Gulpify build pipeline (#3145)

* Gulpify build pipeline

* Update build frontend script

* Fixes

* Limit service worker to latest build

* Use shorthand

* Fix hassio build

build-scripts/gulp/service-worker.js

@@ -0,0 +1,29 @@
+// Generate service worker.
+// Based on manifest, create a file with the content as service_worker.js
+/* eslint-disable import/no-dynamic-require */
+/* eslint-disable global-require */
+const gulp = require("gulp");
+const path = require("path");
+const fs = require("fs-extra");
+const config = require("../paths.js");
+
+const swPath = path.resolve(config.root, "service_worker.js");
+
+const writeSW = (content) => fs.outputFileSync(swPath, content.trim() + "\n");
+
+gulp.task("gen-service-worker-dev", (done) => {
+  writeSW(
+    `
+console.debug('Service worker disabled in development');
+  `
+  );
+  done();
+});
+
+gulp.task("gen-service-worker-prod", (done) => {
+  fs.copySync(
+    path.resolve(config.output, "service_worker.js"),
+    path.resolve(config.root, "service_worker.js")
+  );
+  done();
+});