make stats optional and ignored by jekyll

.gitignore

@@ -16,5 +16,5 @@
 .DS_Store
 /node_modules/
 /.jekyll-cache/
-stats.html
+_stats.html
 

_vite.config.mjs

@@ -6,7 +6,14 @@ import components from 'unplugin-vue-components/vite'
 import legacy from '@vitejs/plugin-legacy'
 import { toSass } from 'sass-cast'
 import { Liquid, Tag as LiquidTag } from 'liquidjs'
-import { visualizer } from 'rollup-plugin-visualizer';
+
+const visualizer = await (async()=>{
+  if (process.env.VISUALIZER) {
+    return (await import('rollup-plugin-visualizer')).visualizer;
+  }else{
+    return (()=>null);
+  }
+})();
 
 const exposedData = ['config', 'data', 'categories'];
 const jekyllData = Object.fromEntries(exposedData.map((key) => [key, JSON.parse(process.env[`site_${key}`] || '{}')]));
@@ -101,7 +108,9 @@ export default defineConfig(({mode})=>({
     legacy({
       targets: [],
     }),
-    visualizer(),
+    visualizer({
+      filename: '_stats.html',
+    }),
   ],
   css: {
     preprocessorOptions: {

package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "format": "prettier --write \"_src/**/*.js\" \"_src/**/*.vue\""
   },
-  "devDependencies": {
+  "dependencies": {
     "@vitejs/plugin-legacy": "^5.3.2",
     "@vitejs/plugin-vue": "^5.0.4",
     "bootstrap": "^5.3.3",
@@ -13,8 +13,6 @@
     "liquidjs": "^10.10.2",
     "markup-js": "^1.5.21",
     "mustache": "^4.2.0",
-    "prettier": "^3.2.5",
-    "rollup-plugin-visualizer": "^5.12.0",
     "sass": "^1.74.1",
     "sass-cast": "^0.5.6",
     "terser": "^5.30.3",
@@ -22,5 +20,9 @@
     "unplugin-vue-components": "^0.26.0",
     "vite": "^5.2.8",
     "vite-plugin-ruby": "^5.0.0"
+  },
+  "devDependencies": {
+    "prettier": "^3.2.5",
+    "rollup-plugin-visualizer": "^5.12.0"
   }
 }