feat: concat the js files

Author: chenzhutian

index.js

@@ -50,4 +50,6 @@ if (isEnabled) {
   hexo.extend.filter.register('after_render:js', require('./lib/optimizeJS'));
 
   hexo.extend.filter.register('after_generate', require('./lib/optimizeImage'));
+
+  hexo.extend.filter.register('after_generate', require('./lib/concatJS'));
 }

lib/concatJS.js

@@ -0,0 +1,70 @@
+'use strict';
+
+const cheerio = require('cheerio');
+const Promise = require('bluebird');
+
+function concatJS(data) {
+  const hexo = this;
+  const log = hexo.log || console;
+  const routeList = this.route.list();
+
+  log.debug('===============after_generate================');
+  // 1. get all local scripts
+  const scripts = [];
+  const bundlePath = '/js/bundle.js';
+  return Promise.all(routeList.filter(path => path.endsWith('.html')).map(path => {
+    return new Promise((resolve, reject) => {
+      const html = this.route.get(path);
+      let htmlTxt = ''
+      html.on('data', (chunk) => (htmlTxt += chunk.trim()));
+      html.on('end', () => {
+        const $ = cheerio.load(htmlTxt);
+        let concat = false;
+        $('script[src]').each((idx, ele) => {
+          const $script = $(ele);
+          const src = $script.attr('src');
+          // if is local script
+          if (!src.startsWith('//') && !src.startsWith('http')) {
+            if (scripts.indexOf(src) === -1) {
+              scripts.push(src);
+            }
+            // remove the script tag from html
+            log.info('remove script %s from %s', src, path);
+            $script.remove();
+            concat = true;
+          }
+        });
+        if (concat) {
+          log.info('add script %s to %s', bundlePath, path);
+          $('body').append(`<script type="text/javascript" src="${bundlePath}"></script>`);
+          this.route.set(path, $.html());
+        }
+        log.debug('finish html, a html %s', path);
+        resolve();
+      });
+    });
+  }))
+    // 2. concat the script
+    .then(() => {
+      log.info('try to concat %s scripts', scripts.length);
+      return Promise.all(scripts.map(path => {
+        return new Promise((resolve, reject) => {
+          const script = this.route.get(path);
+          log.debug('ready concat script %s', path);
+          let scriptTxt = '';
+          script.on('data', chunk => (scriptTxt += chunk.trim()));
+          script.on('end', () => {
+            this.route.remove(path);
+            log.info('concat script %s', path);
+            resolve(scriptTxt);
+          });
+        });
+      })).then(results => {
+        const bundleScript = results.reduce((txt, script) => (txt += script), '');
+        this.route.set(bundlePath, bundleScript);
+        log.info('finish concat js script');
+      });
+    });
+}
+
+module.exports = concatJS;