style: fix all golangci-lint issues and format code (refs #17)

Fix 380 lint violations across all Go source files including wsl_v5,
nlreturn, noinlineerr, errcheck, funlen, funcorder, tagliatelle,
perfsprint, modernize, revive, gosec, ireturn, mnd, forcetypeassert,
cyclop, and others.

Key changes:
- Split large handler/command functions into smaller methods
- Extract scan helpers for database queries
- Reorder exported/unexported methods per funcorder
- Add sentinel errors in models package
- Use camelCase JSON tags per tagliatelle defaults
- Add package comments
- Fix .gitignore to not exclude cmd/chat-cli directory

internal/db/queries.go

@@ -3,107 +3,144 @@ package db
 import (
 	"context"
 	"crypto/rand"
+	"database/sql"
 	"encoding/hex"
 	"fmt"
 	"time"
 )
 
+const (
+	defaultMessageLimit = 50
+	defaultPollLimit    = 100
+	tokenBytes          = 32
+)
+
 func generateToken() string {
-	b := make([]byte, 32)
+	b := make([]byte, tokenBytes)
 	_, _ = rand.Read(b)
+
 	return hex.EncodeToString(b)
 }
 
-// CreateUser registers a new user with the given nick and returns the user with token.
-func (s *Database) CreateUser(ctx context.Context, nick string) (int64, string, error) {
+// CreateUser registers a new user with the given nick and
+// returns the user with token.
+func (s *Database) CreateUser(
+	ctx context.Context,
+	nick string,
+) (int64, string, error) {
 	token := generateToken()
 	now := time.Now()
+
 	res, err := s.db.ExecContext(ctx,
 		"INSERT INTO users (nick, token, created_at, last_seen) VALUES (?, ?, ?, ?)",
 		nick, token, now, now)
 	if err != nil {
 		return 0, "", fmt.Errorf("create user: %w", err)
 	}
+
 	id, _ := res.LastInsertId()
+
 	return id, token, nil
 }
 
-// GetUserByToken returns user id and nick for a given auth token.
-func (s *Database) GetUserByToken(ctx context.Context, token string) (int64, string, error) {
+// GetUserByToken returns user id and nick for a given auth
+// token.
+func (s *Database) GetUserByToken(
+	ctx context.Context,
+	token string,
+) (int64, string, error) {
 	var id int64
+
 	var nick string
-	err := s.db.QueryRowContext(ctx, "SELECT id, nick FROM users WHERE token = ?", token).Scan(&id, &nick)
+
+	err := s.db.QueryRowContext(
+		ctx,
+		"SELECT id, nick FROM users WHERE token = ?",
+		token,
+	).Scan(&id, &nick)
 	if err != nil {
 		return 0, "", err
 	}
+
 	// Update last_seen
-	_, _ = s.db.ExecContext(ctx, "UPDATE users SET last_seen = ? WHERE id = ?", time.Now(), id)
+	_, _ = s.db.ExecContext(
+		ctx,
+		"UPDATE users SET last_seen = ? WHERE id = ?",
+		time.Now(), id,
+	)
+
 	return id, nick, nil
 }
 
 // GetUserByNick returns user id for a given nick.
-func (s *Database) GetUserByNick(ctx context.Context, nick string) (int64, error) {
+func (s *Database) GetUserByNick(
+	ctx context.Context,
+	nick string,
+) (int64, error) {
 	var id int64
-	err := s.db.QueryRowContext(ctx, "SELECT id FROM users WHERE nick = ?", nick).Scan(&id)
+
+	err := s.db.QueryRowContext(
+		ctx,
+		"SELECT id FROM users WHERE nick = ?",
+		nick,
+	).Scan(&id)
+
 	return id, err
 }
 
-// GetOrCreateChannel returns the channel id, creating it if needed.
-func (s *Database) GetOrCreateChannel(ctx context.Context, name string) (int64, error) {
+// GetOrCreateChannel returns the channel id, creating it if
+// needed.
+func (s *Database) GetOrCreateChannel(
+	ctx context.Context,
+	name string,
+) (int64, error) {
 	var id int64
-	err := s.db.QueryRowContext(ctx, "SELECT id FROM channels WHERE name = ?", name).Scan(&id)
+
+	err := s.db.QueryRowContext(
+		ctx,
+		"SELECT id FROM channels WHERE name = ?",
+		name,
+	).Scan(&id)
 	if err == nil {
 		return id, nil
 	}
+
 	now := time.Now()
+
 	res, err := s.db.ExecContext(ctx,
 		"INSERT INTO channels (name, created_at, updated_at) VALUES (?, ?, ?)",
 		name, now, now)
 	if err != nil {
 		return 0, fmt.Errorf("create channel: %w", err)
 	}
+
 	id, _ = res.LastInsertId()
+
 	return id, nil
 }
 
 // JoinChannel adds a user to a channel.
-func (s *Database) JoinChannel(ctx context.Context, channelID, userID int64) error {
+func (s *Database) JoinChannel(
+	ctx context.Context,
+	channelID, userID int64,
+) error {
 	_, err := s.db.ExecContext(ctx,
 		"INSERT OR IGNORE INTO channel_members (channel_id, user_id, joined_at) VALUES (?, ?, ?)",
 		channelID, userID, time.Now())
+
 	return err
 }
 
 // PartChannel removes a user from a channel.
-func (s *Database) PartChannel(ctx context.Context, channelID, userID int64) error {
+func (s *Database) PartChannel(
+	ctx context.Context,
+	channelID, userID int64,
+) error {
 	_, err := s.db.ExecContext(ctx,
 		"DELETE FROM channel_members WHERE channel_id = ? AND user_id = ?",
 		channelID, userID)
-	return err
-}
 
-// ListChannels returns all channels the user has joined.
-func (s *Database) ListChannels(ctx context.Context, userID int64) ([]ChannelInfo, error) {
-	rows, err := s.db.QueryContext(ctx,
-		`SELECT c.id, c.name, c.topic FROM channels c
-		 INNER JOIN channel_members cm ON cm.channel_id = c.id
-		 WHERE cm.user_id = ? ORDER BY c.name`, userID)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-	var channels []ChannelInfo
-	for rows.Next() {
-		var ch ChannelInfo
-		if err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic); err != nil {
-			return nil, err
-		}
-		channels = append(channels, ch)
-	}
-	if channels == nil {
-		channels = []ChannelInfo{}
-	}
-	return channels, nil
+	return err
 }
 
 // ChannelInfo is a lightweight channel representation.
@@ -113,28 +150,44 @@ type ChannelInfo struct {
 	Topic string `json:"topic"`
 }
 
-// ChannelMembers returns all members of a channel.
-func (s *Database) ChannelMembers(ctx context.Context, channelID int64) ([]MemberInfo, error) {
+// ListChannels returns all channels the user has joined.
+func (s *Database) ListChannels(
+	ctx context.Context,
+	userID int64,
+) ([]ChannelInfo, error) {
 	rows, err := s.db.QueryContext(ctx,
-		`SELECT u.id, u.nick, u.last_seen FROM users u
-		 INNER JOIN channel_members cm ON cm.user_id = u.id
-		 WHERE cm.channel_id = ? ORDER BY u.nick`, channelID)
+		`SELECT c.id, c.name, c.topic FROM channels c
+		 INNER JOIN channel_members cm ON cm.channel_id = c.id
+		 WHERE cm.user_id = ? ORDER BY c.name`, userID)
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
-	var members []MemberInfo
+
+	defer func() { _ = rows.Close() }()
+
+	var channels []ChannelInfo
+
 	for rows.Next() {
-		var m MemberInfo
-		if err := rows.Scan(&m.ID, &m.Nick, &m.LastSeen); err != nil {
+		var ch ChannelInfo
+
+		err := rows.Scan(&ch.ID, &ch.Name, &ch.Topic)
+		if err != nil {
 			return nil, err
 		}
-		members = append(members, m)
+
+		channels = append(channels, ch)
 	}
-	if members == nil {
-		members = []MemberInfo{}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
 	}
-	return members, nil
+
+	if channels == nil {
+		channels = []ChannelInfo{}
+	}
+
+	return channels, nil
 }
 
 // MemberInfo represents a channel member.
@@ -144,6 +197,46 @@ type MemberInfo struct {
 	LastSeen time.Time `json:"lastSeen"`
 }
 
+// ChannelMembers returns all members of a channel.
+func (s *Database) ChannelMembers(
+	ctx context.Context,
+	channelID int64,
+) ([]MemberInfo, error) {
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT u.id, u.nick, u.last_seen FROM users u
+		 INNER JOIN channel_members cm ON cm.user_id = u.id
+		 WHERE cm.channel_id = ? ORDER BY u.nick`, channelID)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() { _ = rows.Close() }()
+
+	var members []MemberInfo
+
+	for rows.Next() {
+		var m MemberInfo
+
+		err := rows.Scan(&m.ID, &m.Nick, &m.LastSeen)
+		if err != nil {
+			return nil, err
+		}
+
+		members = append(members, m)
+	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
+	if members == nil {
+		members = []MemberInfo{}
+	}
+
+	return members, nil
+}
+
 // MessageInfo represents a chat message.
 type MessageInfo struct {
 	ID        int64     `json:"id"`
@@ -155,11 +248,18 @@ type MessageInfo struct {
 	CreatedAt time.Time `json:"createdAt"`
 }
 
-// GetMessages returns messages for a channel, optionally after a given ID.
-func (s *Database) GetMessages(ctx context.Context, channelID int64, afterID int64, limit int) ([]MessageInfo, error) {
+// GetMessages returns messages for a channel, optionally
+// after a given ID.
+func (s *Database) GetMessages(
+	ctx context.Context,
+	channelID int64,
+	afterID int64,
+	limit int,
+) ([]MessageInfo, error) {
 	if limit <= 0 {
-		limit = 50
+		limit = defaultMessageLimit
 	}
+
 	rows, err := s.db.QueryContext(ctx,
 		`SELECT m.id, c.name, u.nick, m.content, m.created_at
 		 FROM messages m
@@ -170,128 +270,288 @@ func (s *Database) GetMessages(ctx context.Context, channelID int64, afterID int
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
+
+	defer func() { _ = rows.Close() }()
+
 	var msgs []MessageInfo
+
 	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
 		}
+
 		msgs = append(msgs, m)
 	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
 	if msgs == nil {
 		msgs = []MessageInfo{}
 	}
+
 	return msgs, nil
 }
 
 // SendMessage inserts a channel message.
-func (s *Database) SendMessage(ctx context.Context, channelID, userID int64, content string) (int64, error) {
+func (s *Database) SendMessage(
+	ctx context.Context,
+	channelID, userID int64,
+	content string,
+) (int64, error) {
 	res, err := s.db.ExecContext(ctx,
 		"INSERT INTO messages (channel_id, user_id, content, is_dm, created_at) VALUES (?, ?, ?, 0, ?)",
 		channelID, userID, content, time.Now())
 	if err != nil {
 		return 0, err
 	}
+
 	return res.LastInsertId()
 }
 
 // SendDM inserts a direct message.
-func (s *Database) SendDM(ctx context.Context, fromID, toID int64, content string) (int64, error) {
+func (s *Database) SendDM(
+	ctx context.Context,
+	fromID, toID int64,
+	content string,
+) (int64, error) {
 	res, err := s.db.ExecContext(ctx,
 		"INSERT INTO messages (user_id, content, is_dm, dm_target_id, created_at) VALUES (?, ?, 1, ?, ?)",
 		fromID, content, toID, time.Now())
 	if err != nil {
 		return 0, err
 	}
+
 	return res.LastInsertId()
 }
 
-// GetDMs returns direct messages between two users after a given ID.
-func (s *Database) GetDMs(ctx context.Context, userA, userB int64, afterID int64, limit int) ([]MessageInfo, error) {
+// GetDMs returns direct messages between two users after a
+// given ID.
+func (s *Database) GetDMs(
+	ctx context.Context,
+	userA, userB int64,
+	afterID int64,
+	limit int,
+) ([]MessageInfo, error) {
 	if limit <= 0 {
-		limit = 50
+		limit = defaultMessageLimit
 	}
+
 	rows, err := s.db.QueryContext(ctx,
 		`SELECT m.id, u.nick, m.content, t.nick, m.created_at
 		 FROM messages m
 		 INNER JOIN users u ON u.id = m.user_id
 		 INNER JOIN users t ON t.id = m.dm_target_id
 		 WHERE m.is_dm = 1 AND m.id > ?
-		 AND ((m.user_id = ? AND m.dm_target_id = ?) OR (m.user_id = ? AND m.dm_target_id = ?))
-		 ORDER BY m.id ASC LIMIT ?`, afterID, userA, userB, userB, userA, limit)
+		 AND ((m.user_id = ? AND m.dm_target_id = ?)
+		   OR (m.user_id = ? AND m.dm_target_id = ?))
+		 ORDER BY m.id ASC LIMIT ?`,
+		afterID, userA, userB, userB, userA, limit)
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
+
+	defer func() { _ = rows.Close() }()
+
 	var msgs []MessageInfo
+
 	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
 		}
+
 		m.IsDM = true
+
 		msgs = append(msgs, m)
 	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
 	if msgs == nil {
 		msgs = []MessageInfo{}
 	}
+
 	return msgs, nil
 }
 
-// PollMessages returns all new messages (channel + DM) for a user after a given ID.
-func (s *Database) PollMessages(ctx context.Context, userID int64, afterID int64, limit int) ([]MessageInfo, error) {
+// PollMessages returns all new messages (channel + DM) for
+// a user after a given ID.
+func (s *Database) PollMessages(
+	ctx context.Context,
+	userID int64,
+	afterID int64,
+	limit int,
+) ([]MessageInfo, error) {
 	if limit <= 0 {
-		limit = 100
+		limit = defaultPollLimit
 	}
+
 	rows, err := s.db.QueryContext(ctx,
-		`SELECT m.id, COALESCE(c.name, ''), u.nick, m.content, m.is_dm, COALESCE(t.nick, ''), m.created_at
+		`SELECT m.id, COALESCE(c.name, ''), u.nick, m.content,
+		        m.is_dm, COALESCE(t.nick, ''), m.created_at
 		 FROM messages m
 		 INNER JOIN users u ON u.id = m.user_id
 		 LEFT JOIN channels c ON c.id = m.channel_id
 		 LEFT JOIN users t ON t.id = m.dm_target_id
 		 WHERE m.id > ? AND (
-		   (m.is_dm = 0 AND m.channel_id IN (SELECT channel_id FROM channel_members WHERE user_id = ?))
-		   OR (m.is_dm = 1 AND (m.user_id = ? OR m.dm_target_id = ?))
+		   (m.is_dm = 0 AND m.channel_id IN
+		     (SELECT channel_id FROM channel_members
+		      WHERE user_id = ?))
+		   OR (m.is_dm = 1
+		     AND (m.user_id = ? OR m.dm_target_id = ?))
 		 )
-		 ORDER BY m.id ASC LIMIT ?`, afterID, userID, userID, userID, limit)
+		 ORDER BY m.id ASC LIMIT ?`,
+		afterID, userID, userID, userID, limit)
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
-	var msgs []MessageInfo
+
+	defer func() { _ = rows.Close() }()
+
+	msgs := make([]MessageInfo, 0)
+
 	for rows.Next() {
-		var m MessageInfo
-		var isDM int
-		if err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &isDM, &m.DMTarget, &m.CreatedAt); err != nil {
+		var (
+			m    MessageInfo
+			isDM int
+		)
+
+		err := rows.Scan(
+			&m.ID, &m.Channel, &m.Nick, &m.Content,
+			&isDM, &m.DMTarget, &m.CreatedAt,
+		)
+		if err != nil {
 			return nil, err
 		}
+
 		m.IsDM = isDM == 1
 		msgs = append(msgs, m)
 	}
-	if msgs == nil {
-		msgs = []MessageInfo{}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
 	}
+
 	return msgs, nil
 }
 
-// GetMessagesBefore returns channel messages before a given ID (for history scrollback).
-func (s *Database) GetMessagesBefore(ctx context.Context, channelID int64, beforeID int64, limit int) ([]MessageInfo, error) {
-	if limit <= 0 {
-		limit = 50
+func scanChannelMessages(
+	rows *sql.Rows,
+) ([]MessageInfo, error) {
+	var msgs []MessageInfo
+
+	for rows.Next() {
+		var m MessageInfo
+
+		err := rows.Scan(
+			&m.ID, &m.Channel, &m.Nick,
+			&m.Content, &m.CreatedAt,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		msgs = append(msgs, m)
 	}
+
+	err := rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
+	if msgs == nil {
+		msgs = []MessageInfo{}
+	}
+
+	return msgs, nil
+}
+
+func scanDMMessages(
+	rows *sql.Rows,
+) ([]MessageInfo, error) {
+	var msgs []MessageInfo
+
+	for rows.Next() {
+		var m MessageInfo
+
+		err := rows.Scan(
+			&m.ID, &m.Nick, &m.Content,
+			&m.DMTarget, &m.CreatedAt,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		m.IsDM = true
+
+		msgs = append(msgs, m)
+	}
+
+	err := rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
+	if msgs == nil {
+		msgs = []MessageInfo{}
+	}
+
+	return msgs, nil
+}
+
+func reverseMessages(msgs []MessageInfo) {
+	for i, j := 0, len(msgs)-1; i < j; i, j = i+1, j-1 {
+		msgs[i], msgs[j] = msgs[j], msgs[i]
+	}
+}
+
+// GetMessagesBefore returns channel messages before a given
+// ID (for history scrollback).
+func (s *Database) GetMessagesBefore(
+	ctx context.Context,
+	channelID int64,
+	beforeID int64,
+	limit int,
+) ([]MessageInfo, error) {
+	if limit <= 0 {
+		limit = defaultMessageLimit
+	}
+
 	var query string
+
 	var args []any
+
 	if beforeID > 0 {
-		query = `SELECT m.id, c.name, u.nick, m.content, m.created_at
+		query = `SELECT m.id, c.name, u.nick, m.content,
+		                m.created_at
 			FROM messages m
 			INNER JOIN users u ON u.id = m.user_id
 			INNER JOIN channels c ON c.id = m.channel_id
-			WHERE m.channel_id = ? AND m.is_dm = 0 AND m.id < ?
+			WHERE m.channel_id = ? AND m.is_dm = 0
+			  AND m.id < ?
 			ORDER BY m.id DESC LIMIT ?`
 		args = []any{channelID, beforeID, limit}
 	} else {
-		query = `SELECT m.id, c.name, u.nick, m.content, m.created_at
+		query = `SELECT m.id, c.name, u.nick, m.content,
+		                m.created_at
 			FROM messages m
 			INNER JOIN users u ON u.id = m.user_id
 			INNER JOIN channels c ON c.id = m.channel_id
@@ -299,116 +559,153 @@ func (s *Database) GetMessagesBefore(ctx context.Context, channelID int64, befor
 			ORDER BY m.id DESC LIMIT ?`
 		args = []any{channelID, limit}
 	}
+
 	rows, err := s.db.QueryContext(ctx, query, args...)
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
-	var msgs []MessageInfo
-	for rows.Next() {
-		var m MessageInfo
-		if err := rows.Scan(&m.ID, &m.Channel, &m.Nick, &m.Content, &m.CreatedAt); err != nil {
-			return nil, err
-		}
-		msgs = append(msgs, m)
-	}
-	if msgs == nil {
-		msgs = []MessageInfo{}
-	}
-	// Reverse to ascending order
-	for i, j := 0, len(msgs)-1; i < j; i, j = i+1, j-1 {
-		msgs[i], msgs[j] = msgs[j], msgs[i]
+
+	defer func() { _ = rows.Close() }()
+
+	msgs, scanErr := scanChannelMessages(rows)
+	if scanErr != nil {
+		return nil, scanErr
 	}
+
+	// Reverse to ascending order.
+	reverseMessages(msgs)
+
 	return msgs, nil
 }
 
-// GetDMsBefore returns DMs between two users before a given ID (for history scrollback).
-func (s *Database) GetDMsBefore(ctx context.Context, userA, userB int64, beforeID int64, limit int) ([]MessageInfo, error) {
+// GetDMsBefore returns DMs between two users before a given
+// ID (for history scrollback).
+func (s *Database) GetDMsBefore(
+	ctx context.Context,
+	userA, userB int64,
+	beforeID int64,
+	limit int,
+) ([]MessageInfo, error) {
 	if limit <= 0 {
-		limit = 50
+		limit = defaultMessageLimit
 	}
+
 	var query string
+
 	var args []any
+
 	if beforeID > 0 {
-		query = `SELECT m.id, u.nick, m.content, t.nick, m.created_at
+		query = `SELECT m.id, u.nick, m.content, t.nick,
+		                m.created_at
 			FROM messages m
 			INNER JOIN users u ON u.id = m.user_id
 			INNER JOIN users t ON t.id = m.dm_target_id
 			WHERE m.is_dm = 1 AND m.id < ?
-			AND ((m.user_id = ? AND m.dm_target_id = ?) OR (m.user_id = ? AND m.dm_target_id = ?))
+			AND ((m.user_id = ? AND m.dm_target_id = ?)
+			  OR (m.user_id = ? AND m.dm_target_id = ?))
 			ORDER BY m.id DESC LIMIT ?`
-		args = []any{beforeID, userA, userB, userB, userA, limit}
+		args = []any{
+			beforeID, userA, userB, userB, userA, limit,
+		}
 	} else {
-		query = `SELECT m.id, u.nick, m.content, t.nick, m.created_at
+		query = `SELECT m.id, u.nick, m.content, t.nick,
+		                m.created_at
 			FROM messages m
 			INNER JOIN users u ON u.id = m.user_id
 			INNER JOIN users t ON t.id = m.dm_target_id
 			WHERE m.is_dm = 1
-			AND ((m.user_id = ? AND m.dm_target_id = ?) OR (m.user_id = ? AND m.dm_target_id = ?))
+			AND ((m.user_id = ? AND m.dm_target_id = ?)
+			  OR (m.user_id = ? AND m.dm_target_id = ?))
 			ORDER BY m.id DESC LIMIT ?`
 		args = []any{userA, userB, userB, userA, limit}
 	}
+
 	rows, err := s.db.QueryContext(ctx, query, args...)
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
-	var msgs []MessageInfo
-	for rows.Next() {
-		var m MessageInfo
-		if err := rows.Scan(&m.ID, &m.Nick, &m.Content, &m.DMTarget, &m.CreatedAt); err != nil {
-			return nil, err
-		}
-		m.IsDM = true
-		msgs = append(msgs, m)
-	}
-	if msgs == nil {
-		msgs = []MessageInfo{}
-	}
-	// Reverse to ascending order
-	for i, j := 0, len(msgs)-1; i < j; i, j = i+1, j-1 {
-		msgs[i], msgs[j] = msgs[j], msgs[i]
+
+	defer func() { _ = rows.Close() }()
+
+	msgs, scanErr := scanDMMessages(rows)
+	if scanErr != nil {
+		return nil, scanErr
 	}
+
+	// Reverse to ascending order.
+	reverseMessages(msgs)
+
 	return msgs, nil
 }
 
 // ChangeNick updates a user's nickname.
-func (s *Database) ChangeNick(ctx context.Context, userID int64, newNick string) error {
+func (s *Database) ChangeNick(
+	ctx context.Context,
+	userID int64,
+	newNick string,
+) error {
 	_, err := s.db.ExecContext(ctx,
-		"UPDATE users SET nick = ? WHERE id = ?", newNick, userID)
+		"UPDATE users SET nick = ? WHERE id = ?",
+		newNick, userID)
+
 	return err
 }
 
 // SetTopic sets the topic for a channel.
-func (s *Database) SetTopic(ctx context.Context, channelName string, _ int64, topic string) error {
+func (s *Database) SetTopic(
+	ctx context.Context,
+	channelName string,
+	_ int64,
+	topic string,
+) error {
 	_, err := s.db.ExecContext(ctx,
-		"UPDATE channels SET topic = ? WHERE name = ?", topic, channelName)
+		"UPDATE channels SET topic = ? WHERE name = ?",
+		topic, channelName)
+
 	return err
 }
 
-// GetServerName returns the server name (unused, config provides this).
+// GetServerName returns the server name (unused, config
+// provides this).
 func (s *Database) GetServerName() string {
 	return ""
 }
 
 // ListAllChannels returns all channels.
-func (s *Database) ListAllChannels(ctx context.Context) ([]ChannelInfo, error) {
+func (s *Database) ListAllChannels(
+	ctx context.Context,
+) ([]ChannelInfo, error) {
 	rows, err := s.db.QueryContext(ctx,
 		"SELECT id, name, topic FROM channels ORDER BY name")
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
+
+	defer func() { _ = rows.Close() }()
+
 	var channels []ChannelInfo
+
 	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
 		}
+
 		channels = append(channels, ch)
 	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
 	if channels == nil {
 		channels = []ChannelInfo{}
 	}
+
 	return channels, nil
 }