fix: format undefined

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hexo-theme-reimu",
-  "version": "0.1.2",
+  "version": "0.2.0-beta.1",
   "description": "A Hakurei Reimu style Hexo theme",
   "repository": {
     "type": "git",

scripts/helper/articleCopyright.js

@@ -2,12 +2,12 @@ hexo.extend.helper.register("articleCopyright", (post) => {
   const authorDom = `<p><strong>本文作者：</strong>${hexo.config.author} @ ${hexo.config.title}</p>`;
   const linkDom = `<p><strong>本文链接：</strong><a href="${post.permalink}">${post.permalink}</a></p>`;
   const titleDom = `<p><strong>本文标题：</strong>${post.title}</p>`;
-  const dateDom = `<p><strong>本文发布时间：</strong>${post.date.format(
+  const dateDom = `<p><strong>本文发布时间：</strong>${post.date?.format(
     "YYYY-MM-DD HH:mm:ss"
-  )}</p>`;
-  const updatedDom = `<p><strong>本文修改时间：</strong>${post.updated.format(
+  ) ?? '未知(ﾟ⊿ﾟ)ﾂ'}</p>`;
+  const updatedDom = `<p><strong>本文修改时间：</strong>${post.updated?.format(
     "YYYY-MM-DD HH:mm:ss"
-  )}</p>`;
+  ) ?? '未知(ﾟ⊿ﾟ)ﾂ'}</p>`;
   const licenseDom = `<p><strong>本文版权：</strong>本博客所有文章除特别声明外，均采用 <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/deed.zh"><span class="icon-creative-commons"></span>BY-NC-SA</a> 许可协议。转载请注明出处！</p>`;
   if (!hexo.theme.config.article_copyright.enable) return "";
   const { author, link, title, date, updated, license } =