From d7716a88a8857e0c9f15b92b95a153627871d7af Mon Sep 17 00:00:00 2001
From: Julien Oculi <xdrz.jot.sr@gmail.com>
Date: Thu, 18 Jul 2024 14:19:41 +0200
Subject: [PATCH] perf(pwa): :zap: change cache strategy for non-pre-cached
 resources

---
 src/serviceworker/mod.ts | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/src/serviceworker/mod.ts b/src/serviceworker/mod.ts
index ff3eaec..c5768f8 100644
--- a/src/serviceworker/mod.ts
+++ b/src/serviceworker/mod.ts
@@ -110,21 +110,28 @@ async function fetchHandler(event: FetchEvent) {
 		return cached
 	}
 
-	// Cache first and refresh
+	// Fastest and cache refresh
 	if (url.origin === location.origin && method === 'GET') {
-		const cached = await cache.match(event.request)
+		const cache = await getDynCache()
 
-		const response = fetch(event.request)
-			.then((response) => {
-				if (!response.ok) {
-					throw new Error(
-						`failed to get request: [${response.status}] ${response.statusText}`,
-					)
-				}
-				// Update cache if ok
-				cache.put(event.request, response.clone())
-				return response
-			})
+		// Get cache or throw
+		const cachedOrError = cache.match(event.request).then((response) => {
+			if (response) return response
+			throw new Error(`no cache available for "${url}"`)
+		})
+		// Fetch and cache
+		const fetchedAndCached = fetch(event.request).then((response) => {
+			cache.put(event.request, response.clone())
+			return response
+		})
+
+		// Get fastest
+		return Promise.race([cachedOrError, fetchedAndCached])
+	}
+
+	// Network only
+	return fetch(event.request)
+}
 async function getDynCache(): Promise<Cache> {
 	const version = await swStorage.getItem<number>('$sw.dyn-cache.version')
 	// Create cache