From e6c5855827e25e292b94c27dc2a261271ee1bdaf Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 17 Apr 2026 13:51:20 +0000
Subject: [PATCH] refactor: extract setCachedPreference helper to remove
 duplication in serverRotation

Agent-Logs-Url: https://github.com/Moonrend/Classworks/sessions/d254def7-bda7-413a-83b1-c553c1571523

Co-authored-by: Sunwuyuan <88357633+Sunwuyuan@users.noreply.github.com>
---
 src/utils/serverRotation.js | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/utils/serverRotation.js b/src/utils/serverRotation.js
index d720194..ebc0c97 100644
--- a/src/utils/serverRotation.js
+++ b/src/utils/serverRotation.js
@@ -25,6 +25,15 @@ const serverPreference = {
   probing: false,    // Whether a background probe is currently running
 };
 
+/**
+ * Update the preference cache to mark the given server URL as preferred.
+ * @param {string} url
+ */
+function setCachedPreference(url) {
+  serverPreference.preferred = url;
+  serverPreference.cachedAt = Date.now();
+}
+
 /**
  * Determine whether an error should trigger rotation to the next server.
  * Network errors and 5xx server errors warrant rotation.
@@ -81,8 +90,7 @@ async function updateServerPreference() {
       .filter((r) => r.latency < Infinity)
       .sort((a, b) => a.latency - b.latency);
     if (reachable.length > 0) {
-      serverPreference.preferred = reachable[0].url;
-      serverPreference.cachedAt = Date.now();
+      setCachedPreference(reachable[0].url);
     }
   } catch {
     // Probe failure is non-fatal; keep existing preference
@@ -169,8 +177,7 @@ export async function tryWithRotation(operation, options = {}) {
 
       // Remember this server as the preferred one for future requests
       if (provider === "classworkscloud") {
-        serverPreference.preferred = serverUrl;
-        serverPreference.cachedAt = Date.now();
+        setCachedPreference(serverUrl);
       }
 
       return result;