Improved version checker

scripts/NewVersionCheck.ts

@@ -5,16 +5,29 @@ let etags = new Map<string, string>()
 let hasNewVersion = false
 let newVersionCheckDelay = 60000
 
-export async function checkNewVersion(url: string, statusMessage: StatusMessage) {
+async function checkNewVersion(url: string, statusMessage: StatusMessage) {
 	if(hasNewVersion) {
 		return
 	}
 
 	try {
-		let response = await fetch(url)
+		let headers = {}
+
+		if(etags.has(url)) {
+			headers["If-None-Match"] = etags.get(url)
+		}
+
+		let response = await fetch(url, {
+			headers
+		})
+
+		// Not modified response
+		if(response.status === 304) {
+			return
+		}
 
 		if(!response.ok) {
-			console.warn("Error fetching", url)
+			console.warn("Error fetching", url, response.status)
 			return
 		}
 
@@ -34,8 +47,11 @@ export async function checkNewVersion(url: string, statusMessage: StatusMessage)
 		}
 	} catch(err) {
 		console.warn("Error fetching", url + "\n", err)
+	} finally {
+		checkNewVersionDelayed(url, statusMessage)
 	}
-
-	delay(newVersionCheckDelay).then(() => checkNewVersion(url, statusMessage))
 }
 
+export async function checkNewVersionDelayed(url: string, statusMessage: StatusMessage) {
+	delay(newVersionCheckDelay).then(() => checkNewVersion(url, statusMessage))
+}