Add Babel JavaScript compiler

Signed-off-by: Maurício Meneghini Fauth <mauricio@fauth.dev>

babel.config.json

@@ -0,0 +1,3 @@
+{
+    "presets": ["@babel/preset-env"]
+}

js/dist/.gitignore

@@ -0,0 +1,2 @@
+/*
+!/.gitignore

package.json

@@ -37,6 +37,9 @@
     "zxcvbn": "4.4.2"
   },
   "devDependencies": {
+    "@babel/cli": "^7.11.5",
+    "@babel/core": "^7.11.5",
+    "@babel/preset-env": "^7.11.5",
     "eslint": "^7.5.0",
     "eslint-plugin-compat": "^3.8.0",
     "eslint-plugin-no-jquery": "^2.5.0",
@@ -50,9 +53,10 @@
     "lodash": "^4.17.19"
   },
   "scripts": {
-    "postinstall": "yarn run --silent css-compile --quiet --style=compressed",
+    "postinstall": "yarn run --silent css-compile --quiet --style=compressed && yarn run --silent js-compile --quiet",
     "css-compile": "sass themes/pmahomme/scss:themes/pmahomme/css themes/original/scss:themes/original/css themes/metro/scss:themes/metro/css themes/bootstrap/scss:themes/bootstrap/css",
     "css-lint": "stylelint --syntax scss \"themes/**/scss/*.scss\"",
-    "js-lint": "eslint js"
+    "js-lint": "eslint js/src",
+    "js-compile": "babel js/src -d js/dist"
   }
 }

templates/scripts.twig

@@ -1,5 +1,6 @@
 {% for file in files %}
-  <script data-cfasync="false" type="text/javascript" src="{{ base_dir }}js/{{ file.filename }}
+  <script data-cfasync="false" type="text/javascript" src="{{ base_dir }}js/
+    {{- file.filename starts with 'vendor/' ? file.filename : 'dist/' ~ file.filename -}}
     {{- '.php' in file.filename ? get_common(file.params|merge({'v': version})) : '?v=' ~ version|url_encode }}"></script>
 {% endfor %}