hexo-修改永久链接后，如何保留旧链接

// 2021-10-15，up主修改了永久链接的规则，为了不影响之前已发布的文章链接，我们这里修改下生成文章的脚本，让之前的文章同时支持两种链接：
// - befor: `:year-:month-:day-:title`
// - after: `:year-:month-:day-:title` and `:title`
var postDateV1 = new Date("2021-10-15");

hexo.extend.generator.register("post", function (locals) {
  const posts = locals.posts.sort("-date").toArray();
  let length = locals.posts.length;
  return locals.posts
    .map(function (post, i) {
      const { path, layout } = post;
      // 不需要 layout
      if (!layout || layout === "false") {
        return {
          path,
          data: post.content,
        };
      }
      // 上一篇 / 下一篇
      if (i) post.prev = posts[i - 1];
      if (i < length - 1) post.next = posts[i + 1];

      const layouts = ["post", "page", "index"];
      if (layout !== "post") layouts.unshift(layout);
      post.__post = true; // 见源码

      // 我们最开始的目的：兼容两种 Permalink
      var date = new Date(post.date);
      if (date < postDateV1 && post.date) {
        const oldLink = post.date.format("YYYY/MM/DD/") + post.path;
        console.log("oldLink", oldLink);
        return [
          {
            path: oldLink,
            data: post,
            layout: "post",
          },
          {
            path: post.path,
            data: post,
            layout: "post",
          },
        ];
      }
      return [
        {
          path: post.path,
          data: post,
          layout: "post",
        },
      ];
    })
    .reduce(function (a, b) {
      return a.concat(b);
    });
});