improvement: detect dev mode for Svelte compilation

package.json

@@ -8,8 +8,8 @@
     "node": "10.15.0"
   },
   "scripts": {
-    "build": "npm run clean:build && webpack --config=./webpack.prod.js",
-    "build:dev": "npm run clean:build && webpack --config=./webpack.dev.js",
+    "build": "npm run clean:build && NODE_ENV=production webpack --config=./webpack.prod.js",
+    "build:dev": "npm run clean:build && NODE_ENV=development webpack --config=./webpack.dev.js",
     "build:firebase:hosting": "npm run clean:build && NODE_ENV=production NODE_APP=firebase webpack --config=./webpack.prod.js",
     "build:firebase:hosting:dev": "npm run clean:build && NODE_ENV=development NODE_APP=firebase webpack --config=./webpack.dev.js",
     "clean:build": "rm dist/** || true",

webpack.common.js

@@ -12,6 +12,9 @@ const isFirebaseEnv = process.env.NODE_APP === 'firebase'
 const firebaseConfigFilePath = path.join(__dirname, '.firebaserc')
 const hasFirebaseConfig = fs.existsSync(firebaseConfigFilePath)
 
+const isDev = process.env.NODE_ENV === 'development'
+console.log(`Detected dev mode? ${isDev}`)
+
 if (isFirebaseEnv && hasFirebaseConfig) {
   console.info('Prepare build for Firebase hosting')
 }
@@ -43,6 +46,8 @@ module.exports = {
           loader: 'svelte-loader',
           options: {
             emitCss: false,
+            hotReload: isDev,
+            dev: isDev,
           },
         },
       },