chore: many small lint/perf fixes (#491)

Signed-off-by: James Hillyerd <james@hillyerd.com>

cmd/client/main.go

@@ -5,8 +5,10 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"net"
 	"os"
 	"regexp"
+	"strconv"
 
 	"github.com/google/subcommands"
 )
@@ -68,7 +70,8 @@ func main() {
 }
 
 func baseURL() string {
-	return fmt.Sprintf("http://%s:%v", *host, *port)
+	return fmt.Sprintf("http://%s",
+		net.JoinHostPort(*host, strconv.FormatUint(uint64(*port), 10)))
 }
 
 func fatal(msg string, err error) subcommands.ExitStatus {

cmd/inbucket/main.go

@@ -162,7 +162,7 @@ signalLoop:
 }
 
 // openLog configures zerolog output, returns func to close logfile.
-func openLog(level string, logfile string, json bool) (close func(), err error) {
+func openLog(level string, logfile string, json bool) (closeLog func(), err error) {
 	switch level {
 	case "debug":
 		zerolog.SetGlobalLevel(zerolog.DebugLevel)
@@ -175,7 +175,8 @@ func openLog(level string, logfile string, json bool) (close func(), err error)
 	default:
 		return nil, fmt.Errorf("log level %q not one of: debug, info, warn, error", level)
 	}
-	close = func() {}
+
+	closeLog = func() {}
 	var w io.Writer
 	color := runtime.GOOS != "windows"
 	switch logfile {
@@ -191,21 +192,24 @@ func openLog(level string, logfile string, json bool) (close func(), err error)
 		bw := bufio.NewWriter(logf)
 		w = bw
 		color = false
-		close = func() {
+		closeLog = func() {
 			_ = bw.Flush()
 			_ = logf.Close()
 		}
 	}
+
 	w = zerolog.SyncWriter(w)
 	if json {
 		log.Logger = log.Output(w)
-		return close, nil
+		return closeLog, nil
 	}
+
 	log.Logger = log.Output(zerolog.ConsoleWriter{
 		Out:     w,
 		NoColor: !color,
 	})
-	return close, nil
+
+	return closeLog, nil
 }
 
 // removePIDFile removes the PID file if created.

pkg/policy/address.go

@@ -285,7 +285,7 @@ LOOP:
 				return
 			}
 			inCharQuote = false
-		case bytes.IndexByte([]byte("!#$%&'*+-/=?^_`{|}~"), c) >= 0:
+		case strings.IndexByte("!#$%&'*+-/=?^_`{|}~", c) >= 0:
 			// These specials can be used unquoted.
 			err = buf.WriteByte(c)
 			if err != nil {
@@ -378,7 +378,7 @@ func parseMailboxName(localPart string) (result string, err error) {
 		switch {
 		case 'a' <= c && c <= 'z':
 		case '0' <= c && c <= '9':
-		case bytes.IndexByte([]byte("!#$%&'*+-=/?^_`.{|}~"), c) >= 0:
+		case strings.IndexByte("!#$%&'*+-=/?^_`.{|}~", c) >= 0:
 		default:
 			invalid = append(invalid, c)
 		}

pkg/policy/address_test.go

@@ -283,24 +283,18 @@ func TestExtractMailboxValid(t *testing.T) {
 	for _, tc := range testTable {
 		if result, err := localPolicy.ExtractMailbox(tc.input); err != nil {
 			t.Errorf("Error while parsing with local naming %q: %v", tc.input, err)
-		} else {
-			if result != tc.local {
-				t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.local, result)
-			}
+		} else if result != tc.local {
+			t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.local, result)
 		}
 		if result, err := fullPolicy.ExtractMailbox(tc.input); err != nil {
 			t.Errorf("Error while parsing with full naming %q: %v", tc.input, err)
-		} else {
-			if result != tc.full {
-				t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.full, result)
-			}
+		} else if result != tc.full {
+			t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.full, result)
 		}
 		if result, err := domainPolicy.ExtractMailbox(tc.input); tc.domain != "" && err != nil {
 			t.Errorf("Error while parsing with domain naming %q: %v", tc.input, err)
-		} else {
-			if result != tc.domain {
-				t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.domain, result)
-			}
+		} else if result != tc.domain {
+			t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.domain, result)
 		}
 	}
 }
@@ -327,10 +321,8 @@ func TestExtractDomainMailboxValid(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			if result, err := domainPolicy.ExtractMailbox(tc.input); tc.domain != "" && err != nil {
 				t.Errorf("Error while parsing with domain naming %q: %v", tc.input, err)
-			} else {
-				if result != tc.domain {
-					t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.domain, result)
-				}
+			} else if result != tc.domain {
+				t.Errorf("Parsing %q, expected %q, got %q", tc.input, tc.domain, result)
 			}
 		})
 	}

pkg/rest/testutils_test.go

@@ -122,9 +122,10 @@ func getDecodedPath(o interface{}, path ...string) (interface{}, string) {
 	if o == nil {
 		return nil, " is nil"
 	}
-	key := path[0]
-	present := false
+
+	var present bool
 	var val interface{}
+	key := path[0]
 	if key[0] == '[' {
 		// Expecting slice.
 		index, err := strconv.Atoi(strings.Trim(key, "[]"))
@@ -147,12 +148,15 @@ func getDecodedPath(o interface{}, path ...string) (interface{}, string) {
 		}
 		val, present = omap[key]
 	}
+
 	if !present {
 		return nil, "/" + key + " is missing"
 	}
+
 	result, msg := getDecodedPath(val, path[1:]...)
 	if msg != "" {
 		return nil, "/" + key + msg
 	}
+
 	return result, ""
 }

pkg/server/pop3/handler.go

@@ -134,48 +134,46 @@ func (s *Server) startSession(id int, conn net.Conn) {
 		line, err := ssn.readLine()
 		ssn.logger.Debug().Msgf("read %s", line)
 		if err == nil {
-			if cmd, arg, ok := ssn.parseCmd(line); ok {
-				// Check against valid SMTP commands
-				if cmd == "" {
-					ssn.send("-ERR Speak up")
-					continue
+			cmd, arg := ssn.parseCmd(line)
+			// Commands we handle in any state
+			if cmd == "CAPA" {
+				// List our capabilities per RFC2449
+				ssn.send("+OK Capability list follows")
+				ssn.send("TOP")
+				ssn.send("USER")
+				ssn.send("UIDL")
+				ssn.send("IMPLEMENTATION Inbucket")
+				if s.tlsConfig != nil && s.tlsState == nil && !s.config.ForceTLS {
+					ssn.send("STLS")
 				}
-				if !commands[cmd] {
-					ssn.send(fmt.Sprintf("-ERR Syntax error, %v command unrecognized", cmd))
-					ssn.logger.Warn().Msgf("Unrecognized command: %v", cmd)
-					continue
-				}
-
-				// Commands we handle in any state
-				switch cmd {
-				case "CAPA":
-					// List our capabilities per RFC2449
-					ssn.send("+OK Capability list follows")
-					ssn.send("TOP")
-					ssn.send("USER")
-					ssn.send("UIDL")
-					ssn.send("IMPLEMENTATION Inbucket")
-					if s.tlsConfig != nil && s.tlsState == nil && !s.config.ForceTLS {
-						ssn.send("STLS")
-					}
-					ssn.send(".")
-					continue
-				}
-
-				// Send command to handler for current state
-				switch ssn.state {
-				case AUTHORIZATION:
-					ssn.authorizationHandler(cmd, arg)
-					continue
-				case TRANSACTION:
-					ssn.transactionHandler(cmd, arg)
-					continue
-				}
-				ssn.logger.Error().Msgf("Session entered unexpected state %v", ssn.state)
-				break
-			} else {
-				ssn.send("-ERR Syntax error, command garbled")
+				ssn.send(".")
+				continue
 			}
+
+			// Check against valid SMTP commands
+			if cmd == "" {
+				ssn.send("-ERR Speak up")
+				continue
+			}
+
+			if !commands[cmd] {
+				ssn.send(fmt.Sprintf("-ERR Syntax error, %v command unrecognized", cmd))
+				ssn.logger.Warn().Msgf("Unrecognized command: %v", cmd)
+				continue
+			}
+
+			// Send command to handler for current state
+			switch ssn.state {
+			case AUTHORIZATION:
+				ssn.authorizationHandler(cmd, arg)
+				continue
+			case TRANSACTION:
+				ssn.transactionHandler(cmd, arg)
+				continue
+			}
+
+			ssn.logger.Error().Msgf("Session entered unexpected state %v", ssn.state)
+			break
 		} else {
 			// readLine() returned an error
 			if err == io.EOF {
@@ -631,14 +629,14 @@ func (s *Session) readLine() (line string, err error) {
 	return line, nil
 }
 
-func (s *Session) parseCmd(line string) (cmd string, args []string, ok bool) {
+func (s *Session) parseCmd(line string) (cmd string, args []string) {
 	line = strings.TrimRight(line, "\r\n")
 	if line == "" {
-		return "", nil, true
+		return "", nil
 	}
 
 	words := strings.Split(line, " ")
-	return strings.ToUpper(words[0]), words[1:], true
+	return strings.ToUpper(words[0]), words[1:]
 }
 
 func (s *Session) reset() {

pkg/server/smtp/handler.go

@@ -173,13 +173,13 @@ func (s *Server) startSession(id int, conn net.Conn, logger zerolog.Logger) {
 		}
 		line, err := ssn.readLine()
 		if err == nil {
-			//Handle LOGIN/PASSWORD states here, because they don't expect a command
+			// Handle LOGIN/PASSWORD states here, because they don't expect a command.
 			switch ssn.state {
 			case LOGIN:
-				ssn.loginHandler(line)
+				ssn.loginHandler()
 				continue
 			case PASSWORD:
-				ssn.passwordHandler(line)
+				ssn.passwordHandler()
 				continue
 			}
 
@@ -312,13 +312,13 @@ func parseHelloArgument(arg string) (string, error) {
 	return domain, nil
 }
 
-func (s *Session) loginHandler(line string) {
+func (s *Session) loginHandler() {
 	// Content and length of username is ignored.
 	s.send(fmt.Sprintf("334 %v", passwordChallenge))
 	s.enterState(PASSWORD)
 }
 
-func (s *Session) passwordHandler(line string) {
+func (s *Session) passwordHandler() {
 	// Content and length of password is ignored.
 	s.send("235 Authentication successful")
 	s.enterState(READY)

pkg/storage/file/mbox.go

@@ -112,6 +112,8 @@ func (mb *mbox) readIndex() error {
 		log.Debug().Str("module", "storage").Str("path", mb.indexPath).
 			Msg("Index does not yet exist")
 		mb.indexLoaded = true
+
+		//lint:ignore nilerr missing mailboxes are considered empty.
 		return nil
 	}
 	file, err := os.Open(mb.indexPath)

pkg/webui/sanitize/html.go

@@ -39,7 +39,7 @@ func sanitizeStyleTags(input string) (string, error) {
 
 func styleTagFilter(w io.Writer, r io.Reader) error {
 	bw := bufio.NewWriter(w)
-	b := make([]byte, 256)
+	b := make([]byte, 0, 256)
 	z := html.NewTokenizer(r)
 	for {
 		b = b[:0]