Enable service worker for Safari

For future reference: the preflight request must return these headers:
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, HEAD, OPTIONS
Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Authorization, Pragma, Cache-Control

Otherwise, Safari will refuse requests made inside a service worker
reporting a preflight check fail.

common/worker.js

@@ -15,11 +15,9 @@ const registerServiceWorker = async () => {
         console.log('Service worker active');
       }
     } catch (error) {
-      console.error(`Registration failed with ${error}`);
+      console.error('Registration failed', error);
     }
   }
 };
 
-if (!/^((?!chrome|android).)*safari/i.test(navigator.userAgent)) {
+registerServiceWorker();
-  registerServiceWorker();
-}

sw.js

@@ -124,17 +124,23 @@ const cacheFirst = async ({ request, preloadResponsePromise, refreshAnyway }) =>
 	}
 
 	// Next try to use (and cache) the preloaded response, if it's there
-	if (preloadResponsePromise) {
+	try {
-		const preloadResponse = await preloadResponsePromise
+		if (preloadResponsePromise) {
-		if (preloadResponse && preloadResponse.ok) {
+			const preloadResponse = await preloadResponsePromise
-			console.info('[cf] using preload response', preloadResponse)
+			if (preloadResponse && preloadResponse.ok) {
-			await putInCache(request, preloadResponse.clone())
+				console.info('[cf] using preload response', preloadResponse)
-			return preloadResponse
+				await putInCache(request, preloadResponse.clone())
-		}
+				return preloadResponse
-		else {
+			}
-			console.log('[cf] got not ok preloadResponse, ignoring', preloadResponse)
+			else {
+				console.log('[cf] got not ok preloadResponse, ignoring', preloadResponse)
+			}
 		}
 	}
+	catch (e) {
+		// Ignore as preload isn't necessarily important
+		console.error('[cf] preload response error', e)
+	}
 
 	// Next try to get the resource from the network
 	const responseFromNetwork = await fetch(request)
@@ -153,17 +159,23 @@ const cacheFirst = async ({ request, preloadResponsePromise, refreshAnyway }) =>
 
 const networkFirst = async ({ request, preloadResponsePromise }) => {
 	// First try to use (and cache) the preloaded response, if it's there
-	if (preloadResponsePromise) {
+	try {
-		const preloadResponse = await preloadResponsePromise
+		if (preloadResponsePromise) {
-		if (preloadResponse && preloadResponse.ok) {
+			const preloadResponse = await preloadResponsePromise
-			console.info('[nf] using preload response', preloadResponse)
+			if (preloadResponse && preloadResponse.ok) {
-			await putInCache(request, preloadResponse.clone())
+				console.info('[nf] using preload response', preloadResponse)
-			return preloadResponse
+				await putInCache(request, preloadResponse.clone())
-		}
+				return preloadResponse
-		else {
+			}
-			console.log('[nf] got not ok preloadResponse, ignoring', preloadResponse)
+			else {
+				console.log('[nf] got not ok preloadResponse, ignoring', preloadResponse)
+			}
 		}
 	}
+	catch (e) {
+		// Ignore as preload isn't necessarily important
+		console.error('[nf] preload response error', e)
+	}
 
 	// Next try to get the resource from the network
 	let responseFromNetwork