element.js">

<task-lists sortable>
  <ul class="contains-task-list">
    <li class="task-list-item">
      <input type="checkbox" class="task-list-item-checkbox">
      Hubot
    </li>
    <li class="task-list-item">
      <input type="checkbox" class="task-list-item-checkbox">
      Bender
    </li>
  </ul>

  <ul class="contains-task-list">
    <li class="task-list-item">
      <input type="checkbox" class="task-list-item-checkbox">
      BB-8
    </li>
    <li class="task-list-item">
      <input type="checkbox" class="task-list-item-checkbox">
      WALL-E
    </li>
  </ul>
</task-lists>

const list = document.querySelector('task-lists')

list.addEventListener('task-lists-check', function(event) {
  const {position, checked} = event.detail
  console.log(position, checked)
})

list.addEventListener('task-lists-move', function(event) {
  const {src, dst} = event.detail
  console.log(src, dst)
})

npm install
npm test