修复一些小错误

module/html2md/lib.js

@@ -1,16 +1,26 @@
-global.Hydro.lib.html2md = module.exports = function html2md(str) {
+const RE_IMG = /<img.*?src="(.*?)".*?>(.*?)<\/img>/i;
+const RE_A = /<a.*?href="(.*?)".*?>(.*?)<\/a>/i;
+const RE_BLOCKQUOTE = /<blockquote.*?>(.*?)<\/blockquote>/i;
+
+function replacer(RE, cb) { // eslint-disable-line no-unused-vars
+    // eslint-disable-next-line no-eval
+    return eval(`(substr)=>{
+        const s = RE.exec(substr);
+        return cb(s);
+    }`);
+}
+
+function html2md(str) {
     return str.replace(/<p>/gmi, '').replace(/<\/p>/gmi, '  ')
-        .replace(/<h1>/gmi, '# ')
-        .replace(/<h2>/gmi, '## ')
-        .replace(/<h3>/gmi, '### ')
-        .replace(/<h4>/gmi, '#### ')
-        .replace(/<h5>/gmi, '##### ')
-        .replace(/<h6>/gmi, '###### ')
-        .replace(/<\/?code>/, '\n```\n')
-        .replace(/<img.*?src=".*?".*?>.*?<\/img>/gmi, (substr) => {
-            const RE_IMG = /<img.*?src="(.*?)".*?>(.*?)<\/img>/i;
-            const res = RE_IMG.exec(substr);
-            return `[${res[2]}](${res[1]})`;
+        .replace(/<h[1-6]>/gmi, (substr) => {
+            const s = /<h[1-6]>/i.exec(substr);
+            return `${'#'.repeat(parseInt(s[1]))} `;
         })
-        .replace(/<\/h[0-6]>/, '\n');
-};
+        .replace(/<\/h[0-6]>/, '\n')
+        .replace(/<\/?code>/, '\n```\n')
+        .replace(/<img.*?src=".*?".*?>.*?<\/img>/gmi, replacer(RE_IMG, (s) => `![${s[2]}](${s[1]})`))
+        .replace(/<a.*?href=".*?".*?>.*?<\/a>/gmi, replacer(RE_A, (s) => `[${s[2]}](${s[1]})`))
+        .replace(/<blockquote.*?>.*?<\/blockquote>/gmi, replacer(RE_BLOCKQUOTE, (s) => `> ${s[1]}`));
+}
+
+global.Hydro.lib.html2md = module.exports = html2md;