add leetcode articles (#1574)

lib/routes/leetcode/articles.js

@@ -0,0 +1,65 @@
+const axios = require('../../utils/axios');
+const cheerio = require('cheerio');
+const url = require('url');
+
+const host = 'https://leetcode.com';
+
+module.exports = async (ctx) => {
+    const link = 'https://leetcode.com/articles/';
+    const response = await axios.get(link);
+    const $ = cheerio.load(response.data);
+
+    const list = $('a.list-group-item')
+        .slice(0, 10)
+        .map(function() {
+            const info = {
+                title: $(this)
+                    .find('h4.media-heading')
+                    .text(),
+                link: $(this).attr('href'),
+                date: $(this)
+                    .find('p.pull-right.media-date strong')
+                    .text(),
+            };
+            return info;
+        })
+        .get();
+
+    const out = await Promise.all(
+        list.map(async (info) => {
+            const title = info.title;
+            const date = info.date;
+            const itemUrl = url.resolve(host, info.link);
+
+            const cache = await ctx.cache.get(itemUrl);
+            if (cache) {
+                return Promise.resolve(JSON.parse(cache));
+            }
+
+            const response = await axios.get(itemUrl);
+            const $ = cheerio.load(response.data);
+            const description =
+                $('#question-preview')
+                    .html()
+                    .trim() +
+                $('.article-body')
+                    .html()
+                    .trim();
+
+            const single = {
+                title: title,
+                link: itemUrl,
+                description: description,
+                pubDate: new Date(date).toUTCString(),
+            };
+            ctx.cache.set(itemUrl, JSON.stringify(single), 24 * 60 * 60);
+            return Promise.resolve(single);
+        })
+    );
+
+    ctx.state.data = {
+        title: 'leetcode文章',
+        link: link,
+        item: out,
+    };
+};