fix(TTLCache): reset insertion order on key update in set() [ GSSOC '26 ] (JhaSourav07#598)

* fix(TTLCache): reset insertion order on key update in set()

* ci: retrigger pipeline

Author: rudra3007-pro

lib/cache.ts

@@ -90,19 +90,21 @@ export class TTLCache<T> {
    * cache.set("user:1",userData,5000);
    */
   set(key: string, value: T, ttlMs: number): void {
-    // Capacity eviction (FIFO / LRU-lite)
+    if (ttlMs <= 0) throw new RangeError(`ttlMs must be positive, got ${ttlMs}`);
+
     const maxSize = this.maxSize;
     if (maxSize !== undefined && this.store.size >= maxSize && !this.store.has(key)) {
-      this.sweep(); // Remove expired entries first to free up capacity
+      this.sweep();
       if (this.store.size >= maxSize) {
-        // Find the oldest item (first inserted) and remove it
-        const oldestKey = this.store.keys().next().value;
+        const oldestKey = this.store.keys().next().value as string | undefined;
         if (oldestKey !== undefined) {
           this.store.delete(oldestKey);
         }
       }
     }
 
+    // Fix: delete first so updated keys move to end (newest position)
+    this.store.delete(key);
     this.store.set(key, { value, expiresAt: Date.now() + ttlMs });
   }