编写页面辅助

// 实例化 TreeWalker 对象
let walker = document.createTreeWalker(
    document.documentElement,
    NodeFilter.SHOW_ELEMENT
);
// 遍历
let node = walker.nextNode();
while (node !== null) {
    node.style.outline = "1px solid #" + (~~(Math.random() * (1 << 24))).toString(16);
    node = walker.nextNode();
}

 获取页面所有节点

const treeWalker = document.createTreeWalker(
  document.body,
  NodeFilter.SHOW_ELEMENT,
  { acceptNode(node) { return NodeFilter.FILTER_ACCEPT; } }
);

const nodeList = [];
let currentNode = treeWalker.currentNode;

while(currentNode) {
  nodeList.push(currentNode);
  currentNode = treeWalker.nextNode();
}