test: compare timestamps numerically in ensureUserExists last_seen test

tests/unit/db.test.ts

@@ -179,19 +179,32 @@ describe('Database', () => {
       // First call creates the user
       ensureUserExists(rawUserId, testDb);
       const initialUser = testDb.query("SELECT * FROM users WHERE id = ?").get(normalizedId);
-      const initialLastSeen = initialUser.last_seen;
+      const initialLastSeenStr = initialUser.last_seen;
+      const initialLastSeenMs = Date.parse(initialLastSeenStr); // Convert to milliseconds
 
-      // Wait a bit to ensure timestamp changes
+      // Wait a bit to ensure timestamp potentially changes
-      await sleep(50); 
+      // Increase sleep slightly to make change more likely even if DB is fast
+      await sleep(100); 
 
       // Second call should update last_seen
       const resultId = ensureUserExists(rawUserId, testDb);
       expect(resultId).toBe(normalizedId);
 
       const updatedUser = testDb.query("SELECT * FROM users WHERE id = ?").get(normalizedId);
-      expect(updatedUser.last_seen).toBeDefined();
+      const updatedLastSeenStr = updatedUser.last_seen;
-      expect(updatedUser.last_seen).not.toBe(initialLastSeen); // last_seen should be updated
+      const updatedLastSeenMs = Date.parse(updatedLastSeenStr); // Convert to milliseconds
+
+      expect(updatedLastSeenStr).toBeDefined();
       expect(updatedUser.first_seen).toBe(initialUser.first_seen); // first_seen should NOT be updated
+      
+      // Compare timestamps numerically (milliseconds since epoch)
+      // It should be greater than or equal to the initial one.
+      // Using '>' is safer if the sleep guarantees a change.
+      expect(updatedLastSeenMs).toBeGreaterThan(initialLastSeenMs); 
+      
+      // Keep the string check just in case, but the numerical one is more reliable here
+      // This might still fail occasionally if the calls land in the exact same second.
+      // expect(updatedLastSeenStr).not.toBe(initialLastSeenStr); 
     });
 
     test('should return the normalized ID on success', () => {
@@ -200,6 +213,7 @@ describe('Database', () => {
     });
 
     test('should return null for invalid raw user ID', () => {
+      // Suppress console.error during this specific test if needed, or just check output
       const resultId = ensureUserExists('invalid-id!', testDb);
       expect(resultId).toBeNull();
       const userCount = testDb.query("SELECT COUNT(*) as count FROM users").get();