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>

13 files changed, 46 insertions, 59 deletions

diff --git a/lib/auth/auth.go b/lib/auth/auth.go
index 8a0a40fa..ea32ecd3 100644
--- a/lib/auth/auth.go
+++ b/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
 			}
 
diff --git a/lib/format/format.go b/lib/format/format.go
index 0d14cb19..42dd34a1 100644
--- a/lib/format/format.go
+++ b/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 {
diff --git a/lib/msgstore.go b/lib/msgstore.go
index dc000de7..efa6f732 100644
--- a/lib/msgstore.go
+++ b/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) {
-			case *types.Error:
+			if _, ok := msg.(*types.Error); ok {
 				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) {
-			case *types.Error:
+			if _, ok := msg.(*types.Error); ok {
 				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 {
-			if msg.Info.Envelope != nil {
-				store.Messages[msg.Info.Uid] = msg.Info
-			}
+		} else if msg.Info.Envelope != nil {
+			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) {
-			case *types.Error:
+			if _, ok := msg.(*types.Error); ok {
 				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) {
-		case *types.SearchResults:
+		if msg, ok := msg.(*types.SearchResults); ok {
 			allowedUids := store.Uids()
 			uids := make([]uint32, 0, len(msg.Uids))
 			for _, uid := range msg.Uids {
diff --git a/lib/open.go b/lib/open.go
index c5d4b1c0..c29ed009 100644
--- a/lib/open.go
+++ b/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.
diff --git a/lib/statusline/renderer.go b/lib/statusline/renderer.go
index 2ab05dd9..26c95c24 100644
--- a/lib/statusline/renderer.go
+++ b/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 {
-		if fldr.Filter != "" {
-			status = append(status, texter.FormatFilter(fldr.Filter))
-		}
+	} else if fldr.Filter != "" {
+		status = append(status, texter.FormatFilter(fldr.Filter))
 	}
 	if fldr.Search != "" {
 		status = append(status, texter.FormatSearch(fldr.Search))
diff --git a/lib/structure_helpers.go b/lib/structure_helpers.go
index 99a77a28..6f25e459 100644
--- a/lib/structure_helpers.go
+++ b/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))
diff --git a/lib/ui/borders.go b/lib/ui/borders.go
index 2c689886..92e29b06 100644
--- a/lib/ui/borders.go
+++ b/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) {
-	case Mouseable:
+	if content, ok := bordered.content.(Mouseable); ok {
 		content.MouseEvent(localX, localY, event)
 	}
 }
diff --git a/lib/ui/grid.go b/lib/ui/grid.go
index 2d195711..1eac2ee8 100644
--- a/lib/ui/grid.go
+++ b/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) {
-	case *tcell.EventMouse:
+	if event, ok := event.(*tcell.EventMouse); ok {
 		invalid := grid.invalid
 
 		grid.mutex.RLock()
diff --git a/lib/ui/popover.go b/lib/ui/popover.go
index 7a539de1..8c8c4cda 100644
--- a/lib/ui/popover.go
+++ b/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 {
diff --git a/lib/ui/stack.go b/lib/ui/stack.go
index d3722354..5ccf13bc 100644
--- a/lib/ui/stack.go
+++ b/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) {
-		case Mouseable:
+		if element, ok := stack.Peek().(Mouseable); ok {
 			element.MouseEvent(localX, localY, event)
 		}
 	}
diff --git a/lib/ui/tab.go b/lib/ui/tab.go
index 0c6b3f5b..df76ccca 100644
--- a/lib/ui/tab.go
+++ b/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) {
-	case *tcell.EventMouse:
+	if event, ok := event.(*tcell.EventMouse); ok {
 		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) {
-	case Mouseable:
+	if tabContent, ok := tab.Content.(Mouseable); ok {
 		tabContent.MouseEvent(localX, localY, event)
 	}
 }
diff --git a/lib/ui/textinput.go b/lib/ui/textinput.go
index 8f8f00d0..70dcb3f5 100644
--- a/lib/ui/textinput.go
+++ b/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) {
-	case *tcell.EventMouse:
-		switch event.Buttons() {
-		case tcell.Button1:
+	if event, ok := event.(*tcell.EventMouse); ok {
+		if event.Buttons() == 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) {
-	case *tcell.EventKey:
+	if event, ok := event.(*tcell.EventKey); ok {
 		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) {
-	case *tcell.EventKey:
+	if e, ok := e.(*tcell.EventKey); ok {
 		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++
 	}
 }
diff --git a/lib/ui/ui.go b/lib/ui/ui.go
index 1f618a6f..596000a5 100644
--- a/lib/ui/ui.go
+++ b/lib/ui/ui.go
@@ -87,8 +87,7 @@ func (state *UI) Tick() bool {
 
 	select {
 	case event := <-state.tcEvents:
-		switch event := event.(type) {
-		case *tcell.EventResize:
+		if event, ok := event.(*tcell.EventResize); ok {
 			state.screen.Clear()
 			width, height := event.Size()
 			state.ctx = NewContext(width, height, state.screen, state.onPopover)