lint: homogenize operations and minor fixes (gocritic)

Apply GoDoc comment policy (comments for humans should have a space
after the //; machine-readable comments shouldn't)

Use strings.ReplaceAll instead of strings.Replace when appropriate

Remove if/else chains by replacing them with switches

Use short assignment/increment notation

Replace single case switches with if statements

Combine else and if when appropriate

Signed-off-by: Moritz Poldrack <moritz@poldrack.dev>
Acked-by: Robin Jarry <robin@jarry.cc>

aerc.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"os"
 	"sort"
@@ -59,19 +60,20 @@ func execCommand(aerc *widgets.Aerc, ui *libui.UI, cmd []string) error {
 	cmds := getCommands(aerc.SelectedTabContent())
 	for i, set := range cmds {
 		err := set.ExecuteCommand(aerc, cmd)
-		if _, ok := err.(commands.NoSuchCommand); ok {
+		if err != nil {
-			if i == len(cmds)-1 {
+			if errors.As(err, new(commands.NoSuchCommand)) {
-				return err
+				if i == len(cmds)-1 {
+					return err
+				}
+				continue
+			}
+			if errors.As(err, new(commands.ErrorExit)) {
+				ui.Exit()
+				return nil
 			}
-			continue
-		} else if _, ok := err.(commands.ErrorExit); ok {
-			ui.Exit()
-			return nil
-		} else if err != nil {
 			return err
-		} else {
-			break
 		}
+		break
 	}
 	return nil
 }
@@ -123,8 +125,7 @@ func main() {
 		return
 	}
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'v' {
-		case 'v':
 			fmt.Println("aerc " + Version)
 			return
 		}
@@ -153,7 +154,7 @@ func main() {
 	conf, err := config.LoadConfigFromFile(nil)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Failed to load config: %v\n", err)
-		os.Exit(1)
+		os.Exit(1) //nolint:gocritic // PanicHandler does not need to run as it's not a panic
 	}
 
 	var (

commands/account/clear.go

@@ -39,8 +39,7 @@ func (Clear) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 's' {
-		case 's':
 			clearSelected = true
 		}
 	}

commands/account/import-mbox.go

@@ -135,8 +135,7 @@ func (ImportMbox) Execute(aerc *widgets.Aerc, args []string) error {
 			func(option string, err error) {
 				aerc.CloseDialog()
 				aerc.Invalidate()
-				switch option {
+				if option == "Yes" {
-				case "Yes":
 					go importFolder()
 				}
 			},

commands/account/recover.go

@@ -36,9 +36,10 @@ func (Recover) Complete(aerc *widgets.Aerc, args []string) []string {
 	if len(args) == 0 {
 		return files
 	}
-	if args[0] == "-" {
+	switch args[0] {
+	case "-":
 		return []string{"-f"}
-	} else if args[0] == "-f" {
+	case "-f":
 		if len(args) == 1 {
 			for i, file := range files {
 				files[i] = args[0] + " " + file
@@ -49,7 +50,7 @@ func (Recover) Complete(aerc *widgets.Aerc, args []string) []string {
 			return commands.FilterList(files, args[1], args[0]+" ",
 				aerc.SelectedAccountUiConfig().FuzzyComplete)
 		}
-	} else {
+	default:
 		// only accepts one file to recover
 		return commands.FilterList(files, args[0], "", aerc.SelectedAccountUiConfig().FuzzyComplete)
 	}
@@ -68,8 +69,7 @@ func (Recover) Execute(aerc *widgets.Aerc, args []string) error {
 		return err
 	}
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'f' {
-		case 'f':
 			force = true
 		}
 	}

commands/account/rmdir.go

@@ -37,8 +37,7 @@ func (RemoveDir) Execute(aerc *widgets.Aerc, args []string) error {
 		return err
 	}
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'f' {
-		case 'f':
 			force = true
 		}
 	}

commands/compose/header.go

@@ -50,8 +50,7 @@ func (Header) Execute(aerc *widgets.Aerc, args []string) error {
 
 	var force bool = false
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'f' {
-		case 'f':
 			force = true
 		}
 	}

commands/compose/send.go

@@ -250,12 +250,13 @@ func parseScheme(uri *url.URL) (scheme string, auth string, err error) {
 	auth = "plain"
 	if uri.Scheme != "" {
 		parts := strings.Split(uri.Scheme, "+")
-		if len(parts) == 1 {
+		switch len(parts) {
+		case 1:
 			scheme = parts[0]
-		} else if len(parts) == 2 {
+		case 2:
 			scheme = parts[0]
 			auth = parts[1]
-		} else {
+		default:
 			return "", "", fmt.Errorf("Unknown transfer protocol %s", uri.Scheme)
 		}
 	}
@@ -380,7 +381,7 @@ func newSmtpSender(ctx sendCtx) (io.WriteCloser, error) {
 func connectSmtp(starttls bool, host string) (*smtp.Client, error) {
 	serverName := host
 	if !strings.ContainsRune(host, ':') {
-		host = host + ":587" // Default to submission port
+		host += ":587" // Default to submission port
 	} else {
 		serverName = host[:strings.IndexRune(host, ':')]
 	}
@@ -402,14 +403,12 @@ func connectSmtp(starttls bool, host string) (*smtp.Client, error) {
 			conn.Close()
 			return nil, errors.Wrap(err, "StartTLS")
 		}
-	} else {
+	} else if starttls {
-		if starttls {
+		err := errors.New("STARTTLS requested, but not supported " +
-			err := errors.New("STARTTLS requested, but not supported " +
+			"by this SMTP server. Is someone tampering with your " +
-				"by this SMTP server. Is someone tampering with your " +
+			"connection?")
-				"connection?")
+		conn.Close()
-			conn.Close()
+		return nil, err
-			return nil, err
-		}
 	}
 	return conn, nil
 }
@@ -417,7 +416,7 @@ func connectSmtp(starttls bool, host string) (*smtp.Client, error) {
 func connectSmtps(host string) (*smtp.Client, error) {
 	serverName := host
 	if !strings.ContainsRune(host, ':') {
-		host = host + ":465" // Default to smtps port
+		host += ":465" // Default to smtps port
 	} else {
 		serverName = host[:strings.IndexRune(host, ':')]
 	}

commands/ct.go

@@ -40,15 +40,16 @@ func (ChangeTab) Execute(aerc *widgets.Aerc, args []string) error {
 	} else {
 		n, err := strconv.Atoi(joinedArgs)
 		if err == nil {
-			if strings.HasPrefix(joinedArgs, "+") {
+			switch {
+			case strings.HasPrefix(joinedArgs, "+"):
 				for ; n > 0; n-- {
 					aerc.NextTab()
 				}
-			} else if strings.HasPrefix(joinedArgs, "-") {
+			case strings.HasPrefix(joinedArgs, "-"):
 				for ; n < 0; n++ {
 					aerc.PrevTab()
 				}
-			} else {
+			default:
 				ok := aerc.SelectTabIndex(n)
 				if !ok {
 					return errors.New(

commands/msg/copy.go

@@ -36,8 +36,7 @@ func (Copy) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 	var createParents bool
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'p' {
-		case 'p':
 			createParents = true
 		}
 	}

commands/msg/mark.go

@@ -61,16 +61,17 @@ func (Mark) Execute(aerc *widgets.Aerc, args []string) error {
 		} else {
 			modFunc = store.Mark
 		}
-		if all {
+		switch {
+		case all:
 			uids := store.Uids()
 			for _, uid := range uids {
 				modFunc(uid)
 			}
 			return nil
-		} else if visual {
+		case visual:
 			store.ToggleVisualMark()
 			return nil
-		} else {
+		default:
 			modFunc(selected.Uid)
 			return nil
 		}
@@ -80,16 +81,17 @@ func (Mark) Execute(aerc *widgets.Aerc, args []string) error {
 			return fmt.Errorf("visual mode not supported for this command")
 		}
 
-		if all && toggle {
+		switch {
+		case all && toggle:
 			uids := store.Uids()
 			for _, uid := range uids {
 				store.ToggleMark(uid)
 			}
 			return nil
-		} else if all && !toggle {
+		case all && !toggle:
 			store.ClearVisualMark()
 			return nil
-		} else {
+		default:
 			store.Unmark(selected.Uid)
 			return nil
 		}

commands/msg/move.go

@@ -36,8 +36,7 @@ func (Move) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 	var createParents bool
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'p' {
-		case 'p':
 			createParents = true
 		}
 	}

commands/msg/read.go

@@ -102,11 +102,12 @@ func (FlagMsg) Execute(aerc *widgets.Aerc, args []string) error {
 			flagChosen = true
 		}
 	}
-	if toggle {
+	switch {
+	case toggle:
 		actionName = "Toggling"
-	} else if enable {
+	case enable:
 		actionName = "Setting"
-	} else {
+	default:
 		actionName = "Unsetting"
 	}
 	if optind != len(args) {

commands/msg/recall.go

@@ -42,8 +42,7 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 		return err
 	}
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'f' {
-		case 'f':
 			force = true
 		}
 	}

commands/new-account.go

@@ -28,8 +28,7 @@ func (NewAccount) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 	wizard := widgets.NewAccountWizard(aerc.Config(), aerc)
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 't' {
-		case 't':
 			wizard.ConfigureTemporaryAccount(true)
 		}
 	}

commands/quit.go

@@ -36,8 +36,7 @@ func (Quit) Execute(aerc *widgets.Aerc, args []string) error {
 		return err
 	}
 	for _, opt := range opts {
-		switch opt.Option {
+		if opt.Option == 'f' {
-		case 'f':
 			force = true
 		}
 	}

completer/completer.go

@@ -127,7 +127,7 @@ func (c *Completer) getAddressCmd(s string) (*exec.Cmd, error) {
 	if strings.TrimSpace(c.AddressBookCmd) == "" {
 		return nil, fmt.Errorf("no command configured")
 	}
-	queryCmd := strings.Replace(c.AddressBookCmd, "%s", s, -1)
+	queryCmd := strings.ReplaceAll(c.AddressBookCmd, "%s", s)
 	parts, err := shlex.Split(queryCmd)
 	if err != nil {
 		return nil, fmt.Errorf("could not lex command")

config/bindings.go

@@ -182,11 +182,12 @@ func ParseKeyStrokes(keystrokes string) ([]KeyStroke, error) {
 		switch tok {
 		case '<':
 			name, err := buf.ReadString(byte('>'))
-			if err == io.EOF {
+			switch {
+			case err == io.EOF:
 				return nil, errors.New("Expecting '>'")
-			} else if err != nil {
+			case err != nil:
 				return nil, err
-			} else if name == ">" {
+			case name == ">":
 				return nil, errors.New("Expected a key name")
 			}
 			name = name[:len(name)-1]

config/config.go

@@ -294,42 +294,45 @@ func loadAccountConfig(path string) ([]AccountConfig, error) {
 			return nil, err
 		}
 		for key, val := range sec.KeysHash() {
-			if key == "folders" {
+			switch key {
+			case "folders":
 				folders := strings.Split(val, ",")
 				sort.Strings(folders)
 				account.Folders = folders
-			} else if key == "folders-exclude" {
+			case "folders-exclude":
 				folders := strings.Split(val, ",")
 				sort.Strings(folders)
 				account.FoldersExclude = folders
-			} else if key == "source" {
+			case "source":
 				sourceRemoteConfig.Value = val
-			} else if key == "source-cred-cmd" {
+			case "source-cred-cmd":
 				sourceRemoteConfig.PasswordCmd = val
-			} else if key == "outgoing" {
+			case "outgoing":
 				account.Outgoing.Value = val
-			} else if key == "outgoing-cred-cmd" {
+			case "outgoing-cred-cmd":
 				account.Outgoing.PasswordCmd = val
-			} else if key == "from" {
+			case "from":
 				account.From = val
-			} else if key == "aliases" {
+			case "aliases":
 				account.Aliases = val
-			} else if key == "copy-to" {
+			case "copy-to":
 				account.CopyTo = val
-			} else if key == "archive" {
+			case "archive":
 				account.Archive = val
-			} else if key == "enable-folders-sort" {
+			case "enable-folders-sort":
 				account.EnableFoldersSort, _ = strconv.ParseBool(val)
-			} else if key == "pgp-key-id" {
+			case "pgp-key-id":
 				account.PgpKeyId = val
-			} else if key == "pgp-auto-sign" {
+			case "pgp-auto-sign":
 				account.PgpAutoSign, _ = strconv.ParseBool(val)
-			} else if key == "pgp-opportunistic-encrypt" {
+			case "pgp-opportunistic-encrypt":
 				account.PgpOpportunisticEncrypt, _ = strconv.ParseBool(val)
-			} else if key == "address-book-cmd" {
+			case "address-book-cmd":
 				account.AddressBookCmd = val
-			} else if key != "name" {
+			default:
-				account.Params[key] = val
+				if key != "name" {
+					account.Params[key] = val
+				}
 			}
 		}
 		if account.Source == "" {
@@ -428,25 +431,26 @@ func (config *AercConfig) LoadConfig(file *ini.File) error {
 				Command: cmd,
 				Filter:  match,
 			}
-			if strings.Contains(match, ",~") {
+			switch {
+			case strings.Contains(match, ",~"):
 				filter.FilterType = FILTER_HEADER
-				header := filter.Filter[:strings.Index(filter.Filter, ",")]
+				header := filter.Filter[:strings.Index(filter.Filter, ",")] //nolint:gocritic // guarded by strings.Contains
 				regex := filter.Filter[strings.Index(filter.Filter, "~")+1:]
 				filter.Header = strings.ToLower(header)
 				filter.Regex, err = regexp.Compile(regex)
 				if err != nil {
 					return err
 				}
-			} else if strings.ContainsRune(match, ',') {
+			case strings.ContainsRune(match, ','):
 				filter.FilterType = FILTER_HEADER
-				header := filter.Filter[:strings.Index(filter.Filter, ",")]
+				header := filter.Filter[:strings.Index(filter.Filter, ",")] //nolint:gocritic // guarded by strings.Contains
 				value := filter.Filter[strings.Index(filter.Filter, ",")+1:]
 				filter.Header = strings.ToLower(header)
 				filter.Regex, err = regexp.Compile(regexp.QuoteMeta(value))
 				if err != nil {
 					return err
 				}
-			} else {
+			default:
 				filter.FilterType = FILTER_MIMETYPE
 			}
 			config.Filters = append(config.Filters, filter)
@@ -475,8 +479,7 @@ func (config *AercConfig) LoadConfig(file *ini.File) error {
 			return err
 		}
 		for key, val := range compose.KeysHash() {
-			switch key {
+			if key == "header-layout" {
-			case "header-layout":
 				config.Compose.HeaderLayout = parseLayout(val)
 			}
 		}
@@ -531,21 +534,22 @@ func (config *AercConfig) LoadConfig(file *ini.File) error {
 		}
 
 		var index int
-		if strings.Contains(sectionName, "~") {
+		switch {
+		case strings.Contains(sectionName, "~"):
 			index = strings.Index(sectionName, "~")
 			regex := string(sectionName[index+1:])
 			contextualUi.Regex, err = regexp.Compile(regex)
 			if err != nil {
 				return err
 			}
-		} else if strings.Contains(sectionName, "=") {
+		case strings.Contains(sectionName, "="):
 			index = strings.Index(sectionName, "=")
 			value := string(sectionName[index+1:])
 			contextualUi.Regex, err = regexp.Compile(regexp.QuoteMeta(value))
 			if err != nil {
 				return err
 			}
-		} else {
+		default:
 			return fmt.Errorf("Invalid Ui Context regex in %s", sectionName)
 		}
 
@@ -650,8 +654,7 @@ func validatePgpProvider(section *ini.Section) error {
 		"internal": true,
 	}
 	for key, val := range section.KeysHash() {
-		switch key {
+		if key == "pgp-provider" {
-		case "pgp-provider":
 			if !m[strings.ToLower(val)] {
 				return fmt.Errorf("%v must be either 'gpg' or 'internal'", key)
 			}
@@ -857,10 +860,10 @@ func LoadConfigFromFile(root *string) (*AercConfig, error) {
 	// Base Bindings
 	for _, sectionName := range binds.SectionStrings() {
 		// Handle :: delimeter
-		baseSectionName := strings.Replace(sectionName, "::", "////", -1)
+		baseSectionName := strings.ReplaceAll(sectionName, "::", "////")
 		sections := strings.Split(baseSectionName, ":")
 		baseOnly := len(sections) == 1
-		baseSectionName = strings.Replace(sections[0], "////", "::", -1)
+		baseSectionName = strings.ReplaceAll(sections[0], "////", "::")
 
 		group, ok := baseGroups[strings.ToLower(baseSectionName)]
 		if !ok {

lib/auth/auth.go

@@ -82,14 +82,16 @@ func CreateParser(m Method) func(*mail.Header, []string) (*Details, error) {
 			}
 
 			identifier, results, err := authres.Parse(headerText)
-			if err != nil && err.Error() == "msgauth: unsupported version" {
+			// TODO: refactor to use errors.Is
+			switch {
+			case err != nil && err.Error() == "msgauth: unsupported version":
 				// Some MTA write their authres header without an identifier
 				// which does not conform to RFC but still exists in the wild
 				identifier, results, err = authres.Parse("unknown;" + headerText)
 				if err != nil {
 					return nil, err
 				}
-			} else if err != nil && err.Error() == "msgauth: malformed authentication method and value" {
+			case err != nil && err.Error() == "msgauth: malformed authentication method and value":
 				// the go-msgauth parser doesn't like semi-colons in the comments
 				// as a work-around we remove those
 				cleanHeader := cleaner.ReplaceAllString(headerText, "${1}${2}")
@@ -97,7 +99,7 @@ func CreateParser(m Method) func(*mail.Header, []string) (*Details, error) {
 				if err != nil {
 					return nil, err
 				}
-			} else if err != nil {
+			case err != nil:
 				return nil, err
 			}
 

lib/format/format.go

@@ -298,11 +298,12 @@ func ParseMessageFormat(format string, timeFmt string, thisDayTimeFmt string,
 			recent := false
 			answered := false
 			for _, flag := range ctx.MsgInfo.Flags {
-				if flag == models.SeenFlag {
+				switch flag {
+				case models.SeenFlag:
 					seen = true
-				} else if flag == models.RecentFlag {
+				case models.RecentFlag:
 					recent = true
-				} else if flag == models.AnsweredFlag {
+				case models.AnsweredFlag:
 					answered = true
 				}
 				if flag == models.DeletedFlag {

lib/msgstore.go

@@ -121,8 +121,7 @@ func (store *MessageStore) FetchHeaders(uids []uint32,
 	}
 	if len(toFetch) > 0 {
 		store.worker.PostAction(&types.FetchMessageHeaders{Uids: toFetch}, func(msg types.WorkerMessage) {
-			switch msg.(type) {
+			if _, ok := msg.(*types.Error); ok {
-			case *types.Error:
 				for _, uid := range toFetch {
 					delete(store.pendingHeaders, uid)
 					delete(store.headerCallbacks, uid)
@@ -153,8 +152,7 @@ func (store *MessageStore) FetchFull(uids []uint32, cb func(*types.FullMessage))
 		store.worker.PostAction(&types.FetchFullMessages{
 			Uids: toFetch,
 		}, func(msg types.WorkerMessage) {
-			switch msg.(type) {
+			if _, ok := msg.(*types.Error); ok {
-			case *types.Error:
 				for _, uid := range toFetch {
 					delete(store.pendingBodies, uid)
 					delete(store.bodyCallbacks, uid)
@@ -244,10 +242,8 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 	case *types.MessageInfo:
 		if existing, ok := store.Messages[msg.Info.Uid]; ok && existing != nil {
 			merge(existing, msg.Info)
-		} else {
+		} else if msg.Info.Envelope != nil {
-			if msg.Info.Envelope != nil {
+			store.Messages[msg.Info.Uid] = msg.Info
-				store.Messages[msg.Info.Uid] = msg.Info
-			}
 		}
 		seen := false
 		recent := false
@@ -441,8 +437,7 @@ func (store *MessageStore) Delete(uids []uint32,
 
 	store.worker.PostAction(&types.DeleteMessages{Uids: uids},
 		func(msg types.WorkerMessage) {
-			switch msg.(type) {
+			if _, ok := msg.(*types.Error); ok {
-			case *types.Error:
 				store.revertDeleted(uids)
 			}
 			cb(msg)
@@ -726,8 +721,7 @@ func (store *MessageStore) Search(args []string, cb func([]uint32)) {
 	store.worker.PostAction(&types.SearchDirectory{
 		Argv: args,
 	}, func(msg types.WorkerMessage) {
-		switch msg := msg.(type) {
+		if msg, ok := msg.(*types.SearchResults); ok {
-		case *types.SearchResults:
 			allowedUids := store.Uids()
 			uids := make([]uint32, 0, len(msg.Uids))
 			for _, uid := range msg.Uids {

lib/open.go

@@ -35,7 +35,7 @@ func NewXDGOpen(filename string) *xdgOpen {
 func (xdg *xdgOpen) SetArgs(args []string) {
 	args = append([]string{}, args...) // don't overwrite array of caller
 	filename := xdg.args[len(xdg.args)-1]
-	xdg.args = append(args, filename)
+	xdg.args = append(args, filename) //nolint:gocritic // intentional append to different slice
 }
 
 // Start the open handler.

lib/statusline/renderer.go

@@ -69,10 +69,8 @@ func contentInfo(acct *accountState, fldr *folderState, texter Texter) []string
 	var status []string
 	if fldr.FilterActivity != "" {
 		status = append(status, fldr.FilterActivity)
-	} else {
+	} else if fldr.Filter != "" {
-		if fldr.Filter != "" {
+		status = append(status, texter.FormatFilter(fldr.Filter))
-			status = append(status, texter.FormatFilter(fldr.Filter))
-		}
 	}
 	if fldr.Search != "" {
 		status = append(status, texter.FormatSearch(fldr.Search))

lib/structure_helpers.go

@@ -8,7 +8,7 @@ import (
 
 func FindPlaintext(bs *models.BodyStructure, path []int) []int {
 	for i, part := range bs.Parts {
-		cur := append(path, i+1)
+		cur := append(path, i+1) //nolint:gocritic // intentional append to different slice
 		if strings.ToLower(part.MIMEType) == "text" &&
 			strings.ToLower(part.MIMESubType) == "plain" {
 			return cur
@@ -24,7 +24,7 @@ func FindPlaintext(bs *models.BodyStructure, path []int) []int {
 
 func FindCalendartext(bs *models.BodyStructure, path []int) []int {
 	for i, part := range bs.Parts {
-		cur := append(path, i+1)
+		cur := append(path, i+1) //nolint:gocritic // intentional append to different slice
 		if strings.ToLower(part.MIMEType) == "text" &&
 			strings.ToLower(part.MIMESubType) == "calendar" {
 			return cur
@@ -40,7 +40,7 @@ func FindCalendartext(bs *models.BodyStructure, path []int) []int {
 
 func FindFirstNonMultipart(bs *models.BodyStructure, path []int) []int {
 	for i, part := range bs.Parts {
-		cur := append(path, i+1)
+		cur := append(path, i+1) //nolint:gocritic // intentional append to different slice
 		mimetype := strings.ToLower(part.MIMEType)
 		if mimetype != "multipart" {
 			return cur
@@ -55,7 +55,7 @@ func FindFirstNonMultipart(bs *models.BodyStructure, path []int) []int {
 
 func FindAllNonMultipart(bs *models.BodyStructure, path []int, pathlist [][]int) [][]int {
 	for i, part := range bs.Parts {
-		cur := append(path, i+1)
+		cur := append(path, i+1) //nolint:gocritic // intentional append to different slice
 		mimetype := strings.ToLower(part.MIMEType)
 		if mimetype != "multipart" {
 			tmp := make([]int, len(cur))

lib/ui/borders.go

@@ -76,8 +76,7 @@ func (bordered *Bordered) Draw(ctx *Context) {
 }
 
 func (bordered *Bordered) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch content := bordered.content.(type) {
+	if content, ok := bordered.content.(Mouseable); ok {
-	case Mouseable:
 		content.MouseEvent(localX, localY, event)
 	}
 }

lib/ui/grid.go

@@ -150,8 +150,7 @@ func (grid *Grid) Draw(ctx *Context) {
 }
 
 func (grid *Grid) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		invalid := grid.invalid
 
 		grid.mutex.RLock()

lib/ui/popover.go

@@ -16,13 +16,14 @@ func (p *Popover) Draw(ctx *Context) {
 		width = ctx.Width() - p.x
 	}
 
-	if p.y+p.height+1 < ctx.Height() {
+	switch {
+	case p.y+p.height+1 < ctx.Height():
 		// draw below
 		subcontext = ctx.Subcontext(p.x, p.y+1, width, p.height)
-	} else if p.y-p.height >= 0 {
+	case p.y-p.height >= 0:
 		// draw above
 		subcontext = ctx.Subcontext(p.x, p.y-p.height, width, p.height)
-	} else {
+	default:
 		// can't fit entirely above or below, so find the largest available
 		// vertical space and shrink to fit
 		if p.y > ctx.Height()-p.y {

lib/ui/stack.go

@@ -43,8 +43,7 @@ func (stack *Stack) Draw(ctx *Context) {
 
 func (stack *Stack) MouseEvent(localX int, localY int, event tcell.Event) {
 	if len(stack.children) > 0 {
-		switch element := stack.Peek().(type) {
+		if element, ok := stack.Peek().(Mouseable); ok {
-		case Mouseable:
 			element.MouseEvent(localX, localY, event)
 		}
 	}

lib/ui/tab.go

@@ -219,27 +219,28 @@ func (tabs *Tabs) moveTabPriv(to int, relative bool) {
 	}
 
 	tab := tabs.tabs[from]
-	if to > from {
+	switch {
+	case to > from:
 		copy(tabs.tabs[from:to], tabs.tabs[from+1:to+1])
 		for i, h := range tabs.history {
 			if h == from {
 				tabs.history[i] = to
 			}
 			if h > from && h <= to {
-				tabs.history[i] -= 1
+				tabs.history[i]--
 			}
 		}
-	} else if from > to {
+	case from > to:
 		copy(tabs.tabs[to+1:from+1], tabs.tabs[to:from])
 		for i, h := range tabs.history {
 			if h == from {
 				tabs.history[i] = to
 			}
 			if h >= to && h < from {
-				tabs.history[i] += 1
+				tabs.history[i]++
 			}
 		}
-	} else {
+	default:
 		return
 	}
 
@@ -339,7 +340,7 @@ func (tabs *Tabs) removeHistory(index int) {
 			continue
 		}
 		if item > index {
-			item = item - 1
+			item--
 		}
 		// dedup
 		if i > 0 && len(newHist) > 0 && item == newHist[len(newHist)-1] {
@@ -399,8 +400,7 @@ func (strip *TabStrip) MouseEvent(localX int, localY int, event tcell.Event) {
 	}
 	unfocus := func() { changeFocus(false) }
 	refocus := func() { changeFocus(true) }
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		switch event.Buttons() {
 		case tcell.Button1:
 			selectedTab, ok := strip.clicked(localX, localY)
@@ -484,8 +484,7 @@ func (content *TabContent) MouseEvent(localX int, localY int, event tcell.Event)
 	content.parent.m.Lock()
 	tab := content.tabs[content.curIndex]
 	content.parent.m.Unlock()
-	switch tabContent := tab.Content.(type) {
+	if tabContent, ok := tab.Content.(Mouseable); ok {
-	case Mouseable:
 		tabContent.MouseEvent(localX, localY, event)
 	}
 }

lib/ui/textinput.go

@@ -148,10 +148,8 @@ func (ti *TextInput) drawPopover(ctx *Context) {
 }
 
 func (ti *TextInput) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
+		if event.Buttons() == tcell.Button1 {
-		switch event.Buttons() {
-		case tcell.Button1:
 			if localX >= len(ti.prompt)+1 && localX <= len(ti.text[ti.scroll:])+len(ti.prompt)+1 {
 				ti.index = localX - len(ti.prompt) - 1
 				ti.ensureScroll()
@@ -190,7 +188,7 @@ func (ti *TextInput) ensureScroll() {
 func (ti *TextInput) insert(ch rune) {
 	left := ti.text[:ti.index]
 	right := ti.text[ti.index:]
-	ti.text = append(left, append([]rune{ch}, right...)...)
+	ti.text = append(left, append([]rune{ch}, right...)...) //nolint:gocritic // intentional append to different slice
 	ti.index++
 	ti.ensureScroll()
 	ti.Invalidate()
@@ -323,8 +321,7 @@ func (ti *TextInput) OnFocusLost(onFocusLost func(ti *TextInput)) {
 }
 
 func (ti *TextInput) Event(event tcell.Event) bool {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		switch event.Key() {
 		case tcell.KeyBackspace, tcell.KeyBackspace2:
 			ti.invalidateCompletions()
@@ -464,8 +461,7 @@ func (c *completions) prev() {
 }
 
 func (c *completions) Event(e tcell.Event) bool {
-	switch e := e.(type) {
+	if e, ok := e.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		switch e.Key() {
 		case tcell.KeyTab:
 			if len(c.options) == 1 && c.idx >= 0 {
@@ -496,7 +492,7 @@ func (c *completions) Event(e tcell.Event) bool {
 }
 
 func findStem(words []string) string {
-	if len(words) <= 0 {
+	if len(words) == 0 {
 		return ""
 	}
 	if len(words) == 1 {
@@ -519,7 +515,7 @@ func findStem(words []string) string {
 				return stem
 			}
 		}
-		stem = stem + string(r)
+		stem += string(r)
 		stemLen++
 	}
 }

lib/ui/ui.go

@@ -87,8 +87,7 @@ func (state *UI) Tick() bool {
 
 	select {
 	case event := <-state.tcEvents:
-		switch event := event.(type) {
+		if event, ok := event.(*tcell.EventResize); ok {
-		case *tcell.EventResize:
 			state.screen.Clear()
 			width, height := event.Size()
 			state.ctx = NewContext(width, height, state.screen, state.onPopover)

widgets/account-wizard.go

@@ -689,8 +689,7 @@ func (wizard *AccountWizard) Focus(focus bool) {
 
 func (wizard *AccountWizard) Event(event tcell.Event) bool {
 	interactive := wizard.getInteractive()
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		switch event.Key() {
 		case tcell.KeyUp:
 			fallthrough

widgets/account.go

@@ -362,11 +362,11 @@ func (acct *AccountView) onMessage(msg types.WorkerMessage) {
 						seen = true
 					}
 					if flag == models.RecentFlag {
-						recent = recent + 1
+						recent++
 					}
 				}
 				if !seen {
-					unseen = unseen + 1
+					unseen++
 				}
 			}
 			if accurate {
@@ -415,7 +415,7 @@ func (acct *AccountView) CheckMail() {
 		return
 	}
 	// Exclude selected mailbox, per IMAP specification
-	exclude := append(acct.AccountConfig().CheckMailExclude, acct.dirlist.Selected())
+	exclude := append(acct.AccountConfig().CheckMailExclude, acct.dirlist.Selected()) //nolint:gocritic // intentional append to different slice
 	dirs := acct.dirlist.List()
 	dirs = acct.dirlist.FilterDirs(dirs, acct.AccountConfig().CheckMailInclude, false)
 	dirs = acct.dirlist.FilterDirs(dirs, exclude, true)

widgets/aerc.go

@@ -456,10 +456,8 @@ func (aerc *Aerc) focus(item ui.Interactive) {
 		if ok {
 			interactive.Focus(false)
 		}
-	} else {
+	} else if ok {
-		if ok {
+		interactive.Focus(true)
-			interactive.Focus(true)
-		}
 	}
 }
 

widgets/authinfo.go

@@ -25,20 +25,17 @@ func (a *AuthInfo) Draw(ctx *ui.Context) {
 	defaultStyle := a.uiConfig.GetStyle(config.STYLE_DEFAULT)
 	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', defaultStyle)
 	var text string
-	if a.authdetails == nil {
+	switch {
+	case a.authdetails == nil:
 		text = "(no header)"
 		ctx.Printf(0, 0, defaultStyle, text)
-	} else if a.authdetails.Err != nil {
+	case a.authdetails.Err != nil:
 		style := a.uiConfig.GetStyle(config.STYLE_ERROR)
 		text = a.authdetails.Err.Error()
 		ctx.Printf(0, 0, style, text)
-	} else {
+	default:
 		checkBounds := func(x int) bool {
-			if x < ctx.Width() {
+			return x < ctx.Width()
-				return true
-			} else {
-				return false
-			}
 		}
 		setResult := func(result auth.Result) (string, tcell.Style) {
 			switch result {

widgets/compose.go

@@ -527,11 +527,12 @@ func (c *Composer) Close() {
 }
 
 func (c *Composer) Bindings() string {
-	if c.editor == nil {
+	switch c.editor {
+	case nil:
 		return "compose::review"
-	} else if c.editor == c.focusable[c.focused] {
+	case c.focusable[c.focused]:
 		return "compose::editor"
-	} else {
+	default:
 		return "compose"
 	}
 }
@@ -798,10 +799,8 @@ func (c *Composer) resetReview() {
 }
 
 func (c *Composer) termEvent(event tcell.Event) bool {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
+		if event.Buttons() == tcell.Button1 {
-		switch event.Buttons() {
-		case tcell.Button1:
 			c.FocusTerminal()
 			return true
 		}
@@ -1041,10 +1040,8 @@ func (he *headerEditor) Draw(ctx *ui.Context) {
 }
 
 func (he *headerEditor) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
+		if event.Buttons() == tcell.Button1 {
-		switch event.Buttons() {
-		case tcell.Button1:
 			he.focused = true
 		}
 
@@ -1120,7 +1117,7 @@ func newReviewMessage(composer *Composer, err error) *reviewMessage {
 			inputs = append(inputs, config.FormatKeyStrokes(input))
 		}
 		actions = append(actions, fmt.Sprintf("  %-6s  %-40s  %s",
-			strings.Join(inputs[:], ", "), name, cmd))
+			strings.Join(inputs, ", "), name, cmd))
 	}
 
 	spec := []ui.GridSpec{

widgets/dirlist.go

@@ -270,11 +270,12 @@ func (dirlist *DirectoryList) getRUEString(name string) string {
 	}
 	di := msgStore.DirInfo
 	rueString := ""
-	if di.Recent > 0 {
+	switch {
+	case di.Recent > 0:
 		rueString = fmt.Sprintf("%d/%d/%d", di.Recent, di.Unseen, di.Exists)
-	} else if di.Unseen > 0 {
+	case di.Unseen > 0:
 		rueString = fmt.Sprintf("%d/%d", di.Unseen, di.Exists)
-	} else if di.Exists > 0 {
+	case di.Exists > 0:
 		rueString = fmt.Sprintf("%d", di.Exists)
 	}
 	return rueString
@@ -358,8 +359,7 @@ func (dirlist *DirectoryList) drawScrollbar(ctx *ui.Context) {
 }
 
 func (dirlist *DirectoryList) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		switch event.Buttons() {
 		case tcell.Button1:
 			clickedDir, ok := dirlist.Clicked(localX, localY)

widgets/dirtree.go

@@ -129,8 +129,7 @@ func (dt *DirectoryTree) Draw(ctx *ui.Context) {
 }
 
 func (dt *DirectoryTree) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		switch event.Buttons() {
 		case tcell.Button1:
 			clickedDir, ok := dt.Clicked(localX, localY)
@@ -194,7 +193,7 @@ func (dt *DirectoryTree) NextPrev(delta int) {
 	}
 
 	for i := 0; i < delta; {
-		newIdx = newIdx + step
+		newIdx += step
 		if newIdx < 0 {
 			newIdx = ndirs - 1
 		} else if newIdx >= ndirs {
@@ -378,7 +377,7 @@ func buildTree(node *types.Thread, stree [][]string, defaultUid uint32) {
 	m := make(map[string][][]string)
 	for _, branch := range stree {
 		if len(branch) > 1 {
-			next := append(m[branch[0]], branch[1:])
+			next := append(m[branch[0]], branch[1:]) //nolint:gocritic // intentional append to different slice
 			m[branch[0]] = next
 		}
 	}

widgets/exline.go

@@ -72,8 +72,7 @@ func (ex *ExLine) Focus(focus bool) {
 }
 
 func (ex *ExLine) Event(event tcell.Event) bool {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		switch event.Key() {
 		case tcell.KeyEnter, tcell.KeyCtrlJ:
 			cmd := ex.input.String()

widgets/msglist.go

@@ -288,8 +288,7 @@ func (ml *MessageList) drawScrollbar(ctx *ui.Context) {
 }
 
 func (ml *MessageList) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		switch event.Buttons() {
 		case tcell.Button1:
 			if ml.aerc == nil {

widgets/msgviewer.go

@@ -182,7 +182,7 @@ func enumerateParts(acct *AccountView, conf *config.AercConfig,
 ) ([]*PartViewer, error) {
 	var parts []*PartViewer
 	for i, part := range body.Parts {
-		curindex := append(index, i+1)
+		curindex := append(index, i+1) //nolint:gocritic // intentional append to different slice
 		if part.MIMEType == "multipart" {
 			// Multipart meta-parts are faked
 			pv := &PartViewer{part: part}
@@ -437,8 +437,7 @@ func (ps *PartSwitcher) Draw(ctx *ui.Context) {
 }
 
 func (ps *PartSwitcher) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		switch event.Buttons() {
 		case tcell.Button1:
 			height := len(ps.parts)
@@ -785,7 +784,7 @@ func newNoFilterConfigured(pv *PartViewer) *ui.Grid {
 			inputs = append(inputs, config.FormatKeyStrokes(input))
 		}
 		actions = append(actions, fmt.Sprintf("  %-6s  %-29s  %s",
-			strings.Join(inputs[:], ", "), name, cmd))
+			strings.Join(inputs, ", "), name, cmd))
 	}
 
 	spec := []ui.GridSpec{

widgets/selector.go

@@ -132,8 +132,7 @@ func (sel *Selector) Focus(focus bool) {
 }
 
 func (sel *Selector) Event(event tcell.Event) bool {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		switch event.Key() {
 		case tcell.KeyCtrlH:
 			fallthrough

widgets/terminal.go

@@ -343,8 +343,7 @@ func (term *Terminal) Draw(ctx *ui.Context) {
 }
 
 func (term *Terminal) MouseEvent(localX int, localY int, event tcell.Event) {
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventMouse); ok {
-	case *tcell.EventMouse:
 		if term.OnEvent != nil {
 			if term.OnEvent(event) {
 				return
@@ -399,22 +398,20 @@ func (term *Terminal) Event(event tcell.Event) bool {
 	if term.closed {
 		return false
 	}
-	switch event := event.(type) {
+	if event, ok := event.(*tcell.EventKey); ok {
-	case *tcell.EventKey:
 		if event.Key() == tcell.KeyRune {
 			term.vterm.KeyboardUnichar(
 				event.Rune(), convertMods(event.Modifiers()))
-		} else {
+		} else if key, ok := keyMap[event.Key()]; ok {
-			if key, ok := keyMap[event.Key()]; ok {
+			switch {
-				if key.Key == vterm.KeyNone {
+			case key.Key == vterm.KeyNone:
-					term.vterm.KeyboardUnichar(
+				term.vterm.KeyboardUnichar(
-						key.Rune, key.Mod)
+					key.Rune, key.Mod)
-				} else if key.Mod == vterm.ModNone {
+			case key.Mod == vterm.ModNone:
-					term.vterm.KeyboardKey(key.Key,
+				term.vterm.KeyboardKey(key.Key,
-						convertMods(event.Modifiers()))
+					convertMods(event.Modifiers()))
-				} else {
+			default:
-					term.vterm.KeyboardKey(key.Key, key.Mod)
+				term.vterm.KeyboardKey(key.Key, key.Mod)
-				}
 			}
 		}
 		term.flushTerminal()
@@ -432,19 +429,21 @@ func (term *Terminal) styleFromCell(cell *vterm.ScreenCell) tcell.Style {
 		bg tcell.Color
 		fg tcell.Color
 	)
-	if background.IsDefaultBg() {
+	switch {
+	case background.IsDefaultBg():
 		bg = tcell.ColorDefault
-	} else if background.IsIndexed() {
+	case background.IsIndexed():
 		bg = tcell.Color(tcell.PaletteColor(int(background.GetIndex())))
-	} else if background.IsRgb() {
+	case background.IsRgb():
 		r, g, b := background.GetRGB()
 		bg = tcell.NewRGBColor(int32(r), int32(g), int32(b))
 	}
-	if foreground.IsDefaultFg() {
+	switch {
+	case foreground.IsDefaultFg():
 		fg = tcell.ColorDefault
-	} else if foreground.IsIndexed() {
+	case foreground.IsIndexed():
 		fg = tcell.Color(tcell.PaletteColor(int(foreground.GetIndex())))
-	} else if foreground.IsRgb() {
+	case foreground.IsRgb():
 		r, g, b := foreground.GetRGB()
 		fg = tcell.NewRGBColor(int32(r), int32(g), int32(b))
 	}

worker/imap/cache.go

@@ -165,9 +165,9 @@ func (w *IMAPWorker) cleanCache() {
 				logging.Errorf("cannot clean database %d: %v", w.selected.UidValidity, err)
 				continue
 			}
-			removed = removed + 1
+			removed++
 		}
-		scanned = scanned + 1
+		scanned++
 	}
 	iter.Release()
 	elapsed := time.Since(start)

worker/imap/idler.go

@@ -61,7 +61,8 @@ func (i *idler) isReady() bool {
 }
 
 func (i *idler) Start() {
-	if i.isReady() {
+	switch {
+	case i.isReady():
 		i.stop = make(chan struct{})
 
 		go func() {
@@ -87,16 +88,17 @@ func (i *idler) Start() {
 			}
 		}()
 
-	} else if i.isWaiting() {
+	case i.isWaiting():
 		i.log("not started: wait for idle to exit")
-	} else {
+	default:
 		i.log("not started: client not ready")
 	}
 }
 
 func (i *idler) Stop() error {
 	var reterr error
-	if i.isReady() {
+	switch {
+	case i.isReady():
 		close(i.stop)
 		select {
 		case err := <-i.done:
@@ -118,10 +120,10 @@ func (i *idler) Stop() error {
 
 			reterr = errIdleTimeout
 		}
-	} else if i.isWaiting() {
+	case i.isWaiting():
 		i.log("not stopped: still idleing/hanging")
 		reterr = errIdleModeHangs
-	} else {
+	default:
 		i.log("not stopped: client not ready")
 		reterr = nil
 	}

worker/imap/search.go

@@ -49,11 +49,12 @@ func parseSearch(args []string) (*imap.SearchCriteria, error) {
 			text = true
 		}
 	}
-	if text {
+	switch {
+	case text:
 		criteria.Text = args[optind:]
-	} else if body {
+	case body:
 		criteria.Body = args[optind:]
-	} else {
+	default:
 		for _, arg := range args[optind:] {
 			criteria.Header.Add("Subject", arg)
 		}

worker/lib/search.go

@@ -53,11 +53,12 @@ func GetSearchCriteria(args []string) (*searchCriteria, error) {
 			text = true
 		}
 	}
-	if text {
+	switch {
+	case text:
 		criteria.Text = args[optind:]
-	} else if body {
+	case body:
 		criteria.Body = args[optind:]
-	} else {
+	default:
 		for _, arg := range args[optind:] {
 			criteria.Header.Add("Subject", arg)
 		}

worker/lib/sort.go

@@ -74,13 +74,7 @@ func sortAddresses(messageInfos []*models.MessageInfo, criterion *types.SortCrit
 		if len(addressJ) > 0 {
 			firstJ = addressJ[0]
 		}
-		if firstI == nil && firstJ == nil {
+		if firstI != nil && firstJ != nil {
-			return false
-		} else if firstI == nil && firstJ != nil {
-			return false
-		} else if firstI != nil && firstJ == nil {
-			return true
-		} else /* firstI != nil && firstJ != nil */ {
 			getName := func(addr *mail.Address) string {
 				if addr.Name != "" {
 					return addr.Name
@@ -89,6 +83,8 @@ func sortAddresses(messageInfos []*models.MessageInfo, criterion *types.SortCrit
 				}
 			}
 			return getName(firstI) < getName(firstJ)
+		} else {
+			return firstI != nil && firstJ == nil
 		}
 	})
 }

worker/maildir/container.go

@@ -80,7 +80,7 @@ func (c *Container) ListFolders() ([]string, error) {
 				return filepath.SkipDir
 			}
 			dirPath = strings.TrimPrefix(dirPath, ".")
-			dirPath = strings.Replace(dirPath, ".", "/", -1)
+			dirPath = strings.ReplaceAll(dirPath, ".", "/")
 			folders = append(folders, dirPath)
 
 			// Since all mailboxes are stored in a single directory, don't
@@ -124,7 +124,7 @@ func (c *Container) Dir(name string) maildir.Dir {
 		if name == "INBOX" {
 			return maildir.Dir(c.dir)
 		}
-		return maildir.Dir(filepath.Join(c.dir, "."+strings.Replace(name, "/", ".", -1)))
+		return maildir.Dir(filepath.Join(c.dir, "."+strings.ReplaceAll(name, "/", ".")))
 	}
 	return maildir.Dir(filepath.Join(c.dir, name))
 }

worker/maildir/search.go

@@ -61,11 +61,12 @@ func parseSearch(args []string) (*searchCriteria, error) {
 			text = true
 		}
 	}
-	if text {
+	switch {
+	case text:
 		criteria.Text = args[optind:]
-	} else if body {
+	case body:
 		criteria.Body = args[optind:]
-	} else {
+	default:
 		for _, arg := range args[optind:] {
 			criteria.Header.Add("Subject", arg)
 		}

worker/maildir/worker.go

@@ -81,16 +81,18 @@ func (w *Worker) handleAction(action types.WorkerMessage) {
 		go w.handleCheckMail(msg)
 	default:
 		// Default handling, will be performed synchronously
-		if err := w.handleMessage(msg); err == errUnsupported {
+		err := w.handleMessage(msg)
+		switch {
+		case errors.Is(err, errUnsupported):
 			w.worker.PostMessage(&types.Unsupported{
 				Message: types.RespondTo(msg),
 			}, nil)
-		} else if err != nil {
+		case err != nil:
 			w.worker.PostMessage(&types.Error{
 				Message: types.RespondTo(msg),
 				Error:   err,
 			}, nil)
-		} else {
+		default:
 			w.done(msg)
 		}
 	}

worker/notmuch/lib/database.go

@@ -351,11 +351,12 @@ func (db *DB) makeThread(parent *types.Thread, msgs *notmuch.Messages,
 
 	// We want to return the root node
 	var root *types.Thread
-	if parent != nil {
+	switch {
+	case parent != nil:
 		root = parent
-	} else if lastSibling != nil {
+	case lastSibling != nil:
 		root = lastSibling // first iteration has no parent
-	} else {
+	default:
 		return nil // we don't have any messages at all
 	}