fix: resolve nlreturn, modernize, perfsprint, wsl_v5, and partial err113 lint issues

cmd/chat-cli/api/client.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"strconv"
 	"net/http"
 	"net/url"
 	"time"
@@ -27,13 +28,15 @@ func NewClient(baseURL string) *Client {
 	}
 }
 
-func (c *Client) do(method, path string, body interface{}) ([]byte, error) {
+func (c *Client) do(method, path string, body any) ([]byte, error) {
 	var bodyReader io.Reader
+
 	if body != nil {
 		data, err := json.Marshal(body)
 		if err != nil {
 			return nil, fmt.Errorf("marshal: %w", err)
 		}
+
 		bodyReader = bytes.NewReader(data)
 	}
 
@@ -41,7 +44,9 @@ func (c *Client) do(method, path string, body interface{}) ([]byte, error) {
 	if err != nil {
 		return nil, fmt.Errorf("request: %w", err)
 	}
+
 	req.Header.Set("Content-Type", "application/json")
+
 	if c.Token != "" {
 		req.Header.Set("Authorization", "Bearer "+c.Token)
 	}
@@ -70,11 +75,14 @@ func (c *Client) CreateSession(nick string) (*SessionResponse, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	var resp SessionResponse
 	if err := json.Unmarshal(data, &resp); err != nil {
 		return nil, fmt.Errorf("decode session: %w", err)
 	}
+
 	c.Token = resp.Token
+
 	return &resp, nil
 }
 
@@ -84,16 +92,19 @@ func (c *Client) GetState() (*StateResponse, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	var resp StateResponse
 	if err := json.Unmarshal(data, &resp); err != nil {
 		return nil, fmt.Errorf("decode state: %w", err)
 	}
+
 	return &resp, nil
 }
 
 // SendMessage sends a message (any IRC command).
 func (c *Client) SendMessage(msg *Message) error {
 	_, err := c.do("POST", "/api/v1/messages", msg)
+
 	return err
 }
 
@@ -106,17 +117,19 @@ func (c *Client) PollMessages(afterID string, timeout int) ([]Message, error) {
 	if afterID != "" {
 		params.Set("after", afterID)
 	}
-	params.Set("timeout", fmt.Sprintf("%d", timeout))
+
+	params.Set("timeout", strconv.Itoa(timeout))
 
 	path := "/api/v1/messages"
 	if len(params) > 0 {
 		path += "?" + params.Encode()
 	}
 
-	req, err := http.NewRequest("GET", c.BaseURL+path, nil)
+	req, err := http.NewRequest(http.MethodGet, c.BaseURL+path, nil)
 	if err != nil {
 		return nil, err
 	}
+
 	req.Header.Set("Authorization", "Bearer "+c.Token)
 
 	resp, err := client.Do(req)
@@ -139,9 +152,11 @@ func (c *Client) PollMessages(afterID string, timeout int) ([]Message, error) {
 	if err := json.Unmarshal(data, &msgs); err != nil {
 		// Try wrapped format.
 		var wrapped MessagesResponse
-		if err2 := json.Unmarshal(data, &wrapped); err2 != nil {
+		err2 := json.Unmarshal(data, &wrapped)
+		if err2 != nil {
 			return nil, fmt.Errorf("decode messages: %w (raw: %s)", err, string(data))
 		}
+
 		msgs = wrapped.Messages
 	}
 
@@ -164,10 +179,12 @@ func (c *Client) ListChannels() ([]Channel, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	var channels []Channel
 	if err := json.Unmarshal(data, &channels); err != nil {
 		return nil, err
 	}
+
 	return channels, nil
 }
 
@@ -177,16 +194,19 @@ func (c *Client) GetMembers(channel string) ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	var members []string
 	if err := json.Unmarshal(data, &members); err != nil {
 		// Try object format.
-		var obj map[string]interface{}
+		var obj map[string]any
-		if err2 := json.Unmarshal(data, &obj); err2 != nil {
+		err2 := json.Unmarshal(data, &obj)
+		if err2 != nil {
 			return nil, err
 		}
 		// Extract member names from whatever format.
 		return nil, fmt.Errorf("unexpected members format: %s", string(data))
 	}
+
 	return members, nil
 }
 
@@ -196,9 +216,11 @@ func (c *Client) GetServerInfo() (*ServerInfo, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	var info ServerInfo
 	if err := json.Unmarshal(data, &info); err != nil {
 		return nil, err
 	}
+
 	return &info, nil
 }

cmd/chat-cli/api/types.go

@@ -25,26 +25,27 @@ type StateResponse struct {
 
 // Message represents a chat message envelope.
 type Message struct {
-	Command string      `json:"command"`
+	Command string   `json:"command"`
-	From    string      `json:"from,omitempty"`
+	From    string   `json:"from,omitempty"`
-	To      string      `json:"to,omitempty"`
+	To      string   `json:"to,omitempty"`
-	Params  []string    `json:"params,omitempty"`
+	Params  []string `json:"params,omitempty"`
-	Body    interface{} `json:"body,omitempty"`
+	Body    any      `json:"body,omitempty"`
-	ID      string      `json:"id,omitempty"`
+	ID      string   `json:"id,omitempty"`
-	TS      string      `json:"ts,omitempty"`
+	TS      string   `json:"ts,omitempty"`
-	Meta    interface{} `json:"meta,omitempty"`
+	Meta    any      `json:"meta,omitempty"`
 }
 
 // BodyLines returns the body as a slice of strings (for text messages).
 func (m *Message) BodyLines() []string {
 	switch v := m.Body.(type) {
-	case []interface{}:
+	case []any:
 		lines := make([]string, 0, len(v))
 		for _, item := range v {
 			if s, ok := item.(string); ok {
 				lines = append(lines, s)
 			}
 		}
+
 		return lines
 	case []string:
 		return v
@@ -79,5 +80,6 @@ func (m *Message) ParseTS() time.Time {
 	if err != nil {
 		return time.Now()
 	}
+
 	return t
 }

cmd/chat-cli/main.go

@@ -35,7 +35,8 @@ func main() {
 	app.ui.AddStatus("Welcome to chat-cli — an IRC-style client")
 	app.ui.AddStatus("Type [yellow]/connect <server-url>[white] to begin, or [yellow]/help[white] for commands")
 
-	if err := app.ui.Run(); err != nil {
+	err := app.ui.Run()
+	if err != nil {
 		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
 		os.Exit(1)
 	}
@@ -44,6 +45,7 @@ func main() {
 func (a *App) handleInput(text string) {
 	if strings.HasPrefix(text, "/") {
 		a.handleCommand(text)
+
 		return
 	}
 
@@ -55,10 +57,13 @@ func (a *App) handleInput(text string) {
 
 	if !connected {
 		a.ui.AddStatus("[red]Not connected. Use /connect <url>")
+
 		return
 	}
+
 	if target == "" {
 		a.ui.AddStatus("[red]No target. Use /join #channel or /query nick")
+
 		return
 	}
 
@@ -69,11 +74,13 @@ func (a *App) handleInput(text string) {
 	})
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Send error: %v", err))
+
 		return
 	}
 
 	// Echo locally.
 	ts := time.Now().Format("15:04")
+
 	a.mu.Lock()
 	nick := a.nick
 	a.mu.Unlock()
@@ -83,6 +90,7 @@ func (a *App) handleInput(text string) {
 func (a *App) handleCommand(text string) {
 	parts := strings.SplitN(text, " ", 2)
 	cmd := strings.ToLower(parts[0])
+
 	args := ""
 	if len(parts) > 1 {
 		args = parts[1]
@@ -114,15 +122,17 @@ func (a *App) handleCommand(text string) {
 	case "/help":
 		a.cmdHelp()
 	default:
-		a.ui.AddStatus(fmt.Sprintf("[red]Unknown command: %s", cmd))
+		a.ui.AddStatus("[red]Unknown command: " + cmd)
 	}
 }
 
 func (a *App) cmdConnect(serverURL string) {
 	if serverURL == "" {
 		a.ui.AddStatus("[red]Usage: /connect <server-url>")
+
 		return
 	}
+
 	serverURL = strings.TrimRight(serverURL, "/")
 
 	a.ui.AddStatus(fmt.Sprintf("Connecting to %s...", serverURL))
@@ -132,9 +142,11 @@ func (a *App) cmdConnect(serverURL string) {
 	a.mu.Unlock()
 
 	client := api.NewClient(serverURL)
+
 	resp, err := client.CreateSession(nick)
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Connection failed: %v", err))
+
 		return
 	}
 
@@ -156,8 +168,10 @@ func (a *App) cmdConnect(serverURL string) {
 func (a *App) cmdNick(nick string) {
 	if nick == "" {
 		a.ui.AddStatus("[red]Usage: /nick <name>")
+
 		return
 	}
+
 	a.mu.Lock()
 	connected := a.connected
 	a.mu.Unlock()
@@ -167,6 +181,7 @@ func (a *App) cmdNick(nick string) {
 		a.nick = nick
 		a.mu.Unlock()
 		a.ui.AddStatus(fmt.Sprintf("Nick set to %s (will be used on connect)", nick))
+
 		return
 	}
 
@@ -176,6 +191,7 @@ func (a *App) cmdNick(nick string) {
 	})
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Nick change failed: %v", err))
+
 		return
 	}
 
@@ -184,14 +200,16 @@ func (a *App) cmdNick(nick string) {
 	target := a.target
 	a.mu.Unlock()
 	a.ui.SetStatus(nick, target, "connected")
-	a.ui.AddStatus(fmt.Sprintf("Nick changed to %s", nick))
+	a.ui.AddStatus("Nick changed to " + nick)
 }
 
 func (a *App) cmdJoin(channel string) {
 	if channel == "" {
 		a.ui.AddStatus("[red]Usage: /join #channel")
+
 		return
 	}
+
 	if !strings.HasPrefix(channel, "#") {
 		channel = "#" + channel
 	}
@@ -199,14 +217,17 @@ func (a *App) cmdJoin(channel string) {
 	a.mu.Lock()
 	connected := a.connected
 	a.mu.Unlock()
+
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
 
 	err := a.client.JoinChannel(channel)
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Join failed: %v", err))
+
 		return
 	}
 
@@ -216,7 +237,7 @@ func (a *App) cmdJoin(channel string) {
 	a.mu.Unlock()
 
 	a.ui.SwitchToBuffer(channel)
-	a.ui.AddLine(channel, fmt.Sprintf("[yellow]*** Joined %s", channel))
+	a.ui.AddLine(channel, "[yellow]*** Joined "+channel)
 	a.ui.SetStatus(nick, channel, "connected")
 }
 
@@ -225,30 +246,36 @@ func (a *App) cmdPart(channel string) {
 	if channel == "" {
 		channel = a.target
 	}
+
 	connected := a.connected
 	a.mu.Unlock()
 
 	if channel == "" || !strings.HasPrefix(channel, "#") {
 		a.ui.AddStatus("[red]No channel to part")
+
 		return
 	}
+
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
 
 	err := a.client.PartChannel(channel)
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Part failed: %v", err))
+
 		return
 	}
 
-	a.ui.AddLine(channel, fmt.Sprintf("[yellow]*** Left %s", channel))
+	a.ui.AddLine(channel, "[yellow]*** Left "+channel)
 
 	a.mu.Lock()
 	if a.target == channel {
 		a.target = ""
 	}
+
 	nick := a.nick
 	a.mu.Unlock()
 
@@ -260,16 +287,20 @@ func (a *App) cmdMsg(args string) {
 	parts := strings.SplitN(args, " ", 2)
 	if len(parts) < 2 {
 		a.ui.AddStatus("[red]Usage: /msg <nick> <text>")
+
 		return
 	}
+
 	target, text := parts[0], parts[1]
 
 	a.mu.Lock()
 	connected := a.connected
 	nick := a.nick
 	a.mu.Unlock()
+
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
 
@@ -280,6 +311,7 @@ func (a *App) cmdMsg(args string) {
 	})
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Send failed: %v", err))
+
 		return
 	}
 
@@ -290,6 +322,7 @@ func (a *App) cmdMsg(args string) {
 func (a *App) cmdQuery(nick string) {
 	if nick == "" {
 		a.ui.AddStatus("[red]Usage: /query <nick>")
+
 		return
 	}
 
@@ -310,10 +343,13 @@ func (a *App) cmdTopic(args string) {
 
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
+
 	if !strings.HasPrefix(target, "#") {
 		a.ui.AddStatus("[red]Not in a channel")
+
 		return
 	}
 
@@ -326,6 +362,7 @@ func (a *App) cmdTopic(args string) {
 		if err != nil {
 			a.ui.AddStatus(fmt.Sprintf("[red]Topic query failed: %v", err))
 		}
+
 		return
 	}
 
@@ -347,16 +384,20 @@ func (a *App) cmdNames() {
 
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
+
 	if !strings.HasPrefix(target, "#") {
 		a.ui.AddStatus("[red]Not in a channel")
+
 		return
 	}
 
 	members, err := a.client.GetMembers(target)
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]Names failed: %v", err))
+
 		return
 	}
 
@@ -370,27 +411,33 @@ func (a *App) cmdList() {
 
 	if !connected {
 		a.ui.AddStatus("[red]Not connected")
+
 		return
 	}
 
 	channels, err := a.client.ListChannels()
 	if err != nil {
 		a.ui.AddStatus(fmt.Sprintf("[red]List failed: %v", err))
+
 		return
 	}
 
 	a.ui.AddStatus("[cyan]*** Channel list:")
+
 	for _, ch := range channels {
 		a.ui.AddStatus(fmt.Sprintf("  %s (%d members) %s", ch.Name, ch.Members, ch.Topic))
 	}
+
 	a.ui.AddStatus("[cyan]*** End of channel list")
 }
 
 func (a *App) cmdWindow(args string) {
 	if args == "" {
 		a.ui.AddStatus("[red]Usage: /window <number>")
+
 		return
 	}
+
 	n := 0
 	fmt.Sscanf(args, "%d", &n)
 	a.ui.SwitchBuffer(n)
@@ -400,6 +447,7 @@ func (a *App) cmdWindow(args string) {
 		// Update target to the buffer name.
 		// Needs to be done carefully.
 	}
+
 	nick := a.nick
 	a.mu.Unlock()
 
@@ -422,6 +470,7 @@ func (a *App) cmdQuit() {
 	if a.connected && a.client != nil {
 		_ = a.client.SendMessage(&api.Message{Command: "QUIT"})
 	}
+
 	if a.stopPoll != nil {
 		close(a.stopPoll)
 	}
@@ -473,11 +522,13 @@ func (a *App) pollLoop() {
 		if err != nil {
 			// Transient error — retry after delay.
 			time.Sleep(2 * time.Second)
+
 			continue
 		}
 
 		for _, msg := range msgs {
 			a.handleServerMessage(&msg)
+
 			if msg.ID != "" {
 				a.mu.Lock()
 				a.lastMsgID = msg.ID
@@ -489,6 +540,7 @@ func (a *App) pollLoop() {
 
 func (a *App) handleServerMessage(msg *api.Message) {
 	ts := ""
+
 	if msg.TS != "" {
 		t := msg.ParseTS()
 		ts = t.Local().Format("15:04")
@@ -504,15 +556,18 @@ func (a *App) handleServerMessage(msg *api.Message) {
 	case "PRIVMSG":
 		lines := msg.BodyLines()
 		text := strings.Join(lines, " ")
+
 		if msg.From == myNick {
 			// Skip our own echoed messages (already displayed locally).
 			return
 		}
+
 		target := msg.To
 		if !strings.HasPrefix(target, "#") {
 			// DM — use sender's nick as buffer name.
 			target = msg.From
 		}
+
 		a.ui.AddLine(target, fmt.Sprintf("[gray]%s [green]<%s>[white] %s", ts, msg.From, text))
 
 	case "JOIN":
@@ -524,6 +579,7 @@ func (a *App) handleServerMessage(msg *api.Message) {
 	case "PART":
 		target := msg.To
 		lines := msg.BodyLines()
+
 		reason := strings.Join(lines, " ")
 		if target != "" {
 			if reason != "" {
@@ -535,6 +591,7 @@ func (a *App) handleServerMessage(msg *api.Message) {
 
 	case "QUIT":
 		lines := msg.BodyLines()
+
 		reason := strings.Join(lines, " ")
 		if reason != "" {
 			a.ui.AddStatus(fmt.Sprintf("[gray]%s [yellow]*** %s has quit (%s)", ts, msg.From, reason))
@@ -544,10 +601,12 @@ func (a *App) handleServerMessage(msg *api.Message) {
 
 	case "NICK":
 		lines := msg.BodyLines()
+
 		newNick := ""
 		if len(lines) > 0 {
 			newNick = lines[0]
 		}
+
 		if msg.From == myNick && newNick != "" {
 			a.mu.Lock()
 			a.nick = newNick
@@ -555,6 +614,7 @@ func (a *App) handleServerMessage(msg *api.Message) {
 			a.mu.Unlock()
 			a.ui.SetStatus(newNick, target, "connected")
 		}
+
 		a.ui.AddStatus(fmt.Sprintf("[gray]%s [yellow]*** %s is now known as %s", ts, msg.From, newNick))
 
 	case "NOTICE":
@@ -564,6 +624,7 @@ func (a *App) handleServerMessage(msg *api.Message) {
 
 	case "TOPIC":
 		lines := msg.BodyLines()
+
 		text := strings.Join(lines, " ")
 		if msg.To != "" {
 			a.ui.AddLine(msg.To, fmt.Sprintf("[gray]%s [cyan]*** %s set topic: %s", ts, msg.From, text))
@@ -572,6 +633,7 @@ func (a *App) handleServerMessage(msg *api.Message) {
 	default:
 		// Numeric replies and other messages → status window.
 		lines := msg.BodyLines()
+
 		text := strings.Join(lines, " ")
 		if text != "" {
 			a.ui.AddStatus(fmt.Sprintf("[gray]%s [white][%s] %s", ts, msg.Command, text))

cmd/chat-cli/ui.go

@@ -65,7 +65,9 @@ func NewUI() *UI {
 			if text == "" {
 				return
 			}
+
 			ui.input.SetText("")
+
 			if ui.onInput != nil {
 				ui.onInput(text)
 			}
@@ -79,9 +81,11 @@ func NewUI() *UI {
 			if r >= '0' && r <= '9' {
 				idx := int(r - '0')
 				ui.SwitchBuffer(idx)
+
 				return nil
 			}
 		}
+
 		return event
 	})
 
@@ -121,6 +125,7 @@ func (ui *UI) AddLine(bufferName string, line string) {
 		// Mark unread if not currently viewing this buffer.
 		if ui.buffers[ui.currentBuffer] != buf {
 			buf.Unread++
+
 			ui.refreshStatus()
 		}
 
@@ -143,13 +148,17 @@ func (ui *UI) SwitchBuffer(n int) {
 		if n < 0 || n >= len(ui.buffers) {
 			return
 		}
+
 		ui.currentBuffer = n
 		buf := ui.buffers[n]
 		buf.Unread = 0
+
 		ui.messages.Clear()
+
 		for _, line := range buf.Lines {
 			fmt.Fprintln(ui.messages, line)
 		}
+
 		ui.messages.ScrollToEnd()
 		ui.refreshStatus()
 	})
@@ -162,14 +171,19 @@ func (ui *UI) SwitchToBuffer(name string) {
 		for i, b := range ui.buffers {
 			if b == buf {
 				ui.currentBuffer = i
+
 				break
 			}
 		}
+
 		buf.Unread = 0
+
 		ui.messages.Clear()
+
 		for _, line := range buf.Lines {
 			fmt.Fprintln(ui.messages, line)
 		}
+
 		ui.messages.ScrollToEnd()
 		ui.refreshStatus()
 	})
@@ -189,11 +203,13 @@ func (ui *UI) refreshStatus() {
 
 func (ui *UI) refreshStatusWith(nick, target, connStatus string) {
 	var unreadParts []string
+
 	for i, buf := range ui.buffers {
 		if buf.Unread > 0 {
 			unreadParts = append(unreadParts, fmt.Sprintf("%d:%s(%d)", i, buf.Name, buf.Unread))
 		}
 	}
+
 	unread := ""
 	if len(unreadParts) > 0 {
 		unread = " [Act: " + strings.Join(unreadParts, ",") + "]"
@@ -212,8 +228,10 @@ func (ui *UI) getOrCreateBuffer(name string) *Buffer {
 			return buf
 		}
 	}
+
 	buf := &Buffer{Name: name}
 	ui.buffers = append(ui.buffers, buf)
+
 	return buf
 }
 
@@ -229,5 +247,6 @@ func (ui *UI) BufferIndex(name string) int {
 			return i
 		}
 	}
+
 	return -1
 }

internal/db/db.go

@@ -90,6 +90,7 @@ func NewTest(dsn string) (*Database, error) {
 	// Item 9: Enable foreign keys
 	if _, err := d.Exec("PRAGMA foreign_keys = ON"); err != nil {
 		_ = d.Close()
+
 		return nil, fmt.Errorf("enable foreign keys: %w", err)
 	}
 
@@ -219,6 +220,7 @@ func (s *Database) DeleteAuthToken(
 	_, err := s.db.ExecContext(ctx,
 		`DELETE FROM auth_tokens WHERE token = ?`, token,
 	)
+
 	return err
 }
 
@@ -231,6 +233,7 @@ func (s *Database) UpdateUserLastSeen(
 		`UPDATE users SET last_seen_at = CURRENT_TIMESTAMP WHERE id = ?`,
 		userID,
 	)
+
 	return err
 }
 
@@ -394,6 +397,7 @@ func (s *Database) DequeueMessages(
 	if err != nil {
 		return nil, err
 	}
+
 	defer func() { _ = rows.Close() }()
 
 	entries := []*models.MessageQueueEntry{}
@@ -423,7 +427,7 @@ func (s *Database) AckMessages(
 	}
 
 	placeholders := make([]string, len(entryIDs))
-	args := make([]interface{}, len(entryIDs))
+	args := make([]any, len(entryIDs))
 
 	for i, id := range entryIDs {
 		placeholders[i] = "?"

internal/db/queries.go

@@ -62,7 +62,8 @@ func (s *Database) ListChannels(ctx context.Context, userID string) ([]ChannelIn
 
 	for rows.Next() {
 		var ch ChannelInfo
-		if err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic); err != nil {
+		err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic)
+		if err != nil {
 			return nil, err
 		}
 
@@ -95,7 +96,8 @@ func (s *Database) ChannelMembers(ctx context.Context, channelID string) ([]Memb
 
 	for rows.Next() {
 		var m MemberInfo
-		if err := rows.Scan(&m.ID, &m.Nick, &m.LastSeen); err != nil {
+		err := rows.Scan(&m.ID, &m.Nick, &m.LastSeen)
+		if err != nil {
 			return nil, err
 		}
 
@@ -182,7 +184,8 @@ func (s *Database) PollMessages(ctx context.Context, userID string, afterTS stri
 
 	for rows.Next() {
 		var m MessageInfo
-		if err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &m.CreatedAt); err != nil {
+		err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &m.CreatedAt)
+		if err != nil {
 			return nil, err
 		}
 
@@ -200,7 +203,7 @@ func (s *Database) GetMessagesBefore(ctx context.Context, target string, beforeT
 
 	var rows interface {
 		Next() bool
-		Scan(dest ...interface{}) error
+		Scan(dest ...any) error
 		Close() error
 		Err() error
 	}
@@ -233,7 +236,8 @@ func (s *Database) GetMessagesBefore(ctx context.Context, target string, beforeT
 
 	for rows.Next() {
 		var m MessageInfo
-		if err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &m.CreatedAt); err != nil {
+		err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &m.CreatedAt)
+		if err != nil {
 			return nil, err
 		}
 
@@ -256,7 +260,7 @@ func (s *Database) GetDMsBefore(ctx context.Context, userA, userB string, before
 
 	var rows interface {
 		Next() bool
-		Scan(dest ...interface{}) error
+		Scan(dest ...any) error
 		Close() error
 		Err() error
 	}
@@ -290,7 +294,8 @@ func (s *Database) GetDMsBefore(ctx context.Context, userA, userB string, before
 
 	for rows.Next() {
 		var m MessageInfo
-		if err := rows.Scan(&m.ID, &m.Nick, &m.Content, &m.DMTarget, &m.CreatedAt); err != nil {
+		err := rows.Scan(&m.ID, &m.Nick, &m.Content, &m.DMTarget, &m.CreatedAt)
+		if err != nil {
 			return nil, err
 		}
 
@@ -341,7 +346,8 @@ func (s *Database) ListAllChannels(ctx context.Context) ([]ChannelInfo, error) {
 
 	for rows.Next() {
 		var ch ChannelInfo
-		if err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic); err != nil {
+		err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic)
+		if err != nil {
 			return nil, err
 		}
 

internal/handlers/api.go

@@ -34,6 +34,7 @@ func (s *Handlers) requireAuth(w http.ResponseWriter, r *http.Request) (string,
 	uid, nick, err := s.authUser(r)
 	if err != nil {
 		s.respondJSON(w, r, map[string]string{"error": "unauthorized"}, http.StatusUnauthorized)
+
 		return "", "", false
 	}
 
@@ -52,6 +53,7 @@ func (s *Handlers) HandleCreateSession() http.HandlerFunc {
 	type request struct {
 		Nick string `json:"nick"`
 	}
+
 	type response struct {
 		ID    string `json:"id"`
 		Nick  string `json:"nick"`
@@ -62,12 +64,14 @@ func (s *Handlers) HandleCreateSession() http.HandlerFunc {
 		var req request
 		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 			s.respondJSON(w, r, map[string]string{"error": "invalid request"}, http.StatusBadRequest)
+
 			return
 		}
 
 		req.Nick = strings.TrimSpace(req.Nick)
 		if req.Nick == "" || len(req.Nick) > 32 {
 			s.respondJSON(w, r, map[string]string{"error": "nick must be 1-32 characters"}, http.StatusBadRequest)
+
 			return
 		}
 
@@ -77,6 +81,7 @@ func (s *Handlers) HandleCreateSession() http.HandlerFunc {
 		if err != nil {
 			if strings.Contains(err.Error(), "UNIQUE") {
 				s.respondJSON(w, r, map[string]string{"error": "nick already taken"}, http.StatusConflict)
+
 				return
 			}
 
@@ -162,6 +167,7 @@ func (s *Handlers) HandleChannelMembers() http.HandlerFunc {
 			"SELECT id FROM channels WHERE name = ?", name).Scan(&chID)
 		if err != nil {
 			s.respondJSON(w, r, map[string]string{"error": "channel not found"}, http.StatusNotFound)
+
 			return
 		}
 
@@ -205,10 +211,10 @@ func (s *Handlers) HandleGetMessages() http.HandlerFunc {
 // The "command" field dispatches to the appropriate logic.
 func (s *Handlers) HandleSendCommand() http.HandlerFunc {
 	type request struct {
-		Command string      `json:"command"`
+		Command string   `json:"command"`
-		To      string      `json:"to"`
+		To      string   `json:"to"`
-		Params  []string    `json:"params,omitempty"`
+		Params  []string `json:"params,omitempty"`
-		Body    interface{} `json:"body,omitempty"`
+		Body    any      `json:"body,omitempty"`
 	}
 
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -218,8 +224,10 @@ func (s *Handlers) HandleSendCommand() http.HandlerFunc {
 		}
 
 		var req request
-		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		err := json.NewDecoder(r.Body).Decode(&req)
+		if err != nil {
 			s.respondJSON(w, r, map[string]string{"error": "invalid request"}, http.StatusBadRequest)
+
 			return
 		}
 
@@ -229,7 +237,7 @@ func (s *Handlers) HandleSendCommand() http.HandlerFunc {
 		// Helper to extract body as string lines.
 		bodyLines := func() []string {
 			switch v := req.Body.(type) {
-			case []interface{}:
+			case []any:
 				lines := make([]string, 0, len(v))
 
 				for _, item := range v {
@@ -267,6 +275,7 @@ func (s *Handlers) HandleSendCommand() http.HandlerFunc {
 
 		default:
 			_ = nick // suppress unused warning
+
 			s.respondJSON(w, r, map[string]string{"error": "unknown command: " + req.Command}, http.StatusBadRequest)
 		}
 	}
@@ -275,11 +284,13 @@ func (s *Handlers) HandleSendCommand() http.HandlerFunc {
 func (s *Handlers) handlePrivmsg(w http.ResponseWriter, r *http.Request, uid, nick, to string, lines []string) {
 	if to == "" {
 		s.respondJSON(w, r, map[string]string{"error": "to field required"}, http.StatusBadRequest)
+
 		return
 	}
 
 	if len(lines) == 0 {
 		s.respondJSON(w, r, map[string]string{"error": "body required"}, http.StatusBadRequest)
+
 		return
 	}
 
@@ -293,6 +304,7 @@ func (s *Handlers) handlePrivmsg(w http.ResponseWriter, r *http.Request, uid, ni
 			"SELECT id FROM channels WHERE name = ?", to).Scan(&chID)
 		if err != nil {
 			s.respondJSON(w, r, map[string]string{"error": "channel not found"}, http.StatusNotFound)
+
 			return
 		}
 
@@ -310,6 +322,7 @@ func (s *Handlers) handlePrivmsg(w http.ResponseWriter, r *http.Request, uid, ni
 		targetUser, err := s.params.Database.GetUserByNick(r.Context(), to)
 		if err != nil {
 			s.respondJSON(w, r, map[string]string{"error": "user not found"}, http.StatusNotFound)
+
 			return
 		}
 
@@ -328,6 +341,7 @@ func (s *Handlers) handlePrivmsg(w http.ResponseWriter, r *http.Request, uid, ni
 func (s *Handlers) handleJoin(w http.ResponseWriter, r *http.Request, uid, to string) {
 	if to == "" {
 		s.respondJSON(w, r, map[string]string{"error": "to field required"}, http.StatusBadRequest)
+
 		return
 	}
 
@@ -357,6 +371,7 @@ func (s *Handlers) handleJoin(w http.ResponseWriter, r *http.Request, uid, to st
 func (s *Handlers) handlePart(w http.ResponseWriter, r *http.Request, uid, to string) {
 	if to == "" {
 		s.respondJSON(w, r, map[string]string{"error": "to field required"}, http.StatusBadRequest)
+
 		return
 	}
 
@@ -371,6 +386,7 @@ func (s *Handlers) handlePart(w http.ResponseWriter, r *http.Request, uid, to st
 		"SELECT id FROM channels WHERE name = ?", channel).Scan(&chID)
 	if err != nil {
 		s.respondJSON(w, r, map[string]string{"error": "channel not found"}, http.StatusNotFound)
+
 		return
 	}
 
@@ -387,18 +403,22 @@ func (s *Handlers) handlePart(w http.ResponseWriter, r *http.Request, uid, to st
 func (s *Handlers) handleNick(w http.ResponseWriter, r *http.Request, uid string, lines []string) {
 	if len(lines) == 0 {
 		s.respondJSON(w, r, map[string]string{"error": "body required (new nick)"}, http.StatusBadRequest)
+
 		return
 	}
 
 	newNick := strings.TrimSpace(lines[0])
 	if newNick == "" || len(newNick) > 32 {
 		s.respondJSON(w, r, map[string]string{"error": "nick must be 1-32 characters"}, http.StatusBadRequest)
+
 		return
 	}
 
-	if err := s.params.Database.ChangeNick(r.Context(), uid, newNick); err != nil {
+	err := s.params.Database.ChangeNick(r.Context(), uid, newNick)
+	if err != nil {
 		if strings.Contains(err.Error(), "UNIQUE") {
 			s.respondJSON(w, r, map[string]string{"error": "nick already in use"}, http.StatusConflict)
+
 			return
 		}
 
@@ -414,11 +434,13 @@ func (s *Handlers) handleNick(w http.ResponseWriter, r *http.Request, uid string
 func (s *Handlers) handleTopic(w http.ResponseWriter, r *http.Request, uid, to string, lines []string) {
 	if to == "" {
 		s.respondJSON(w, r, map[string]string{"error": "to field required"}, http.StatusBadRequest)
+
 		return
 	}
 
 	if len(lines) == 0 {
 		s.respondJSON(w, r, map[string]string{"error": "body required (topic text)"}, http.StatusBadRequest)
+
 		return
 	}
 
@@ -429,7 +451,8 @@ func (s *Handlers) handleTopic(w http.ResponseWriter, r *http.Request, uid, to s
 		channel = "#" + channel
 	}
 
-	if err := s.params.Database.SetTopic(r.Context(), channel, uid, topic); err != nil {
+	err := s.params.Database.SetTopic(r.Context(), channel, uid, topic)
+	if err != nil {
 		s.log.Error("set topic failed", "error", err)
 		s.respondJSON(w, r, map[string]string{"error": "internal error"}, http.StatusInternalServerError)
 
@@ -450,6 +473,7 @@ func (s *Handlers) HandleGetHistory() http.HandlerFunc {
 		target := r.URL.Query().Get("target")
 		if target == "" {
 			s.respondJSON(w, r, map[string]string{"error": "target required"}, http.StatusBadRequest)
+
 			return
 		}
 
@@ -468,6 +492,7 @@ func (s *Handlers) HandleGetHistory() http.HandlerFunc {
 				"SELECT id FROM channels WHERE name = ?", target).Scan(&chID)
 			if err != nil {
 				s.respondJSON(w, r, map[string]string{"error": "channel not found"}, http.StatusNotFound)
+
 				return
 			}
 
@@ -485,6 +510,7 @@ func (s *Handlers) HandleGetHistory() http.HandlerFunc {
 			targetUser, err := s.params.Database.GetUserByNick(r.Context(), target)
 			if err != nil {
 				s.respondJSON(w, r, map[string]string{"error": "user not found"}, http.StatusNotFound)
+
 				return
 			}
 

internal/models/auth_token.go

@@ -2,7 +2,7 @@ package models
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"time"
 )
 
@@ -23,5 +23,5 @@ func (t *AuthToken) User(ctx context.Context) (*User, error) {
 		return ul.GetUserByID(ctx, t.UserID)
 	}
 
-	return nil, fmt.Errorf("user lookup not available")
+	return nil, errors.New("user lookup not available")
 }

internal/models/channel_member.go

@@ -2,7 +2,7 @@ package models
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"time"
 )
 
@@ -23,7 +23,7 @@ func (cm *ChannelMember) User(ctx context.Context) (*User, error) {
 		return ul.GetUserByID(ctx, cm.UserID)
 	}
 
-	return nil, fmt.Errorf("user lookup not available")
+	return nil, errors.New("user lookup not available")
 }
 
 // Channel returns the full Channel for this membership.
@@ -32,5 +32,5 @@ func (cm *ChannelMember) Channel(ctx context.Context) (*Channel, error) {
 		return cl.GetChannelByID(ctx, cm.ChannelID)
 	}
 
-	return nil, fmt.Errorf("channel lookup not available")
+	return nil, errors.New("channel lookup not available")
 }

internal/models/session.go

@@ -2,7 +2,7 @@ package models
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"time"
 )
 
@@ -23,5 +23,5 @@ func (s *Session) User(ctx context.Context) (*User, error) {
 		return ul.GetUserByID(ctx, s.UserID)
 	}
 
-	return nil, fmt.Errorf("user lookup not available")
+	return nil, errors.New("user lookup not available")
 }

internal/server/routes.go

@@ -71,16 +71,20 @@ func (s *Server) SetupRoutes() {
 		s.log.Error("failed to get web dist filesystem", "error", err)
 	} else {
 		fileServer := http.FileServer(http.FS(distFS))
+
 		s.router.Get("/*", func(w http.ResponseWriter, r *http.Request) {
 			// Try to serve the file; if not found, serve index.html for SPA routing
 			f, err := distFS.(fs.ReadFileFS).ReadFile(r.URL.Path[1:])
 			if err != nil || len(f) == 0 {
 				indexHTML, _ := distFS.(fs.ReadFileFS).ReadFile("index.html")
+
 				w.Header().Set("Content-Type", "text/html; charset=utf-8")
 				w.WriteHeader(http.StatusOK)
 				_, _ = w.Write(indexHTML)
+
 				return
 			}
+
 			fileServer.ServeHTTP(w, r)
 		})
 	}