🐛 Unregistering legacy service worker for old users

- legacy version of the app kept being served as the old service worker was not handled properly

static/registerSW.js

@@ -0,0 +1,14 @@
+/*
+ Solely for unregistering the old service worker used in the legacy version of the app.
+ This is necessary because the user may have the old service worker cached, and if so,
+ it would prevent the new service worker from registering.
+*/
+
+if ('serviceWorker'in navigator) {
+    window.addEventListener('load', ()=>{
+        navigator.serviceWorker.register('./sw.js', {
+            scope: './'
+        })
+    }
+    )
+}

static/sw.js

@@ -0,0 +1,20 @@
+/*
+ Solely for unregistering the old service worker used in the legacy version of the app.
+ This is necessary because the user may have the old service worker cached, and if so,
+ it would prevent the new service worker from registering.
+*/
+
+self.addEventListener('activate', event => {
+  event.waitUntil(
+    caches.keys().then(cacheNames => {
+      return Promise.all(
+        cacheNames.map(cacheName => {
+          return caches.delete(cacheName);
+        })
+      );
+    }).then(() => self.clients.claim())
+  );
+  self.registration.unregister().then(() => {
+    console.log('Service Worker unregistered.');
+  });
+});