Chore: Refactor error handling and resource management across multiple files (golangci-lint)

- Updated error handling to use the error return value for resource closures in tests and functions, ensuring proper error reporting.
- Replaced direct calls to `Close()` with deferred functions that handle errors gracefully.
- Improved readability by using `strings.ReplaceAll` instead of `strings.Replace` for string manipulation.
- Enhanced network connection handling by adding default cases for unsupported network types.
- Updated HTTP response handling to use the appropriate status codes and error messages.
- Removed unused variables and commented-out code to clean up the codebase.

cmd/ingest.go

@@ -55,7 +55,7 @@ The --recent flag will only consider files with a modification date within the l
 						logger.Log().Errorf("%s: %s", path, err.Error())
 						return nil
 					}
-					defer f.Close() // #nosec
+					defer func() { _ = f.Close() }()
 
 					body, err := io.ReadAll(f)
 					if err != nil {

config/utils.go

@@ -13,7 +13,7 @@ import (
 // IsFile returns whether a file exists and is readable
 func isFile(path string) bool {
 	f, err := os.Open(filepath.Clean(path))
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 	return err == nil
 }
 

internal/dump/dump.go

@@ -39,14 +39,14 @@ func Sync(d string) error {
 
 	if URL != "" {
 		if !linkRe.MatchString(URL) {
-			return errors.New("Invalid URL")
+			return errors.New("invalid URL")
 		}
 
 		base = strings.TrimRight(URL, "/") + "/"
 	}
 
 	if base == "" && config.Database == "" {
-		return errors.New("No database or API URL specified")
+		return errors.New("no database or API URL specified")
 	}
 
 	if !tools.IsDir(outDir) {
@@ -109,7 +109,7 @@ func loadIDs() error {
 	}
 
 	if len(summary) == 0 {
-		return errors.New("No messages found")
+		return errors.New("no messages found")
 	}
 
 	return nil

internal/htmlcheck/css.go

@@ -193,10 +193,10 @@ func downloadToBytes(url string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != 200 {
-		err := fmt.Errorf("Error downloading %s", url)
+		err := fmt.Errorf("error downloading %s", url)
 		return nil, err
 	}
 

internal/htmlcheck/main.go

@@ -152,13 +152,14 @@ func (c CanIEmail) getTest(k string) (Warning, error) {
 				s.Platform = platform
 				s.Version = version
 
-				if support == "y" {
+				switch support {
+				case "y":
 					y++
 					s.Support = "yes"
-				} else if support == "n" {
+				case "n":
 					n++
 					s.Support = "no"
-				} else {
+				default:
 					p++
 					s.Support = "partial"
 

internal/pop3/functions.go

@@ -18,7 +18,7 @@ func authUser(username, password string) bool {
 
 // Send a response with debug logging
 func sendResponse(c net.Conn, m string) {
-	fmt.Fprintf(c, "%s\r\n", m)
+	_, _ = fmt.Fprintf(c, "%s\r\n", m)
 	logger.Log().Debugf("[pop3] response: %s", m)
 
 	if strings.HasPrefix(m, "-ERR ") {
@@ -29,7 +29,7 @@ func sendResponse(c net.Conn, m string) {
 
 // Send a response without debug logging (for data)
 func sendData(c net.Conn, m string) {
-	fmt.Fprintf(c, "%s\r\n", m)
+	_, _ = fmt.Fprintf(c, "%s\r\n", m)
 }
 
 // Get the latest 100 messages

internal/pop3/pop3_test.go

@@ -29,22 +29,21 @@ func TestPOP3(t *testing.T) {
 
 	// connect with bad password
 	t.Log("Testing invalid login")
-	c, err := connectBadAuth()
+	if _, err := connectBadAuth(); err == nil {
-	if err == nil {
 		t.Error("invalid login gained access")
 		return
 	}
 
 	t.Log("Testing valid login")
-	c, err = connectAuth()
+	c, err := connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	count, size, err := c.Stat()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -53,7 +52,7 @@ func TestPOP3(t *testing.T) {
 
 	// quit else we get old data
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -63,13 +62,13 @@ func TestPOP3(t *testing.T) {
 
 	c, err = connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	count, _, err = c.Stat()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -80,7 +79,7 @@ func TestPOP3(t *testing.T) {
 	for i := 1; i <= 20; i++ {
 		_, err := c.Retr(i)
 		if err != nil {
-			t.Errorf(err.Error())
+			t.Error(err.Error())
 			return
 		}
 	}
@@ -89,14 +88,14 @@ func TestPOP3(t *testing.T) {
 
 	for i := 1; i <= 25; i++ {
 		if err := c.Dele(i); err != nil {
-			t.Errorf(err.Error())
+			t.Error(err.Error())
 			return
 		}
 	}
 
 	// messages get deleted after a QUIT
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -105,7 +104,7 @@ func TestPOP3(t *testing.T) {
 
 	c, err = connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -113,7 +112,7 @@ func TestPOP3(t *testing.T) {
 
 	count, _, err = c.Stat()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -121,13 +120,13 @@ func TestPOP3(t *testing.T) {
 
 	// messages get deleted after a QUIT
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	c, err = connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -135,7 +134,7 @@ func TestPOP3(t *testing.T) {
 
 	for i := 1; i <= 25; i++ {
 		if err := c.Dele(i); err != nil {
-			t.Errorf(err.Error())
+			t.Error(err.Error())
 			return
 		}
 	}
@@ -143,31 +142,31 @@ func TestPOP3(t *testing.T) {
 	t.Log("Undeleting messages")
 
 	if err := c.Rset(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	c, err = connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	count, _, err = c.Stat()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
 	assertEqual(t, count, 25, "incorrect message count")
 
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 }
@@ -190,7 +189,7 @@ func TestAuthentication(t *testing.T) {
 	// non-authenticated connection
 	c, err := connect()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -207,7 +206,7 @@ func TestAuthentication(t *testing.T) {
 	}
 
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -216,7 +215,7 @@ func TestAuthentication(t *testing.T) {
 	// authenticated connection
 	c, err = connectAuth()
 	if err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 
@@ -233,13 +232,15 @@ func TestAuthentication(t *testing.T) {
 	}
 
 	if err := c.Quit(); err != nil {
-		t.Errorf(err.Error())
+		t.Error(err.Error())
 		return
 	}
 }
 
 func setup() {
-	auth.SetPOP3Auth("username:password")
+	if err := auth.SetPOP3Auth("username:password"); err != nil {
+		panic(err)
+	}
 	logger.NoLogging = true
 	config.MaxMessages = 0
 	config.Database = os.Getenv("MP_DATABASE")

internal/pop3/server.go

@@ -271,7 +271,7 @@ func handleTransactionCommand(conn net.Conn, cmd string, args []string, messages
 		// begins with the termination octet, the line is "byte-stuffed" by
 		// pre-pending the termination octet to that line of the response.
 		// @see: https://www.ietf.org/rfc/rfc1939.txt
-		sendData(conn, strings.Replace(string(raw), "\n.", "\n..", -1))
+		sendData(conn, strings.ReplaceAll(string(raw), "\n.", "\n.."))
 		sendResponse(conn, ".")
 	case "TOP":
 		arg, err := getSafeArg(args, 0)

internal/pop3client/client.go

@@ -422,7 +422,7 @@ func (c *Conn) Noop() error {
 // Message deletions (DELE command) are only executed by the server on a graceful
 // quit and close.
 func (c *Conn) Quit() error {
-	defer c.conn.Close()
+	defer func() { _ = c.conn.Close() }()
 
 	if _, err := c.Cmd("QUIT", false); err != nil {
 		return err

internal/prometheus/metrics.go

@@ -179,10 +179,10 @@ func StartSeparateServer() {
 func GetMode() string {
 	mode := strings.ToLower(strings.TrimSpace(config.PrometheusListen))
 
-	switch {
+	switch mode {
-	case mode == "false", mode == "":
+	case "false", "":
 		return "disabled"
-	case mode == "true":
+	case "true":
 		return "integrated"
 	default:
 		return "separate"

internal/smtpd/forward.go

@@ -37,7 +37,7 @@ func createForwardingSMTPClient(config config.SMTPForwardConfigStruct, addr stri
 
 		client, err := smtp.NewClient(conn, tlsConf.ServerName)
 		if err != nil {
-			conn.Close()
+			_ = conn.Close()
 			return nil, fmt.Errorf("SMTP client error: %v", err)
 		}
 
@@ -55,7 +55,7 @@ func createForwardingSMTPClient(config config.SMTPForwardConfigStruct, addr stri
 		tlsConf.InsecureSkipVerify = config.AllowInsecure
 
 		if err = client.StartTLS(tlsConf); err != nil {
-			client.Close()
+			_ = client.Close()
 			return nil, fmt.Errorf("error creating StartTLS config: %v", err)
 		}
 	}
@@ -72,7 +72,7 @@ func forward(from string, msg []byte) error {
 	if err != nil {
 		return err
 	}
-	defer c.Close()
+	defer func() { _ = c.Close() }()
 
 	auth := forwardAuthFromConfig()
 

internal/smtpd/relay.go

@@ -71,7 +71,7 @@ func createRelaySMTPClient(config config.SMTPRelayConfigStruct, addr string) (*s
 
 		client, err := smtp.NewClient(conn, tlsConf.ServerName)
 		if err != nil {
-			conn.Close()
+			_ = conn.Close()
 			return nil, fmt.Errorf("SMTP client error: %v", err)
 		}
 
@@ -89,7 +89,7 @@ func createRelaySMTPClient(config config.SMTPRelayConfigStruct, addr string) (*s
 		tlsConf.InsecureSkipVerify = config.AllowInsecure
 
 		if err = client.StartTLS(tlsConf); err != nil {
-			client.Close()
+			_ = client.Close()
 			return nil, fmt.Errorf("error creating StartTLS config: %v", err)
 		}
 	}
@@ -106,7 +106,7 @@ func Relay(from string, to []string, msg []byte) error {
 	if err != nil {
 		return err
 	}
-	defer c.Close()
+	defer func() { _ = c.Close() }()
 
 	auth := relayAuthFromConfig()
 
@@ -193,7 +193,7 @@ func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
 		case "Password:":
 			return []byte(a.password), nil
 		default:
-			return nil, errors.New("Unknown fromServer")
+			return nil, errors.New("unknown fromServer")
 		}
 	}
 

internal/smtpd/smtpd.go

@@ -217,7 +217,7 @@ func (srv *Server) Serve(ln net.Listener) error {
 		return ErrServerClosed
 	}
 
-	defer ln.Close()
+	defer func() { _ = ln.Close() }()
 
 	for {
 		// if we are shutting down, don't accept new connections
@@ -229,7 +229,7 @@ func (srv *Server) Serve(ln net.Listener) error {
 
 		conn, err := ln.Accept()
 		if err != nil {
-			if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
+			if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
 				continue
 			}
 			return err
@@ -356,7 +356,9 @@ func (srv *Server) Shutdown(ctx context.Context) error {
 // Function called to handle connection requests.
 func (s *session) serve() {
 	defer atomic.AddInt32(&s.srv.openSessions, -1)
-	defer s.conn.Close()
+	// pass the connection into the defer function to ensure it is closed,
+	// otherwise results in a 5s timeout for each connection
+	defer func(c net.Conn) { _ = c.Close() }(s.conn)
 
 	var from string
 	var gotFrom bool
@@ -517,9 +519,9 @@ loop:
 			// On other errors, allow the client to try again.
 			data, err := s.readData()
 			if err != nil {
-				switch err.(type) {
+				switch err := err.(type) {
 				case net.Error:
-					if err.(net.Error).Timeout() {
+					if err.Timeout() {
 						s.writef("421 4.4.2 %s %s ESMTP Service closing transmission channel after timeout exceeded", s.srv.Hostname, s.srv.AppName)
 					}
 					break loop
@@ -749,7 +751,7 @@ func (s *session) writef(format string, args ...interface{}) {
 	}
 
 	line := fmt.Sprintf(format, args...)
-	fmt.Fprintf(s.bw, "%s\r\n", line)
+	_, _ = fmt.Fprintf(s.bw, "%s\r\n", line)
 	_ = s.bw.Flush()
 
 	if Debug {

internal/smtpd/smtpd_test.go

@@ -12,7 +12,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"os"
 	"reflect"
 	"regexp"
 	"strings"
@@ -40,7 +39,7 @@ func newConn(t *testing.T, server *Server) net.Conn {
 
 // Send a command and verify the 3 digit code from the response.
 func cmdCode(t *testing.T, conn net.Conn, cmd string, code string) string {
-	fmt.Fprintf(conn, "%s\r\n", cmd)
+	_, _ = fmt.Fprintf(conn, "%s\r\n", cmd)
 	resp, err := bufio.NewReader(conn).ReadString('\n')
 	if err != nil {
 		t.Fatalf("Failed to read response from test server: %v", err)
@@ -72,7 +71,9 @@ func TestSimpleCommands(t *testing.T) {
 		conn := newConn(t, &Server{})
 		cmdCode(t, conn, tt.cmd, tt.code)
 		cmdCode(t, conn, "QUIT", "221")
-		conn.Close()
+		if err := conn.Close(); err != nil {
+			t.Errorf("Failed to close connection after command %s: %v", tt.cmd, err)
+		}
 	}
 }
 
@@ -90,7 +91,7 @@ func TestCmdHELO(t *testing.T) {
 	cmdCode(t, conn, "DATA", "503")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdEHLO(t *testing.T) {
@@ -107,7 +108,7 @@ func TestCmdEHLO(t *testing.T) {
 	cmdCode(t, conn, "DATA", "503")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdRSET(t *testing.T) {
@@ -121,7 +122,7 @@ func TestCmdRSET(t *testing.T) {
 	cmdCode(t, conn, "DATA", "503")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdMAIL(t *testing.T) {
@@ -162,7 +163,7 @@ func TestCmdMAIL(t *testing.T) {
 	// TODO: MAIL with invalid AUTH parameter must return 501 syntax error
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdMAILMaxSize(t *testing.T) {
@@ -192,7 +193,7 @@ func TestCmdMAILMaxSize(t *testing.T) {
 
 	// Clients should send either RSET or QUIT after receiving 552 (RFC 1870 section 6.2).
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdRCPT(t *testing.T) {
@@ -239,7 +240,7 @@ func TestCmdRCPT(t *testing.T) {
 	cmdCode(t, conn, "RCPT TO:  <recipient@example.com>", "501")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdMaxRecipients(t *testing.T) {
@@ -256,7 +257,7 @@ func TestCmdMaxRecipients(t *testing.T) {
 	cmdCode(t, conn, "RCPT TO: <recipient5@example.com>", "452")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdDATA(t *testing.T) {
@@ -286,7 +287,7 @@ func TestCmdDATA(t *testing.T) {
 	cmdCode(t, conn, "Test message.\r\n.", "250")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdDATAWithMaxSize(t *testing.T) {
@@ -323,7 +324,7 @@ func TestCmdDATAWithMaxSize(t *testing.T) {
 
 	// Clients should send either RSET or QUIT after receiving 552 (RFC 1870 section 6.2).
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 type mockHandler struct {
@@ -347,7 +348,7 @@ func TestCmdDATAWithHandler(t *testing.T) {
 	cmdCode(t, conn, "DATA", "354")
 	cmdCode(t, conn, "Test message.\r\n.", "250")
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 
 	if m.handlerCalled != 1 {
 		t.Errorf("MailHandler called %d times, want one call", m.handlerCalled)
@@ -364,7 +365,7 @@ func TestCmdDATAWithHandlerError(t *testing.T) {
 	cmdCode(t, conn, "DATA", "354")
 	cmdCode(t, conn, "Test message.\r\n.", "451")
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 
 	if m.handlerCalled != 1 {
 		t.Errorf("MailHandler called %d times, want one call", m.handlerCalled)
@@ -382,7 +383,7 @@ func TestCmdSTARTTLS(t *testing.T) {
 	cmdCode(t, conn, "STARTTLS FOO", "501")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdSTARTTLSFailure(t *testing.T) {
@@ -411,7 +412,7 @@ func TestCmdSTARTTLSFailure(t *testing.T) {
 	}
 
 	cmdCode(t, conn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 // Utility function to make a valid TLS certificate for use by the server.
@@ -497,7 +498,7 @@ func TestCmdSTARTTLSSuccess(t *testing.T) {
 	cmdCode(t, tlsConn, "STARTTLS", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdSTARTTLSRequired(t *testing.T) {
@@ -548,7 +549,7 @@ func TestCmdSTARTTLSRequired(t *testing.T) {
 	}
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestMakeHeaders(t *testing.T) {
@@ -798,8 +799,8 @@ func TestMakeEHLOResponse(t *testing.T) {
 		t.Errorf("AUTH does not appear in the extension list when an AuthHandler is specified")
 	}
 
-	reLogin := regexp.MustCompile("\\bLOGIN\\b")
+	reLogin := regexp.MustCompile(`\bLOGIN\b`)
-	rePlain := regexp.MustCompile("\\bPLAIN\\b")
+	rePlain := regexp.MustCompile(`\bPLAIN\b`)
 
 	// RFC 4954 specifies that, without TLS in use, plaintext authentication mechanisms must not be advertised.
 	s.tls = false
@@ -822,86 +823,86 @@ func TestMakeEHLOResponse(t *testing.T) {
 	}
 }
 
-func createTmpFile(content string) (file *os.File, err error) {
+// func createTmpFile(content string) (file *os.File, err error) {
-	file, err = os.CreateTemp("", "")
+// 	file, err = os.CreateTemp("", "")
-	if err != nil {
+// 	if err != nil {
-		return
+// 		return
-	}
+// 	}
-	_, err = file.Write([]byte(content))
+// 	_, err = file.Write([]byte(content))
-	if err != nil {
+// 	if err != nil {
-		return
+// 		return
-	}
+// 	}
-	err = file.Close()
+// 	err = file.Close()
-	return
+// 	return
-}
+// }
 
-func createTLSFiles() (
+// func createTLSFiles() (
-	certFile *os.File,
+// 	certFile *os.File,
-	keyFile *os.File,
+// 	keyFile *os.File,
-	passphrase string,
+// 	passphrase string,
-	err error,
+// 	err error,
-) {
+// ) {
-	const certPEM = `-----BEGIN CERTIFICATE-----
+// 	const certPEM = `-----BEGIN CERTIFICATE-----
-MIIDRzCCAi+gAwIBAgIJAKtg4oViVwv4MA0GCSqGSIb3DQEBCwUAMBQxEjAQBgNV
+// MIIDRzCCAi+gAwIBAgIJAKtg4oViVwv4MA0GCSqGSIb3DQEBCwUAMBQxEjAQBgNV
-BAMMCWxvY2FsaG9zdDAgFw0xODA0MjAxMzMxNTBaGA8yMDg2MDUwODEzMzE1MFow
+// BAMMCWxvY2FsaG9zdDAgFw0xODA0MjAxMzMxNTBaGA8yMDg2MDUwODEzMzE1MFow
-FDESMBAGA1UEAwwJbG9jYWxob3N0MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB
+// FDESMBAGA1UEAwwJbG9jYWxob3N0MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB
-CgKCAQEA8h7vl0gUquis5jRtcnETyD+8WITZO0s53aIzp0Y+9HXiHW6FGJjbOZjM
+// CgKCAQEA8h7vl0gUquis5jRtcnETyD+8WITZO0s53aIzp0Y+9HXiHW6FGJjbOZjM
-IvozNVni+83QWKumRTgeSzIIW2j4V8iFMSNrvWmhmCKloesXS1aY6H979e01Ve8J
+// IvozNVni+83QWKumRTgeSzIIW2j4V8iFMSNrvWmhmCKloesXS1aY6H979e01Ve8J
-WAJFRe6vZJd6gC6Z/P+ELU3ie4Vtr1GYfkV7nZ6VFp5/V/5nxGFag5TUlpP5hcoS
+// WAJFRe6vZJd6gC6Z/P+ELU3ie4Vtr1GYfkV7nZ6VFp5/V/5nxGFag5TUlpP5hcoS
-9r2kvXofosVwe3x3udT8SEbv5eBD4bKeVyJs/RLbxSuiU1358Y1cDdVuHjcvfm3c
+// 9r2kvXofosVwe3x3udT8SEbv5eBD4bKeVyJs/RLbxSuiU1358Y1cDdVuHjcvfm3c
-ajhheQ4vX9WXsk7LGGhnf1SrrPN/y+IDTXfvoHn+nJh4vMAB4yzQdE1V1N1AB8RA
+// ajhheQ4vX9WXsk7LGGhnf1SrrPN/y+IDTXfvoHn+nJh4vMAB4yzQdE1V1N1AB8RA
-0yBVJ6dwxRrSg4BFrNWhj3gfsvrA7wIDAQABo4GZMIGWMB0GA1UdDgQWBBQ4/ncp
+// 0yBVJ6dwxRrSg4BFrNWhj3gfsvrA7wIDAQABo4GZMIGWMB0GA1UdDgQWBBQ4/ncp
-befFuKH1hoYkPqLwuRrPRjAfBgNVHSMEGDAWgBQ4/ncpbefFuKH1hoYkPqLwuRrP
+// befFuKH1hoYkPqLwuRrPRjAfBgNVHSMEGDAWgBQ4/ncpbefFuKH1hoYkPqLwuRrP
-RjAJBgNVHRMEAjAAMBEGCWCGSAGG+EIBAQQEAwIGQDALBgNVHQ8EBAMCBaAwEwYD
+// RjAJBgNVHRMEAjAAMBEGCWCGSAGG+EIBAQQEAwIGQDALBgNVHQ8EBAMCBaAwEwYD
-VR0lBAwwCgYIKwYBBQUHAwEwFAYDVR0RBA0wC4IJbG9jYWxob3N0MA0GCSqGSIb3
+// VR0lBAwwCgYIKwYBBQUHAwEwFAYDVR0RBA0wC4IJbG9jYWxob3N0MA0GCSqGSIb3
-DQEBCwUAA4IBAQBJBetEXiEIzKAEpXGX87j6aUON51Fdf6BiLMCghuGKyhnaOG32
+// DQEBCwUAA4IBAQBJBetEXiEIzKAEpXGX87j6aUON51Fdf6BiLMCghuGKyhnaOG32
-4KJhtvVoS3ZUKPylh9c2VdItYlhWp76zd7YKk+3xUOixWeTMQHIvCvRGTyFibOPT
+// 4KJhtvVoS3ZUKPylh9c2VdItYlhWp76zd7YKk+3xUOixWeTMQHIvCvRGTyFibOPT
-mApwp2pEnJCe4vjUrBaRhiyI+xnB70cWVF2qeernlLUeJA1mfYyQLz+v06ebDWOL
+// mApwp2pEnJCe4vjUrBaRhiyI+xnB70cWVF2qeernlLUeJA1mfYyQLz+v06ebDWOL
-c/hPVQFB94lEdiyjGO7RZfIe8KwcK48g7iv0LQU4+c9MoWM2ZsVM1AL2tHzokSeA
+// c/hPVQFB94lEdiyjGO7RZfIe8KwcK48g7iv0LQU4+c9MoWM2ZsVM1AL2tHzokSeA
-u64gDTW4K0Tzx1ab7KmOFXYUjbz/xWuReMt33EwDXAErKCjbVt2T55Qx8UoKzSh1
+// u64gDTW4K0Tzx1ab7KmOFXYUjbz/xWuReMt33EwDXAErKCjbVt2T55Qx8UoKzSh1
-tY0KDHdnYOzgsm2HIj2xcJqbeylYQvckNnoC
+// tY0KDHdnYOzgsm2HIj2xcJqbeylYQvckNnoC
------END CERTIFICATE-----`
+// -----END CERTIFICATE-----`
 
-	const keyPEM = `-----BEGIN RSA PRIVATE KEY-----
+// 	const keyPEM = `-----BEGIN RSA PRIVATE KEY-----
-Proc-Type: 4,ENCRYPTED
+// Proc-Type: 4,ENCRYPTED
-DEK-Info: AES-256-CBC,C16BF8745B2CDB53AC2B1D7609893AA0
+// DEK-Info: AES-256-CBC,C16BF8745B2CDB53AC2B1D7609893AA0
 
-O13z7Yq7butaJmMfg9wRis9YnIDPsp4coYI6Ud+JGcP7iXoy95QMhovKWx25o1ol
+// O13z7Yq7butaJmMfg9wRis9YnIDPsp4coYI6Ud+JGcP7iXoy95QMhovKWx25o1ol
-tvUTsrsG27fHGf9qG02KizApIVtO9c1e0swCWzFrKRQX0JDiZDmilb9xosBNNst1
+// tvUTsrsG27fHGf9qG02KizApIVtO9c1e0swCWzFrKRQX0JDiZDmilb9xosBNNst1
-BOzOTRZEwFGSOCKZRBfSXyqC93TvLJ3DO9IUnKIeGt7upipvg29b/Dur/fyCy2WV
+// BOzOTRZEwFGSOCKZRBfSXyqC93TvLJ3DO9IUnKIeGt7upipvg29b/Dur/fyCy2WV
-bLHXwUTDBm7j49yfoEyGkDjoB2QO9wgcgbacbnQJQ25fTFUwZpZJEJv6o1tRhoYM
+// bLHXwUTDBm7j49yfoEyGkDjoB2QO9wgcgbacbnQJQ25fTFUwZpZJEJv6o1tRhoYM
-ZMOhC9x1URmdHKN1+z2y5BrB6oNpParfeAMEvs/9FE6jJwYUR28Ql6Mhphfvr9W2
+// ZMOhC9x1URmdHKN1+z2y5BrB6oNpParfeAMEvs/9FE6jJwYUR28Ql6Mhphfvr9W2
-5Gxd3J65Ao9Vi2I5j5X6aBuNjyhXN3ScLjPG4lVZm9RU/uTPEt81pig/d5nSAjvF
+// 5Gxd3J65Ao9Vi2I5j5X6aBuNjyhXN3ScLjPG4lVZm9RU/uTPEt81pig/d5nSAjvF
-Nfc08NuG3cnMyJSE/xScJ4D+GtX8U969wO4oKPCR4E/NFyXPR730ppupDFG6hzPD
+// Nfc08NuG3cnMyJSE/xScJ4D+GtX8U969wO4oKPCR4E/NFyXPR730ppupDFG6hzPD
-PDmiszDtU438JAZ8AuFa1LkbyFnEW6KVD4h7VRr8YDjirCqnkgjNSI6dFY0NQ8H7
+// PDmiszDtU438JAZ8AuFa1LkbyFnEW6KVD4h7VRr8YDjirCqnkgjNSI6dFY0NQ8H7
-SyexB0lrceX6HZc+oNdAtkX3tYdzY3ExzUM5lSF1dkldnRbApLbqc4uuNIVXhXFM
+// SyexB0lrceX6HZc+oNdAtkX3tYdzY3ExzUM5lSF1dkldnRbApLbqc4uuNIVXhXFM
-dJnoPdKAzM6i+2EeVUxWNdafKDxnjVSHIHzHfIFJLQ4GS5rnz9keRFdyDjQL07tT
+// dJnoPdKAzM6i+2EeVUxWNdafKDxnjVSHIHzHfIFJLQ4GS5rnz9keRFdyDjQL07tT
-Lu9pPOmsadDXp7oSa81RgoCUfNZeR4jKpCk2BOft0L6ZSqwYFLcQHLIfJaGfn902
+// Lu9pPOmsadDXp7oSa81RgoCUfNZeR4jKpCk2BOft0L6ZSqwYFLcQHLIfJaGfn902
-TUOTxHt0KzEUYeYSrXC2a6cyvXAd1YI7lOgy60qG89VHyCc2v5Bs4c4FNUDC/+Dj
+// TUOTxHt0KzEUYeYSrXC2a6cyvXAd1YI7lOgy60qG89VHyCc2v5Bs4c4FNUDC/+Dj
-4ZwogaAbSNkLaE0q3sYQRPdxSqLftyX0KitAgE7oGtdzBfe1cdBoozw3U67NEMMT
+// 4ZwogaAbSNkLaE0q3sYQRPdxSqLftyX0KitAgE7oGtdzBfe1cdBoozw3U67NEMMT
-6qvk5j7RepPRSrapHtK5pMMdg5XpKFWcOXZ26VHVrDCj4JKdjVb4iyiQi94VveV0
+// 6qvk5j7RepPRSrapHtK5pMMdg5XpKFWcOXZ26VHVrDCj4JKdjVb4iyiQi94VveV0
-w9+KcOtyrM7/jbQlCWnXpsIkP8VA/RIgh7CBn/h4oF1sO8ywP25OGQ7VWAVq1R9D
+// w9+KcOtyrM7/jbQlCWnXpsIkP8VA/RIgh7CBn/h4oF1sO8ywP25OGQ7VWAVq1R9D
-8bl8GzIdR9PZpFyOxuIac4rPa8tkDeoXKs4cxoao7H/OZO9o9aTB7CJMTL9yv0Kb
+// 8bl8GzIdR9PZpFyOxuIac4rPa8tkDeoXKs4cxoao7H/OZO9o9aTB7CJMTL9yv0Kb
-ntWuYxQchE6syoGsOgdGyZhaw4JeFkasDUP5beyNY+278NkzgGTOIMMTXIX46woP
+// ntWuYxQchE6syoGsOgdGyZhaw4JeFkasDUP5beyNY+278NkzgGTOIMMTXIX46woP
-ehzHKGHXVGf7ZiSFF+zAHMXZRSwNVMkOYwlIoRg1IbvIRbAXqAR6xXQTCVzNG0SU
+// ehzHKGHXVGf7ZiSFF+zAHMXZRSwNVMkOYwlIoRg1IbvIRbAXqAR6xXQTCVzNG0SU
-cskojycBca1Cz3hDVIKYZd9beDhprVdr2a4K2nft2g2xRNjKPopsaqXx+VPibFUx
+// cskojycBca1Cz3hDVIKYZd9beDhprVdr2a4K2nft2g2xRNjKPopsaqXx+VPibFUx
-X7542eQ3eAlhkWUuXvt0q5a9WJdjJp9ODA0/d0akF6JQlEHIAyLfoUKB1HYwgUGG
+// X7542eQ3eAlhkWUuXvt0q5a9WJdjJp9ODA0/d0akF6JQlEHIAyLfoUKB1HYwgUGG
-6uRm651FDAab9U4cVC5PY1hfv/QwzpkNDkzgJAZ5SMOfZhq7IdBcqGd3lzPmq2FP
+// 6uRm651FDAab9U4cVC5PY1hfv/QwzpkNDkzgJAZ5SMOfZhq7IdBcqGd3lzPmq2FP
-Vy1LVZIl3eM+9uJx5TLsBHH6NhMwtNhFCNa/5ksodQYlTvR8IrrgWlYg4EL69vjS
+// Vy1LVZIl3eM+9uJx5TLsBHH6NhMwtNhFCNa/5ksodQYlTvR8IrrgWlYg4EL69vjS
-yt6HhhEN3lFCWvrQXQMp93UklbTlpVt6qcDXiC7HYbs3+EINargRd5Z+xL5i5vkN
+// yt6HhhEN3lFCWvrQXQMp93UklbTlpVt6qcDXiC7HYbs3+EINargRd5Z+xL5i5vkN
-f9k7s0xqhloWNPZcyOXMrox8L81WOY+sP4mVlGcfDRLdEJ8X2ofJpOAcwYCnjsKd
+// f9k7s0xqhloWNPZcyOXMrox8L81WOY+sP4mVlGcfDRLdEJ8X2ofJpOAcwYCnjsKd
-uEGsi+l2fTj/F+eZLE6sYoMprgJrbfeqtRWFguUgTn7s5hfU0tZ46al5d0vz8fWK
+// uEGsi+l2fTj/F+eZLE6sYoMprgJrbfeqtRWFguUgTn7s5hfU0tZ46al5d0vz8fWK
------END RSA PRIVATE KEY-----`
+// -----END RSA PRIVATE KEY-----`
 
-	passphrase = "test"
+// 	passphrase = "test"
 
-	certFile, err = createTmpFile(certPEM)
+// 	certFile, err = createTmpFile(certPEM)
-	if err != nil {
+// 	if err != nil {
-		return
+// 		return
-	}
+// 	}
-	keyFile, err = createTmpFile(keyPEM)
+// 	keyFile, err = createTmpFile(keyPEM)
-	return
+// 	return
-}
+// }
 
 func TestAuthMechs(t *testing.T) {
 	s := session{}
@@ -966,7 +967,7 @@ func TestCmdAUTH(t *testing.T) {
 	cmdCode(t, conn, "AUTH", "502")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdAUTHOptional(t *testing.T) {
@@ -1007,7 +1008,7 @@ func TestCmdAUTHOptional(t *testing.T) {
 	cmdCode(t, conn, "*", "501")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdAUTHRequired(t *testing.T) {
@@ -1056,7 +1057,7 @@ func TestCmdAUTHRequired(t *testing.T) {
 	cmdCode(t, conn, "AUTH PLAIN", "504")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdAUTHLOGIN(t *testing.T) {
@@ -1113,7 +1114,7 @@ func TestCmdAUTHLOGIN(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdAUTHLOGINFast(t *testing.T) {
@@ -1165,7 +1166,7 @@ func TestCmdAUTHLOGINFast(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdAUTHPLAIN(t *testing.T) {
@@ -1224,7 +1225,7 @@ func TestCmdAUTHPLAIN(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdAUTHPLAINEmpty(t *testing.T) {
@@ -1283,7 +1284,7 @@ func TestCmdAUTHPLAINEmpty(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdAUTHPLAINFast(t *testing.T) {
@@ -1335,7 +1336,7 @@ func TestCmdAUTHPLAINFast(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 func TestCmdAUTHPLAINFastAndEmpty(t *testing.T) {
@@ -1387,7 +1388,7 @@ func TestCmdAUTHPLAINFastAndEmpty(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 // makeCRAMMD5Response is a helper function to create the CRAM-MD5 hash.
@@ -1457,7 +1458,7 @@ func TestCmdAUTHCRAMMD5(t *testing.T) {
 	cmdCode(t, conn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, conn, "QUIT", "221")
-	conn.Close()
+	_ = conn.Close()
 }
 
 func TestCmdAUTHCRAMMD5WithTLS(t *testing.T) {
@@ -1523,7 +1524,7 @@ func TestCmdAUTHCRAMMD5WithTLS(t *testing.T) {
 	cmdCode(t, tlsConn, "AUTH CRAM-MD5", "503")
 
 	cmdCode(t, tlsConn, "QUIT", "221")
-	tlsConn.Close()
+	_ = tlsConn.Close()
 }
 
 // Benchmark the mail handling without the network stack introducing latency.
@@ -1540,17 +1541,17 @@ func BenchmarkReceive(b *testing.B) {
 
 	// Benchmark a full mail transaction.
 	for i := 0; i < b.N; i++ {
-		fmt.Fprintf(clientConn, "%s\r\n", "HELO host.example.com")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "HELO host.example.com")
 		_, _ = reader.ReadString('\n')
-		fmt.Fprintf(clientConn, "%s\r\n", "MAIL FROM:<sender@example.com>")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "MAIL FROM:<sender@example.com>")
 		_, _ = reader.ReadString('\n')
-		fmt.Fprintf(clientConn, "%s\r\n", "RCPT TO:<recipient@example.com>")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "RCPT TO:<recipient@example.com>")
 		_, _ = reader.ReadString('\n')
-		fmt.Fprintf(clientConn, "%s\r\n", "DATA")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "DATA")
 		_, _ = reader.ReadString('\n')
-		fmt.Fprintf(clientConn, "%s\r\n", "Test message.\r\n.")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "Test message.\r\n.")
 		_, _ = reader.ReadString('\n')
-		fmt.Fprintf(clientConn, "%s\r\n", "QUIT")
+		_, _ = fmt.Fprintf(clientConn, "%s\r\n", "QUIT")
 		_, _ = reader.ReadString('\n')
 	}
 }
@@ -1589,11 +1590,11 @@ func TestCmdShutdown(t *testing.T) {
 	cmdCode(t, conn, "QUIT", "221")
 
 	// connection should now be closed
-	fmt.Fprintf(conn, "%s\r\n", "HELO host.example.com")
+	_, _ = fmt.Fprintf(conn, "%s\r\n", "HELO host.example.com")
 	_, err := bufio.NewReader(conn).ReadString('\n')
 	if err != io.EOF {
 		t.Errorf("Expected connection to be closed\n")
 	}
 
-	conn.Close()
+	_ = conn.Close()
 }

internal/spamassassin/postmark/postmark.go

@@ -59,7 +59,7 @@ func Check(email []byte, timeout int) (Response, error) {
 		return r, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	err = json.NewDecoder(resp.Body).Decode(&r)
 

internal/spamassassin/spamc/spamc.go

@@ -70,21 +70,22 @@ type Result struct {
 
 // dial connects to spamd through TCP or a Unix socket.
 func (c *Client) dial() (connection, error) {
-	if c.net == "tcp" {
+	switch c.net {
+	case "tcp":
 		tcpAddr, err := net.ResolveTCPAddr("tcp", c.addr)
 		if err != nil {
 			return nil, err
 		}
 		return net.DialTCP("tcp", nil, tcpAddr)
-	} else if c.net == "unix" {
+	case "unix":
 		unixAddr, err := net.ResolveUnixAddr("unix", c.addr)
 		if err != nil {
 			return nil, err
 		}
 		return net.DialUnix("unix", nil, unixAddr)
+	default:
+		return nil, fmt.Errorf("unsupported network type: %s", c.net)
 	}
-
-	panic("Client.net must be either \"tcp\" or \"unix\"")
 }
 
 // Report checks if message is spam or not, and returns score plus report
@@ -103,7 +104,7 @@ func (c *Client) report(email []byte) ([]string, error) {
 		return nil, err
 	}
 
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	if err := conn.SetDeadline(time.Now().Add(time.Duration(c.timeout) * time.Second)); err != nil {
 		return nil, err
@@ -221,7 +222,7 @@ func (c *Client) Ping() error {
 	if err != nil {
 		return err
 	}
-	defer conn.Close()
+	defer func() { _ = conn.Close() }()
 
 	if err := conn.SetDeadline(time.Now().Add(time.Duration(c.timeout) * time.Second)); err != nil {
 		return err

internal/storage/database.go

@@ -27,7 +27,6 @@ import (
 
 var (
 	db           *sql.DB
-	dbFile       string
 	sqlDriver    string
 	dbLastAction time.Time
 
@@ -139,7 +138,6 @@ func InitDB() error {
 
 	LoadTagFilters()
 
-	dbFile = p
 	dbLastAction = time.Now()
 
 	sigs := make(chan os.Signal, 1)

internal/storage/messages.go

@@ -86,7 +86,7 @@ func Store(body *[]byte, username *string) (string, error) {
 	}
 
 	// roll back if it fails
-	defer tx.Rollback()
+	defer func() { _ = tx.Rollback() }()
 
 	subject := env.GetHeader("Subject")
 	size := uint64(len(*body))
@@ -118,8 +118,6 @@ func Store(body *[]byte, username *string) (string, error) {
 		} else {
 			_, err = tx.Exec(fmt.Sprintf(`INSERT INTO %s (ID, Email, Compressed) VALUES(?, ?, 1)`, tenant("mailbox_data")), id, compressed) // #nosec
 		}
-
-		compressed = nil
 	} else {
 		// insert uncompressed raw message
 		_, err = tx.Exec(fmt.Sprintf(`INSERT INTO %s (ID, Email, Compressed) VALUES(?, ?, 0)`, tenant("mailbox_data")), id, string(*body)) // #nosec
@@ -639,7 +637,7 @@ func DeleteMessages(ids []string) error {
 	if err != nil {
 		return err
 	}
-	defer rows.Close()
+	defer func() { _ = rows.Close() }()
 
 	toDelete := []string{}
 	var totalSize uint64
@@ -738,7 +736,7 @@ func DeleteAllMessages() error {
 	}
 
 	// roll back if it fails
-	defer tx.Rollback()
+	defer func() { _ = tx.Rollback() }()
 
 	tables := []string{"mailbox", "mailbox_data", "tags", "message_tags"}
 

internal/storage/reindex.go

@@ -114,7 +114,7 @@ func ReindexAll() {
 		}
 
 		// roll back if it fails
-		defer tx.Rollback()
+		defer func() { _ = tx.Rollback() }()
 
 		// insert mail summary data
 		for _, u := range updates {

internal/storage/search.go

@@ -193,7 +193,7 @@ func DeleteSearch(search, timezone string) error {
 		}
 
 		// roll back if it fails
-		defer tx.Rollback()
+		defer func() { _ = tx.Rollback() }()
 
 		for _, ids := range chunks {
 			delIDs := make([]interface{}, len(ids))

internal/tools/fs.go

@@ -8,7 +8,7 @@ import (
 // IsFile returns whether a file exists and is readable
 func IsFile(path string) bool {
 	f, err := os.Open(filepath.Clean(path))
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 	return err == nil
 }
 

internal/tools/listunsubscribeparser.go

@@ -27,7 +27,7 @@ func ListUnsubscribeParser(v string) ([]string, error) {
 	comments := reComments.FindAllStringSubmatch(v, -1)
 	for _, c := range comments {
 		// strip comments
-		v = strings.Replace(v, c[0], "", -1)
+		v = strings.ReplaceAll(v, c[0], "")
 		v = strings.TrimSpace(v)
 	}
 

internal/updater/targz.go

@@ -115,7 +115,7 @@ func extract(filePath string, directory string) error {
 	if err != nil {
 		return err
 	}
-	defer gzipReader.Close()
+	defer func() { _ = gzipReader.Close() }()
 
 	tarReader := tar.NewReader(gzipReader)
 

internal/updater/unzip.go

@@ -19,7 +19,7 @@ func Unzip(src string, dest string) ([]string, error) {
 	if err != nil {
 		return filenames, err
 	}
-	defer r.Close()
+	defer func() { _ = r.Close() }()
 
 	for _, f := range r.File {
 

internal/updater/updater.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -70,7 +71,7 @@ func GithubLatest(repo, name string) (string, string, string, error) {
 		return "", "", "", err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	body, err := io.ReadAll(resp.Body)
 
@@ -119,7 +120,7 @@ func GithubLatest(repo, name string) (string, string, string, error) {
 
 	if len(allReleases) == 0 {
 		// no releases with suitable assets found
-		return "", "", "", fmt.Errorf("No binary releases found")
+		return "", "", "", errors.New("no binary releases found")
 	}
 
 	var latestRelease = Release{}
@@ -149,11 +150,11 @@ func GithubUpdate(repo, appName, currentVersion string) (string, error) {
 	}
 
 	if ver == currentVersion {
-		return "", fmt.Errorf("No new release found")
+		return "", errors.New("no new release found")
 	}
 
 	if semver.Compare(ver, currentVersion) < 1 {
-		return "", fmt.Errorf("No newer releases found (latest %s)", ver)
+		return "", fmt.Errorf("no newer releases found (latest %s)", ver)
 	}
 
 	tmpDir := getTempDir()
@@ -212,7 +213,7 @@ func downloadToFile(url, fileName string) error {
 	if err != nil {
 		return err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	// Create the file
 	out, err := os.Create(filepath.Clean(fileName))

sendmail/cmd/cmd.go

@@ -121,14 +121,14 @@ func Run() {
 	// handles `sendmail -bs`
 	// telnet directly to SMTP
 	if UseB && UseS {
-		var caller telnet.Caller = telnet.StandardCaller
+		var caller = telnet.StandardCaller
-
+		switch isSocket {
-		if isSocket {
+		case true:
 			if err := telnet.DialToAndCallUnix(socketAddr, caller); err != nil {
 				fmt.Println(err)
 				os.Exit(1)
 			}
-		} else {
+		default:
 			if err := telnet.DialToAndCall(SMTPAddr, caller); err != nil {
 				fmt.Println(err)
 				os.Exit(1)

server/apiv1/api.go

@@ -18,7 +18,7 @@ func fourOFour(w http.ResponseWriter) {
 	w.Header().Set("Content-Security-Policy", config.ContentSecurityPolicy)
 	w.WriteHeader(http.StatusNotFound)
 	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprint(w, "404 page not found")
+	_, _ = fmt.Fprint(w, "404 page not found")
 }
 
 // HTTPError returns a basic error message (400 response)
@@ -27,7 +27,7 @@ func httpError(w http.ResponseWriter, msg string) {
 	w.Header().Set("Content-Security-Policy", config.ContentSecurityPolicy)
 	w.WriteHeader(http.StatusBadRequest)
 	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprint(w, msg)
+	_, _ = fmt.Fprint(w, msg)
 }
 
 // httpJSONError returns a basic error message (400 response) in JSON format

server/apiv1/message.go

@@ -49,7 +49,7 @@ func GetMessage(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}
@@ -108,7 +108,7 @@ func GetHeaders(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}
@@ -179,7 +179,7 @@ func DownloadAttachment(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}
@@ -238,7 +238,7 @@ func DownloadRaw(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}

server/apiv1/other.go

@@ -210,7 +210,7 @@ func SpamAssassinCheck(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}

server/apiv1/testing.go

@@ -67,7 +67,7 @@ func GetMessageHTML(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}
@@ -75,12 +75,12 @@ func GetMessageHTML(w http.ResponseWriter, r *http.Request) {
 	msg, err := storage.GetMessage(id)
 	if err != nil {
 		w.WriteHeader(404)
-		fmt.Fprint(w, "Message not found")
+		_, _ = fmt.Fprint(w, "Message not found")
 		return
 	}
 	if msg.HTML == "" {
 		w.WriteHeader(404)
-		fmt.Fprint(w, "This message does not contain a HTML part")
+		_, _ = fmt.Fprint(w, "This message does not contain a HTML part")
 		return
 	}
 
@@ -161,7 +161,7 @@ func GetMessageText(w http.ResponseWriter, r *http.Request) {
 		id, err = storage.LatestID(r)
 		if err != nil {
 			w.WriteHeader(404)
-			fmt.Fprint(w, err.Error())
+			_, _ = fmt.Fprint(w, err.Error())
 			return
 		}
 	}
@@ -169,7 +169,7 @@ func GetMessageText(w http.ResponseWriter, r *http.Request) {
 	msg, err := storage.GetMessage(id)
 	if err != nil {
 		w.WriteHeader(404)
-		fmt.Fprint(w, "Message not found")
+		_, _ = fmt.Fprint(w, "Message not found")
 		return
 	}
 

server/handlers/messages.go

@@ -39,5 +39,5 @@ func RedirectToLatestMessage(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	http.Redirect(w, r, uri, 302)
+	http.Redirect(w, r, uri, http.StatusFound)
 }

server/handlers/proxy.go

@@ -60,7 +60,8 @@ func ProxyHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
+
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		logger.Log().Warnf("[proxy] %s", err.Error())
@@ -141,7 +142,7 @@ func absoluteURL(link, baseURL string) (string, error) {
 
 	// ensure link is HTTP(S)
 	if result.Scheme != "http" && result.Scheme != "https" {
-		return link, fmt.Errorf("Invalid URL: %s", result.String())
+		return link, fmt.Errorf("invalid URL: %s", result.String())
 	}
 
 	return result.String(), nil
@@ -153,5 +154,5 @@ func httpError(w http.ResponseWriter, msg string) {
 	w.Header().Set("Content-Security-Policy", config.ContentSecurityPolicy)
 	w.WriteHeader(http.StatusBadRequest)
 	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprint(w, msg)
+	_, _ = fmt.Fprint(w, msg)
 }

server/server.go

@@ -290,8 +290,9 @@ func middleWareFunc(fn http.HandlerFunc) http.HandlerFunc {
 		}
 
 		// Check basic authentication headers if configured.
-		// OPTIONS requests are skipped if CORS is enabled, since browsers omit credentials for preflight.
+		// OPTIONS requests are skipped if CORS is enabled, since browsers omit credentials for preflight checks.
-		if !(AccessControlAllowOrigin != "" && r.Method == http.MethodOptions) && auth.UICredentials != nil {
+		isCORSOptionsRequest := AccessControlAllowOrigin != "" && r.Method == http.MethodOptions
+		if !isCORSOptionsRequest && auth.UICredentials != nil {
 			user, pass, ok := r.BasicAuth()
 
 			if !ok {
@@ -312,7 +313,7 @@ func middleWareFunc(fn http.HandlerFunc) http.HandlerFunc {
 
 		w.Header().Set("Content-Encoding", "gzip")
 		gz := gzip.NewWriter(w)
-		defer gz.Close()
+		defer func() { _ = gz.Close() }()
 		gzr := gzipResponseWriter{Writer: gz, ResponseWriter: w}
 		fn(gzr, r)
 	}

server/server_test.go

@@ -345,7 +345,9 @@ func TestSendAPIAuthMiddleware(t *testing.T) {
 
 		// Set up UI auth that would normally block requests
 		testHash, _ := bcrypt.GenerateFromPassword([]byte("testpass"), bcrypt.DefaultCost)
-		auth.SetUIAuth("testuser:" + string(testHash))
+		if err := auth.SetUIAuth("testuser:" + string(testHash)); err != nil {
+			t.Fatalf("Failed to set UI auth: %s", err.Error())
+		}
 
 		r := apiRoutes()
 		ts := httptest.NewServer(r)
@@ -374,11 +376,15 @@ func TestSendAPIAuthMiddleware(t *testing.T) {
 
 		// Set up UI auth
 		uiHash, _ := bcrypt.GenerateFromPassword([]byte("uipass"), bcrypt.DefaultCost)
-		auth.SetUIAuth("uiuser:" + string(uiHash))
+		if err := auth.SetUIAuth("uiuser:" + string(uiHash)); err != nil {
+			t.Fatalf("Failed to set UI auth: %s", err.Error())
+		}
 
 		// Set up dedicated Send API auth
 		sendHash, _ := bcrypt.GenerateFromPassword([]byte("sendpass"), bcrypt.DefaultCost)
-		auth.SetSendAPIAuth("senduser:" + string(sendHash))
+		if err := auth.SetSendAPIAuth("senduser:" + string(sendHash)); err != nil {
+			t.Fatalf("Failed to set Send API auth: %s", err.Error())
+		}
 
 		r := apiRoutes()
 		ts := httptest.NewServer(r)
@@ -421,7 +427,9 @@ func TestSendAPIAuthMiddleware(t *testing.T) {
 
 		// Set up only UI auth
 		uiHash, _ := bcrypt.GenerateFromPassword([]byte("uipass"), bcrypt.DefaultCost)
-		auth.SetUIAuth("uiuser:" + string(uiHash))
+		if err := auth.SetUIAuth("uiuser:" + string(uiHash)); err != nil {
+			t.Fatalf("Failed to set UI auth: %s", err.Error())
+		}
 
 		r := apiRoutes()
 		ts := httptest.NewServer(r)
@@ -455,9 +463,14 @@ func TestSendAPIAuthMiddleware(t *testing.T) {
 
 		// Set up UI auth and Send API auth
 		uiHash, _ := bcrypt.GenerateFromPassword([]byte("uipass"), bcrypt.DefaultCost)
-		auth.SetUIAuth("uiuser:" + string(uiHash))
+		if err := auth.SetUIAuth("uiuser:" + string(uiHash)); err != nil {
+			t.Fatalf("Failed to set UI auth: %s", err.Error())
+		}
+
 		sendHash, _ := bcrypt.GenerateFromPassword([]byte("sendpass"), bcrypt.DefaultCost)
-		auth.SetSendAPIAuth("senduser:" + string(sendHash))
+		if err := auth.SetSendAPIAuth("senduser:" + string(sendHash)); err != nil {
+			t.Fatalf("Failed to set Send API auth: %s", err.Error())
+		}
 
 		r := apiRoutes()
 		ts := httptest.NewServer(r)
@@ -604,7 +617,7 @@ func clientGet(url string) ([]byte, error) {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	data, err := io.ReadAll(resp.Body)
 
@@ -625,7 +638,7 @@ func clientDelete(url, body string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)
@@ -650,7 +663,7 @@ func clientPut(url, body string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)
@@ -675,7 +688,7 @@ func clientPost(url, body string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)
@@ -702,7 +715,7 @@ func clientPostWithAuth(url, body, username, password string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)
@@ -728,7 +741,7 @@ func clientGetWithAuth(url, username, password string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("%s returned status %d", url, resp.StatusCode)

server/webhook/webhook.go

@@ -22,7 +22,7 @@ var (
 )
 
 // Send will post the MessageSummary to a webhook (if configured)
-func Send(msg interface{}) {
+func Send(msg any) {
 	if config.WebhookURL == "" {
 		return
 	}
@@ -70,7 +70,7 @@ func Send(msg interface{}) {
 				return
 			}
 
-			defer resp.Body.Close()
+			_ = resp.Body.Close()
 		})
 	}()
 }