Add juejin posts 增加掘金专栏文章 (#1596)

* feat: add juejin post digest

* refactor: extract utils.js

* style: reformat

* feat: add juejin posts full text

* style: fix arrow-body-style

* style: fix prettier style

lib/routes/juejin/utils.js

@@ -0,0 +1,54 @@
+const axios = require('../../utils/axios');
+const cheerio = require('cheerio');
+
+// 加载文章页
+async function load(link) {
+    const response = await axios({
+        method: 'get',
+        url: link,
+        headers: {
+            Referer: link,
+        },
+    });
+    const $ = cheerio.load(response.data);
+
+    // 解析日期
+    const date = new Date($('time').attr('datetime'));
+    const timeZone = 8 * 60;
+    const serverOffset = date.getTimezoneOffset();
+    const pubDate = new Date(date.getTime() + 60 * 1000 * (timeZone + serverOffset)).toUTCString();
+
+    // 提取内容
+    const description = $('.article-content')
+        .html()
+        .replace(/[\x00-\x08\x0b-\x0c\x0e-\x1f\x7f]/g, '')
+        .replace(/(<img.*?)(data-src)(.*?>)/g, '$1src$3');
+
+    return { description, pubDate };
+}
+
+const ProcessFeed = async (list, caches) =>
+    await Promise.all(
+        list.map(async (item) => {
+            // 列表上提取到的信息
+            const single = {
+                title: item.title,
+                description: `${(item.content || item.summaryInfo || '无描述').replace(/[\x00-\x08\x0b-\x0c\x0e-\x1f\x7f]/g, '')}`,
+                pubDate: new Date(item.createdAt).toUTCString(),
+                author: item.user.username,
+                link: item.originalUrl,
+                guid: item.originalUrl,
+            };
+
+            // 使用tryGet方法从缓存获取内容。
+            // 当缓存中无法获取到链接内容的时候，则使用load方法加载文章内容。
+            const other = await caches.tryGet(item.originalUrl, async () => await load(item.originalUrl));
+
+            // 合并解析后的结果集作为该篇文章最终的输出结果
+            return Promise.resolve(Object.assign({}, single, other));
+        })
+    );
+
+module.exports = {
+    ProcessFeed,
+};