Replace lodash with native API (theme-next#1230)

scripts/events/index.js

@@ -13,7 +13,7 @@ hexo.on('generateAfter', () => {
   if (!hexo.theme.config.reminder) return;
   const https = require('https');
   const path = require('path');
-  const env = require(path.normalize('../../package.json'));
+  const { version } = require(path.normalize('../../package.json'));
   https.get({
     hostname: 'api.github.com',
     port    : 443,
@@ -30,7 +30,7 @@ hexo.on('generateAfter', () => {
     res.on('end', () => {
       try {
         var latest = JSON.parse(result).tag_name.replace('v', '').split('.');
-        var current = env.version.split('.');
+        var current = version.split('.');
         var isOutdated = false;
         for (var i = 0; i < Math.max(latest.length, current.length); i++) {
           if (!current[i] || latest[i] > current[i]) {

scripts/events/lib/config.js

@@ -1,13 +1,26 @@
 'use strict';
 
+function isObject(item) {
+  return item && typeof item === 'object' && !Array.isArray(item);
+}
+
+function merge(target, source) {
+  for (const key in source) {
+    if (isObject(target[key]) && isObject(source[key])) {
+      merge(target[key], source[key]);
+    } else {
+      target[key] = source[key];
+    }
+  }
+  return target;
+}
+
 module.exports = hexo => {
   if (!hexo.locals.get) return;
 
   var data = hexo.locals.get('data');
   if (!data) return;
 
-  const merge = require(hexo.base_dir + 'node_modules/lodash/merge');
-
   /**
    * Merge configs from _data/next.yml into hexo.theme.config.
    * If `override`, configs in next.yml will rewrite configs in hexo.theme.config.