Disable service worker in dev mode

package.json

@@ -9,7 +9,7 @@
   "scripts": {
     "setup_js_dev": "git submodule init && git submodule update && cd home-assistant-js && npm install",
     "clean": "rm -rf build/* build-temp/*",
-    "js_dev": "npm run watch_ru_all",
+    "js_dev": "script/sw-dev.js && npm run watch_ru_all",
     "js_dev_demo": "BUILD_DEMO=1 npm run watch_ru_all",
     "js_prod": "BUILD_DEV=0 npm run ru_all",
     "js_demo": "BUILD_DEV=0 BUILD_DEMO=1 npm run ru_all",

script/sw-dev.js

@@ -0,0 +1,10 @@
+#! /usr/bin/env node
+
+var fs = require('fs');
+var path = require('path');
+
+var content = `
+console.warn('Service worker disabled in dev mode');
+`;
+
+fs.writeFileSync(path.join('build', 'service_worker.js'), content);

script/sw-precache.js

@@ -1,3 +1,5 @@
+#! /usr/bin/env node
+
 /*
 Generate a caching service worker for HA