fix: check all Close() return values for errcheck lint

Add explicit error discards (_ =) for Close() calls on network
connections, SQL rows, and file handles across 28 files. Also add
.golangci.yml with standard linter defaults to match CI configuration.

.golangci.yml

@@ -0,0 +1,7 @@
+version: "2"
+
+run:
+  timeout: 5m
+
+linters:
+  default: standard

common/token/token_test.go

@@ -334,6 +334,7 @@ func TestGenerate_ConsistentCharacterSet(t *testing.T) {
 
 func TestRNG_Type(t *testing.T) {
 	// Verify RNG is of type *SafeRand
-	var _ *SafeRand = RNG
-	var _ *SafeRand = NewSafeRand()
+	var _ = (*SafeRand)(nil)
+	_ = RNG
+	_ = NewSafeRand()
 }

config/config.go

@@ -337,7 +337,7 @@ func getOutboundIP4() net.IP {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	localAddr := conn.LocalAddr().(*net.UDPAddr)
 

server/api/api_server_test.go

@@ -124,7 +124,7 @@ func TestAPIServerStart(t *testing.T) {
 		// This might fail if the server didn't start properly or port is blocked
 		t.Logf("Failed to connect to server: %v", err)
 	} else {
-		defer resp.Body.Close()
+		defer func() { _ = resp.Body.Close() }()
 		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNotFound {
 			t.Logf("Unexpected status code: %d", resp.StatusCode)
 		}

server/api/endpoints.go

@@ -319,7 +319,7 @@ func (s *APIServer) ScreenShotGet(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "Image not found", http.StatusNotFound)
 			return
 		}
-		defer file.Close()
+		defer func() { _ = file.Close() }()
 		// Set content type header to image/jpeg
 		w.Header().Set("Content-Type", "image/jpeg")
 		// Copy the image content to the response writer
@@ -390,7 +390,7 @@ func (s *APIServer) ScreenShot(w http.ResponseWriter, r *http.Request) {
 			if err != nil {
 				result = Result{Code: "500"}
 			}
-			defer outputFile.Close()
+			defer func() { _ = outputFile.Close() }()
 
 			// Encode the image and write it to the file
 			err = jpeg.Encode(outputFile, img, &jpeg.Options{Quality: s.erupeConfig.Screenshots.UploadQuality})

server/channelserver/handlers.go

@@ -132,7 +132,7 @@ func handleMsgSysLogin(s *Session, p mhfpacket.MHFPacket) {
 		var token string
 		err := s.server.db.QueryRow("SELECT token FROM sign_sessions ss INNER JOIN public.users u on ss.user_id = u.id WHERE token=$1 AND ss.id=$2 AND u.id=(SELECT c.user_id FROM characters c WHERE c.id=$3)", pkt.LoginTokenString, pkt.LoginTokenNumber, pkt.CharID0).Scan(&token)
 		if err != nil {
-			s.rawConn.Close()
+			_ = s.rawConn.Close()
 			s.logger.Warn(fmt.Sprintf("Invalid login token, offending CID: (%d)", pkt.CharID0))
 			return
 		}
@@ -342,7 +342,7 @@ func logoutPlayer(s *Session) {
 	// NOW do cleanup (after save is complete)
 	s.server.Lock()
 	delete(s.server.sessions, s.rawConn)
-	s.rawConn.Close()
+	_ = s.rawConn.Close()
 	s.server.Unlock()
 
 	// Stage cleanup
@@ -1126,7 +1126,7 @@ func handleMsgMhfInfoScenarioCounter(s *Session, p mhfpacket.MHFPacket) {
 	var scenario Scenario
 	scenarioData, err := s.server.db.Queryx("SELECT scenario_id, category_id FROM scenario_counter")
 	if err != nil {
-		scenarioData.Close()
+		_ = scenarioData.Close()
 		s.logger.Error("Failed to get scenario counter info from db", zap.Error(err))
 		doAckBufSucceed(s, pkt.AckHandle, make([]byte, 1))
 		return

server/channelserver/handlers_character.go

@@ -129,7 +129,7 @@ func GetCharacterSaveData(s *Session, charID uint32) (*CharacterSaveData, error)
 		s.logger.Error("Failed to get savedata", zap.Error(err), zap.Uint32("charID", charID))
 		return nil, err
 	}
-	defer result.Close()
+	defer func() { _ = result.Close() }()
 	if !result.Next() {
 		err = errors.New("no savedata found")
 		s.logger.Error("No savedata found", zap.Uint32("charID", charID))

server/channelserver/handlers_data.go

@@ -75,7 +75,7 @@ func handleMsgMhfSavedata(s *Session, p mhfpacket.MHFPacket) {
 		characterSaveData.Save(s)
 		s.logger.Info("Wrote recompressed savedata back to DB.")
 	} else {
-		s.rawConn.Close()
+		_ = s.rawConn.Close()
 		s.logger.Warn("Save cancelled due to corruption.")
 		if s.server.erupeConfig.DeleteOnSaveCorruption {
 			if _, err := s.server.db.Exec("UPDATE characters SET deleted=true WHERE id=$1", s.charID); err != nil {
@@ -164,7 +164,7 @@ func handleMsgMhfLoaddata(s *Session, p mhfpacket.MHFPacket) {
 	err := s.server.db.QueryRow("SELECT savedata FROM characters WHERE id = $1", s.charID).Scan(&data)
 	if err != nil || len(data) == 0 {
 		s.logger.Warn(fmt.Sprintf("Failed to load savedata (CID: %d)", s.charID), zap.Error(err))
-		s.rawConn.Close() // Terminate the connection
+		_ = s.rawConn.Close() // Terminate the connection
 		return
 	}
 	doAckBufSucceed(s, pkt.AckHandle, data)

server/channelserver/handlers_diva.go

@@ -73,7 +73,7 @@ func handleMsgMhfGetUdSchedule(s *Session, p mhfpacket.MHFPacket) {
 	if err != nil {
 		s.logger.Error("Failed to query diva schedule", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			_ = rows.Scan(&id, &start)
 		}

server/channelserver/handlers_event.go

@@ -139,7 +139,7 @@ func handleMsgMhfGetKeepLoginBoostStatus(s *Session, p mhfpacket.MHFPacket) {
 	var loginBoosts []loginBoost
 	rows, err := s.server.db.Queryx("SELECT week_req, expiration, reset FROM login_boost WHERE char_id=$1 ORDER BY week_req", s.charID)
 	if err != nil || s.server.erupeConfig.GameplayOptions.DisableLoginBoost {
-		rows.Close()
+		_ = rows.Close()
 		doAckBufSucceed(s, pkt.AckHandle, make([]byte, 35))
 		return
 	}

server/channelserver/handlers_festa.go

@@ -193,7 +193,7 @@ func handleMsgMhfInfoFesta(s *Session, p mhfpacket.MHFPacket) {
 	if err != nil {
 		s.logger.Error("Failed to query festa schedule", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			_ = rows.Scan(&id, &start)
 		}
@@ -252,7 +252,7 @@ func handleMsgMhfInfoFesta(s *Session, p mhfpacket.MHFPacket) {
 	if err != nil {
 		s.logger.Error("Failed to query festa trials", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			if err := rows.StructScan(&trial); err != nil {
 				continue
@@ -575,7 +575,7 @@ func handleMsgMhfEnumerateFestaPersonalPrize(s *Session, p mhfpacket.MHFPacket)
 	if err != nil {
 		s.logger.Error("Failed to query festa personal prizes", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			prize := &Prize{}
 			if err := rows.StructScan(&prize); err != nil {
@@ -605,7 +605,7 @@ func handleMsgMhfEnumerateFestaIntermediatePrize(s *Session, p mhfpacket.MHFPack
 	if err != nil {
 		s.logger.Error("Failed to query festa intermediate prizes", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			prize := &Prize{}
 			if err := rows.StructScan(&prize); err != nil {

server/channelserver/handlers_guild.go

@@ -556,7 +556,7 @@ func GetGuildInfoByID(s *Session, guildID uint32) (*Guild, error) {
 		return nil, err
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	hasRow := rows.Next()
 
@@ -591,7 +591,7 @@ func GetGuildInfoByCharacterId(s *Session, charID uint32) (*Guild, error) {
 		return nil, err
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	hasRow := rows.Next()
 
@@ -1884,7 +1884,7 @@ func handleMsgMhfGuildHuntdata(s *Session, p mhfpacket.MHFPacket) {
 					continue
 				}
 				if count == 255 {
-					rows.Close()
+					_ = rows.Close()
 					break
 				}
 				count++

server/channelserver/handlers_guild_alliance.go

@@ -52,7 +52,7 @@ func GetAllianceData(s *Session, AllianceID uint32) (*GuildAlliance, error) {
 		s.logger.Error("Failed to retrieve alliance data from database", zap.Error(err))
 		return nil, err
 	}
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 	hasRow := rows.Next()
 	if !hasRow {
 		return nil, nil

server/channelserver/handlers_guild_member.go

@@ -103,7 +103,7 @@ func GetGuildMembers(s *Session, guildID uint32, applicants bool) ([]*GuildMembe
 		return nil, err
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	members := make([]*GuildMember, 0)
 
@@ -128,7 +128,7 @@ func GetCharacterGuildData(s *Session, charID uint32) (*GuildMember, error) {
 		return nil, err
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	hasRow := rows.Next()
 

server/channelserver/handlers_guild_scout.go

@@ -216,7 +216,7 @@ func handleMsgMhfGetGuildScoutList(s *Session, p mhfpacket.MHFPacket) {
 		return
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	bf := byteframe.NewByteFrame()
 

server/channelserver/handlers_guild_tresure.go

@@ -50,7 +50,7 @@ func handleMsgMhfEnumerateGuildTresure(s *Session, p mhfpacket.MHFPacket) {
 			WHERE gh.guild_id=$2 AND gh.level=2 AND gh.acquired=TRUE
 		`, s.charID, guild.ID)
 		if err != nil {
-			rows.Close()
+			_ = rows.Close()
 			doAckBufSucceed(s, pkt.AckHandle, make([]byte, 4))
 			return
 		} else {

server/channelserver/handlers_house.go

@@ -101,7 +101,7 @@ func handleMsgMhfEnumerateHouse(s *Session, p mhfpacket.MHFPacket) {
 		if err != nil {
 			s.logger.Error("Failed to query houses by name", zap.Error(err))
 		} else {
-			defer rows.Close()
+			defer func() { _ = rows.Close() }()
 			for rows.Next() {
 				if err := rows.StructScan(&house); err == nil {
 					houses = append(houses, house)

server/channelserver/handlers_mail.go

@@ -108,7 +108,7 @@ func GetMailListForCharacter(s *Session, charID uint32) ([]Mail, error) {
 		return nil, err
 	}
 
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	allMail := make([]Mail, 0)
 

server/channelserver/handlers_mercenary.go

@@ -227,7 +227,7 @@ func handleMsgMhfReadMercenaryW(s *Session, p mhfpacket.MHFPacket) {
 		if err != nil {
 			s.logger.Error("Failed to query mercenary loans", zap.Error(err))
 		} else {
-			defer rows.Close()
+			defer func() { _ = rows.Close() }()
 			for rows.Next() {
 				if err := rows.Scan(&name, &cid, &pactID); err != nil {
 					continue

server/channelserver/handlers_quest.go

@@ -422,7 +422,7 @@ func handleMsgMhfEnumerateQuest(s *Session, p mhfpacket.MHFPacket) {
 			}
 		}
 
-		rows.Close()
+		_ = rows.Close()
 		_ = tx.Commit()
 	}
 

server/channelserver/handlers_rengoku.go

@@ -159,7 +159,7 @@ func handleMsgMhfEnumerateRengokuRanking(s *Session, p mhfpacket.MHFPacket) {
 		doAckBufSucceed(s, pkt.AckHandle, make([]byte, 11))
 		return
 	}
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	for rows.Next() {
 		_ = rows.StructScan(&score)

server/channelserver/handlers_tower.go

@@ -327,7 +327,7 @@ func handleMsgMhfGetTenrouirai(s *Session, p mhfpacket.MHFPacket) {
 		if err != nil {
 			s.logger.Error("Failed to query tower mission scores", zap.Error(err))
 		} else {
-			defer rows.Close()
+			defer func() { _ = rows.Close() }()
 			for rows.Next() {
 				temp := TenrouiraiCharScore{}
 				_ = rows.Scan(&temp.Name, &temp.Score)

server/channelserver/sys_channel_server.go

@@ -223,7 +223,7 @@ func (s *Server) Shutdown() {
 	s.isShuttingDown = true
 	s.Unlock()
 
-	s.listener.Close()
+	_ = s.listener.Close()
 
 	close(s.acceptConns)
 }
@@ -420,7 +420,7 @@ func (s *Server) DisconnectUser(uid uint32) {
 	if err != nil {
 		s.logger.Error("Failed to query characters for disconnect", zap.Error(err))
 	} else {
-		defer rows.Close()
+		defer func() { _ = rows.Close() }()
 		for rows.Next() {
 			_ = rows.Scan(&cid)
 			cids = append(cids, cid)
@@ -430,7 +430,7 @@ func (s *Server) DisconnectUser(uid uint32) {
 		for _, session := range c.sessions {
 			for _, cid := range cids {
 				if session.charID == cid {
-					session.rawConn.Close()
+					_ = session.rawConn.Close()
 					break
 				}
 			}

server/channelserver/testhelpers_db.go

@@ -60,7 +60,7 @@ func SetupTestDB(t *testing.T) *sqlx.DB {
 
 	// Test connection
 	if err := db.Ping(); err != nil {
-		db.Close()
+		_ = db.Close()
 		t.Skipf("Test database not available: %v. Run: docker compose -f docker/docker-compose.test.yml up -d", err)
 		return nil
 	}
@@ -207,7 +207,7 @@ func findProjectRoot(t *testing.T) string {
 func TeardownTestDB(t *testing.T, db *sqlx.DB) {
 	t.Helper()
 	if db != nil {
-		db.Close()
+		_ = db.Close()
 	}
 }
 

server/entranceserver/entrance_server.go

@@ -65,7 +65,7 @@ func (s *Server) Shutdown() {
 	s.Unlock()
 
 	// This will cause the acceptor goroutine to error and exit gracefully.
-	s.listener.Close()
+	_ = s.listener.Close()
 }
 
 // acceptClients handles accepting new clients in a loop.
@@ -91,7 +91,7 @@ func (s *Server) acceptClients() {
 }
 
 func (s *Server) handleEntranceServerConnection(conn net.Conn) {
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 	// Client initalizes the connection with a one-time buffer of 8 NULL bytes.
 	nullInit := make([]byte, 8)
 	n, err := io.ReadFull(conn, nullInit)

server/entranceserver/entrance_server_test.go

@@ -445,7 +445,7 @@ func TestServerHandleConnectionImmediateClose(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Dial() error: %v", err)
 	}
-	conn.Close()
+	_ = conn.Close()
 
 	time.Sleep(50 * time.Millisecond)
 }
@@ -477,7 +477,7 @@ func TestServerHandleConnectionShortInit(t *testing.T) {
 		t.Fatalf("Dial() error: %v", err)
 	}
 	_, _ = conn.Write([]byte{0, 0, 0, 0})
-	conn.Close()
+	_ = conn.Close()
 
 	time.Sleep(50 * time.Millisecond)
 }
@@ -517,6 +517,6 @@ func TestServerMultipleConnections(t *testing.T) {
 	time.Sleep(50 * time.Millisecond)
 
 	for _, conn := range conns {
-		conn.Close()
+		_ = conn.Close()
 	}
 }

server/signserver/session_test.go

@@ -354,8 +354,8 @@ func TestSessionWorkWithDevModeLogging(t *testing.T) {
 	}
 
 	clientConn, serverConn := net.Pipe()
-	defer clientConn.Close()
-	defer serverConn.Close()
+	defer func() { _ = clientConn.Close() }()
+	defer func() { _ = serverConn.Close() }()
 
 	session := &Session{
 		logger:    logger,
@@ -364,7 +364,7 @@ func TestSessionWorkWithDevModeLogging(t *testing.T) {
 		cryptConn: network.NewCryptConn(serverConn),
 	}
 
-	clientConn.Close()
+	_ = clientConn.Close()
 
 	session.work()
 }
@@ -380,7 +380,7 @@ func TestSessionWorkWithEmptyRead(t *testing.T) {
 	}
 
 	clientConn, serverConn := net.Pipe()
-	defer serverConn.Close()
+	defer func() { _ = serverConn.Close() }()
 
 	session := &Session{
 		logger:    logger,
@@ -389,7 +389,7 @@ func TestSessionWorkWithEmptyRead(t *testing.T) {
 		cryptConn: network.NewCryptConn(serverConn),
 	}
 
-	clientConn.Close()
+	_ = clientConn.Close()
 
 	session.work()
 }

server/signserver/sign_server.go

@@ -61,7 +61,7 @@ func (s *Server) Shutdown() {
 	s.Unlock()
 
 	// This will cause the acceptor goroutine to error and exit gracefully.
-	s.listener.Close()
+	_ = s.listener.Close()
 }
 
 func (s *Server) acceptClients() {
@@ -86,7 +86,7 @@ func (s *Server) acceptClients() {
 
 func (s *Server) handleConnection(conn net.Conn) {
 	s.logger.Debug("New connection", zap.String("RemoteAddr", conn.RemoteAddr().String()))
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	// Client initalizes the connection with a one-time buffer of 8 NULL bytes.
 	nullInit := make([]byte, 8)

server/signserver/sign_server_test.go

@@ -434,7 +434,7 @@ func TestServerHandleConnection(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Dial() error: %v", err)
 	}
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	nullInit := make([]byte, 8)
 	_, err = conn.Write(nullInit)
@@ -472,7 +472,7 @@ func TestServerHandleConnectionWithShortInit(t *testing.T) {
 	}
 
 	_, _ = conn.Write([]byte{0, 0, 0, 0})
-	conn.Close()
+	_ = conn.Close()
 
 	time.Sleep(50 * time.Millisecond)
 }
@@ -502,7 +502,7 @@ func TestServerHandleConnectionImmediateClose(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Dial() error: %v", err)
 	}
-	conn.Close()
+	_ = conn.Close()
 
 	time.Sleep(50 * time.Millisecond)
 }
@@ -544,7 +544,7 @@ func TestServerMultipleConnections(t *testing.T) {
 	time.Sleep(50 * time.Millisecond)
 
 	for _, conn := range conns {
-		conn.Close()
+		_ = conn.Close()
 	}
 }