From 21b2cffd79acb2abe66620bae351df3998ada15f Mon Sep 17 00:00:00 2001
From: vedant7007 <vedantidlgave16@gmail.com>
Date: Tue, 4 Aug 2026 10:43:42 +0530
Subject: [PATCH] fix: don't flag every user as NEW when yesterday snapshot is
 unavailable

computeRankChanges() started with an empty previousRanks and only filled it
when getYesterdaySnapshot() returned an array. That helper returns null on any
error (network, GitHub API, rate-limit, missing commit), so a single transient
failure left previousRanks empty and set rankChange = "NEW" for every user,
wiping all up/down arrows. The result is persisted to JSON, so one hiccup
sticks until the next clean run.

Guard the null/non-array case: leave rank changes neutral (0) and warn, instead
of fabricating a board-wide "NEW".

Closes #378
---
 scripts/sync-leaderboard.js | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/scripts/sync-leaderboard.js b/scripts/sync-leaderboard.js
index 9579ac1e..8db7cd2f 100644
--- a/scripts/sync-leaderboard.js
+++ b/scripts/sync-leaderboard.js
@@ -204,12 +204,26 @@ async function computeRankChanges(currentSorted, filename) {
   let previousRanks = {};
   const previousData = await getYesterdaySnapshot(filename);
 
-  if (previousData && Array.isArray(previousData)) {
-    previousData.forEach((user, idx) => {
-      previousRanks[user.id] = user.originalRank || idx + 1;
+  // getYesterdaySnapshot() returns null on ANY error (network, GitHub API,
+  // rate-limit, missing commit). Falling through with an empty previousRanks
+  // would flag EVERY user as "NEW" below, wiping all rank arrows — and that
+  // gets persisted to JSON, so one transient hiccup sticks until the next clean
+  // run. When the snapshot is unusable, leave rank changes neutral instead of
+  // fabricating a board-wide "NEW".
+  if (!previousData || !Array.isArray(previousData)) {
+    console.warn(
+      `⚠️  No usable previous snapshot for ${filename}; leaving rank changes neutral (not marking users as NEW).`,
+    );
+    currentSorted.forEach((user) => {
+      user.rankChange = 0;
     });
+    return;
   }
 
+  previousData.forEach((user, idx) => {
+    previousRanks[user.id] = user.originalRank || idx + 1;
+  });
+
   currentSorted.forEach((user, idx) => {
     const currentRank = user.originalRank || idx + 1;