refactor: simplify assignIn

lib/theme/view.js

@@ -4,14 +4,6 @@ const { dirname, extname, join } = require('path');
 const yfm = require('hexo-front-matter');
 const Promise = require('bluebird');
 
-const assignIn = (target, ...sources) => {
-  let source = [];
-  sources.forEach(src => {
-    source.push(...[src, Object.getPrototypeOf(src)]);
-  });
-  return Object.assign(target, ...source);
-};
-
 function View(path, data) {
   this.path = path;
   this.source = join(this._theme.base, 'layout', path);
@@ -70,7 +62,8 @@ View.prototype._buildLocals = function(locals) {
   const data = Object.assign({}, this.data);
   delete data.layout;
   delete data._concat;
-  return assignIn({}, locals, data, {
+
+  return Object.assign({}, locals, Object.getPrototypeOf(locals), data, {
     filename: this.source
   });
 };