fix(serviceworker): Improve cache handling and response header management in service worker.

ts_web_serviceworker/classes.cachemanager.ts

@@ -124,7 +124,7 @@ export class CacheManager {
         });
 
         // If the response status is an error or the response is opaque, do not cache it.
-        if (newResponse.status > 299 || newResponse.type === 'opaque') {
+        if (newResponse.status > 299 || newResponse.type === 'opaque' || (newResponse.headers.get('access-control-allow-origin') === null && !matchRequest.url.startsWith(this.losslessServiceWorkerRef.serviceWindowRef.location.origin))) {
           logger.log(
             'error',
             `NOTCACHED: not caching response for ${matchRequest.url} due to status ${newResponse.status} and type ${newResponse.type}`
@@ -155,6 +155,10 @@ export class CacheManager {
           if (!headers.has('Access-Control-Allow-Origin')) {
             headers.set('Access-Control-Allow-Origin', '*');
           }
+          headers.set('Vary', 'Origin');
+          if (!headers.has('Access-Control-Expose-Headers')) {
+            headers.set('Access-Control-Expose-Headers', '*')
+          }
           if (!headers.has('Access-Control-Allow-Methods')) {
             headers.set('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
           }