fix: Merge head properties using deepmerge

Author: paulgv

lib/templates/plugin.js

@@ -1,5 +1,6 @@
 import Cookies from 'js-cookie';
 import cookie from 'cookie';
+import merge from 'deepmerge';
 
 export default (ctx, inject) => {
   const {
@@ -86,10 +87,7 @@ export default (ctx, inject) => {
 
   // Meta
   if (typeof currentSite.head !== 'undefined') {
-    ctx.app.head = {
-      ...ctx.app.head,
-      ...currentSite.head,
-    };
+    ctx.app.head = merge(ctx.app.head, currentSite.head);
   }
 
   // Assets helper

package.json

@@ -31,6 +31,7 @@
   },
   "dependencies": {
     "cookie": "^0.3.1",
+    "deepmerge": "^2.1.1",
     "js-cookie": "^2.2.0"
   },
   "devDependencies": {

yarn.lock

@@ -2469,7 +2469,7 @@ deep-is@~0.1.3:
   version "0.1.3"
   resolved "https://registry.yarnpkg.com/deep-is/-/deep-is-0.1.3.tgz#b369d6fb5dbc13eecf524f91b070feedc357cf34"
 
-deepmerge@^2.0.0:
+deepmerge@^2.0.0, deepmerge@^2.1.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/deepmerge/-/deepmerge-2.1.1.tgz#e862b4e45ea0555072bf51e7fd0d9845170ae768"