style: Replace else if cascades with switch

Wiser coders than myself have come to the conclusion that a `switch` statement is almost always superior to a statement that includes any `else if`. The exceptions that I have found in our codebase are just these two: * The `if else` is followed by an additional statement before the next condition (separated by a `;`). * The whole thing is within a `for` loop and `break` statements are used. In this case, using `switch` would require tagging the `for` loop, which probably tips the balance. Why are `switch` statements more readable? For one, fewer curly braces. But more importantly, the conditions all have the same alignment, so the whole thing follows the natural flow of going down a list of conditions. With `else if`, in contrast, all conditions but the first are "hidden" behind `} else if `, harder to spot and (for no good reason) presented differently from the first condition. I'm sure the aforemention wise coders can list even more reasons. In any case, I like it so much that I have found myself recommending it in code reviews. I would like to make it a habit in our code base, without making it a hard requirement that we would test on the CI. But for that, there has to be a role model, so this commit eliminates all `if else` occurrences, unless it is autogenerated code or fits one of the exceptions above. Signed-off-by: beorn7 <beorn@grafana.com>
2024-09-19 23:37:31 -07:00 · 2023-04-12 16:14:31 +02:00 · 2023-04-12 16:14:31 +02:00 · 5b53aa1108
parent c3c7d44d84
commit 5b53aa1108
44 changed files with 340 additions and 253 deletions
--- a/cmd/prometheus/main_unix_test.go
+++ b/cmd/prometheus/main_unix_test.go
@ -72,9 +72,11 @@ Loop:
 	if !startedOk {
 		t.Fatal("prometheus didn't start in the specified timeout")
 	}
-	if err := prom.Process.Kill(); err == nil {
+	switch err := prom.Process.Kill(); {
+	case err == nil:
 		t.Errorf("prometheus didn't shutdown gracefully after sending the Interrupt signal")
-	} else if stoppedErr != nil && stoppedErr.Error() != "signal: interrupt" { // TODO - find a better way to detect when the process didn't exit as expected!
+	case stoppedErr != nil && stoppedErr.Error() != "signal: interrupt":
+		// TODO: find a better way to detect when the process didn't exit as expected!
 		t.Errorf("prometheus exited with an unexpected error: %v", stoppedErr)
 	}
 }
--- a/cmd/promtool/tsdb.go
+++ b/cmd/promtool/tsdb.go
@ -403,14 +403,15 @@ func openBlock(path, blockID string) (*tsdb.DBReadOnly, tsdb.BlockReader, error)
 		return nil, nil, err
 	}
 	var block tsdb.BlockReader
-	if blockID != "" {
+	switch {
+	case blockID != "":
 		for _, b := range blocks {
 			if b.Meta().ULID.String() == blockID {
 				block = b
 				break
 			}
 		}
-	} else if len(blocks) > 0 {
+	case len(blocks) > 0:
 		block = blocks[len(blocks)-1]
 	}
 	if block == nil {
--- a/discovery/dns/dns.go
+++ b/discovery/dns/dns.go
@ -285,21 +285,22 @@ func lookupWithSearchPath(name string, qtype uint16, logger log.Logger) (*dns.Ms
 	for _, lname := range conf.NameList(name) {
 		response, err := lookupFromAnyServer(lname, qtype, conf, logger)

-		if err != nil {
+		switch {
+		case err != nil:
 			// We can't go home yet, because a later name
 			// may give us a valid, successful answer.  However
 			// we can no longer say "this name definitely doesn't
 			// exist", because we did not get that answer for
 			// at least one name.
 			allResponsesValid = false
-		} else if response.Rcode == dns.RcodeSuccess {
+		case response.Rcode == dns.RcodeSuccess:
 			// Outcome 1: GOLD!
 			return response, nil
 		}
 	}

 	if allResponsesValid {
-		// Outcome 2: everyone says NXDOMAIN, that's good enough for me
+		// Outcome 2: everyone says NXDOMAIN, that's good enough for me.
 		return &dns.Msg{}, nil
 	}
 	// Outcome 3: boned.
--- a/discovery/kubernetes/kubernetes.go
+++ b/discovery/kubernetes/kubernetes.go
@ -299,12 +299,13 @@ func New(l log.Logger, conf *SDConfig) (*Discovery, error) {
 		err          error
 		ownNamespace string
 	)
-	if conf.KubeConfig != "" {
+	switch {
+	case conf.KubeConfig != "":
 		kcfg, err = clientcmd.BuildConfigFromFlags("", conf.KubeConfig)
 		if err != nil {
 			return nil, err
 		}
-	} else if conf.APIServer.URL == nil {
+	case conf.APIServer.URL == nil:
 		// Use the Kubernetes provided pod service account
 		// as described in https://kubernetes.io/docs/admin/service-accounts-admin/
 		kcfg, err = rest.InClusterConfig()
@ -324,7 +325,7 @@ func New(l log.Logger, conf *SDConfig) (*Discovery, error) {
 		}

 		level.Info(l).Log("msg", "Using pod service account via in-cluster config")
-	} else {
+	default:
 		rt, err := config.NewRoundTripperFromConfig(conf.HTTPClientConfig, "kubernetes_sd")
 		if err != nil {
 			return nil, err
--- a/discovery/linode/linode.go
+++ b/discovery/linode/linode.go
@ -250,19 +250,20 @@ func (d *Discovery) refreshData(ctx context.Context) ([]*targetgroup.Group, erro
 					continue
 				}

-				if detailedIP.Public && publicIPv4 == "" {
+				switch {
+				case detailedIP.Public && publicIPv4 == "":
 					publicIPv4 = detailedIP.Address

 					if detailedIP.RDNS != "" && detailedIP.RDNS != "null" {
 						publicIPv4RDNS = detailedIP.RDNS
 					}
-				} else if !detailedIP.Public && privateIPv4 == "" {
+				case !detailedIP.Public && privateIPv4 == "":
 					privateIPv4 = detailedIP.Address

 					if detailedIP.RDNS != "" && detailedIP.RDNS != "null" {
 						privateIPv4RDNS = detailedIP.RDNS
 					}
-				} else {
+				default:
 					extraIPs = append(extraIPs, detailedIP.Address)
 				}
 			}
--- a/discovery/marathon/marathon.go
+++ b/discovery/marathon/marathon.go
@ -136,9 +136,10 @@ func NewDiscovery(conf SDConfig, logger log.Logger) (*Discovery, error) {
 		return nil, err
 	}

-	if len(conf.AuthToken) > 0 {
+	switch {
+	case len(conf.AuthToken) > 0:
 		rt, err = newAuthTokenRoundTripper(conf.AuthToken, rt)
-	} else if len(conf.AuthTokenFile) > 0 {
+	case len(conf.AuthTokenFile) > 0:
 		rt, err = newAuthTokenFileRoundTripper(conf.AuthTokenFile, rt)
 	}
 	if err != nil {
@ -400,19 +401,20 @@ func targetsForApp(app *app) []model.LabelSet {
 	var labels []map[string]string
 	var prefix string

-	if len(app.Container.PortMappings) != 0 {
+	switch {
+	case len(app.Container.PortMappings) != 0:
 		// In Marathon 1.5.x the "container.docker.portMappings" object was moved
 		// to "container.portMappings".
 		ports, labels = extractPortMapping(app.Container.PortMappings, app.isContainerNet())
 		prefix = portMappingLabelPrefix

-	} else if len(app.Container.Docker.PortMappings) != 0 {
+	case len(app.Container.Docker.PortMappings) != 0:
 		// Prior to Marathon 1.5 the port mappings could be found at the path
 		// "container.docker.portMappings".
 		ports, labels = extractPortMapping(app.Container.Docker.PortMappings, app.isContainerNet())
 		prefix = portMappingLabelPrefix

-	} else if len(app.PortDefinitions) != 0 {
+	case len(app.PortDefinitions) != 0:
 		// PortDefinitions deprecates the "ports" array and can be used to specify
 		// a list of ports with metadata in case a mapping is not required.
 		ports = make([]uint32, len(app.PortDefinitions))
--- a/documentation/examples/remote_storage/remote_storage_adapter/influxdb/client.go
+++ b/documentation/examples/remote_storage/remote_storage_adapter/influxdb/client.go
@ -290,13 +290,14 @@ func mergeSamples(a, b []prompb.Sample) []prompb.Sample {
 	result := make([]prompb.Sample, 0, len(a)+len(b))
 	i, j := 0, 0
 	for i < len(a) && j < len(b) {
-		if a[i].Timestamp < b[j].Timestamp {
+		switch {
+		case a[i].Timestamp < b[j].Timestamp:
 			result = append(result, a[i])
 			i++
-		} else if a[i].Timestamp > b[j].Timestamp {
+		case a[i].Timestamp > b[j].Timestamp:
 			result = append(result, b[j])
 			j++
-		} else {
+		default:
 			result = append(result, a[i])
 			i++
 			j++
--- a/model/histogram/float_histogram.go
+++ b/model/histogram/float_histogram.go
@ -824,10 +824,11 @@ mergeLoop: // Merge together all buckets from the original schema that fall into
 			origIdx += span.Offset
 		}
 		currIdx := i.targetIdx(origIdx)
-		if firstPass {
+		switch {
+		case firstPass:
 			i.currIdx = currIdx
 			firstPass = false
-		} else if currIdx != i.currIdx {
+		case currIdx != i.currIdx:
 			// Reached next bucket in targetSchema.
 			// Do not actually forward to the next bucket, but break out.
 			break mergeLoop
--- a/model/labels/labels.go
+++ b/model/labels/labels.go
@ -169,11 +169,12 @@ func (ls Labels) HashForLabels(b []byte, names ...string) (uint64, []byte) {
 	b = b[:0]
 	i, j := 0, 0
 	for i < len(ls) && j < len(names) {
-		if names[j] < ls[i].Name {
+		switch {
+		case names[j] < ls[i].Name:
 			j++
-		} else if ls[i].Name < names[j] {
+		case ls[i].Name < names[j]:
 			i++
-		} else {
+		default:
 			b = append(b, ls[i].Name...)
 			b = append(b, seps[0])
 			b = append(b, ls[i].Value...)
@ -213,11 +214,12 @@ func (ls Labels) BytesWithLabels(buf []byte, names ...string) []byte {
 	b.WriteByte(labelSep)
 	i, j := 0, 0
 	for i < len(ls) && j < len(names) {
-		if names[j] < ls[i].Name {
+		switch {
+		case names[j] < ls[i].Name:
 			j++
-		} else if ls[i].Name < names[j] {
+		case ls[i].Name < names[j]:
 			i++
-		} else {
+		default:
 			if b.Len() > 1 {
 				b.WriteByte(seps[0])
 			}
--- a/promql/engine.go
+++ b/promql/engine.go
@ -400,7 +400,7 @@ func (ng *Engine) SetQueryLogger(l QueryLogger) {
 }

 // NewInstantQuery returns an evaluation query for the given expression at the given time.
-func (ng *Engine) NewInstantQuery(ctx context.Context, q storage.Queryable, opts *QueryOpts, qs string, ts time.Time) (Query, error) {
+func (ng *Engine) NewInstantQuery(_ context.Context, q storage.Queryable, opts *QueryOpts, qs string, ts time.Time) (Query, error) {
 	expr, err := parser.ParseExpr(qs)
 	if err != nil {
 		return nil, err
@ -416,7 +416,7 @@ func (ng *Engine) NewInstantQuery(ctx context.Context, q storage.Queryable, opts

 // NewRangeQuery returns an evaluation query for the given time range and with
 // the resolution set by the interval.
-func (ng *Engine) NewRangeQuery(ctx context.Context, q storage.Queryable, opts *QueryOpts, qs string, start, end time.Time, interval time.Duration) (Query, error) {
+func (ng *Engine) NewRangeQuery(_ context.Context, q storage.Queryable, opts *QueryOpts, qs string, start, end time.Time, interval time.Duration) (Query, error) {
 	expr, err := parser.ParseExpr(qs)
 	if err != nil {
 		return nil, err
@ -1979,7 +1979,7 @@ func (ev *evaluator) matrixIterSlice(
 		//   (b) the number of samples is relatively small.
 		// so a linear search will be as fast as a binary search.
 		var drop int
-		for drop = 0; histograms[drop].T < mint; drop++ {
+		for drop = 0; histograms[drop].T < mint; drop++ { // nolint:revive
 		}
 		ev.currentSamples -= drop
 		copy(histograms, histograms[drop:])
@ -2096,13 +2096,13 @@ func (ev *evaluator) VectorAnd(lhs, rhs Vector, matching *parser.VectorMatching,
 }

 func (ev *evaluator) VectorOr(lhs, rhs Vector, matching *parser.VectorMatching, lhsh, rhsh []EvalSeriesHelper, enh *EvalNodeHelper) Vector {
-	if matching.Card != parser.CardManyToMany {
+	switch {
+	case matching.Card != parser.CardManyToMany:
 		panic("set operations must only use many-to-many matching")
-	}
-	if len(lhs) == 0 { // Short-circuit.
+	case len(lhs) == 0: // Short-circuit.
 		enh.Out = append(enh.Out, rhs...)
 		return enh.Out
-	} else if len(rhs) == 0 {
+	case len(rhs) == 0:
 		enh.Out = append(enh.Out, lhs...)
 		return enh.Out
 	}
@ -2221,13 +2221,14 @@ func (ev *evaluator) VectorBinop(op parser.ItemType, lhs, rhs Vector, matching *
 			hl, hr = hr, hl
 		}
 		floatValue, histogramValue, keep := vectorElemBinop(op, fl, fr, hl, hr)
-		if returnBool {
+		switch {
+		case returnBool:
 			if keep {
 				floatValue = 1.0
 			} else {
 				floatValue = 0.0
 			}
-		} else if !keep {
+		case !keep:
 			continue
 		}
 		metric := resultMetric(ls.Metric, rs.Metric, op, matching, enh)
@ -2514,14 +2515,15 @@ func (ev *evaluator) aggregation(op parser.ItemType, grouping []string, without
 		if !ok {
 			var m labels.Labels
 			enh.resetBuilder(metric)
-			if without {
+			switch {
+			case without:
 				enh.lb.Del(grouping...)
 				enh.lb.Del(labels.MetricName)
 				m = enh.lb.Labels()
-			} else if len(grouping) > 0 {
+			case len(grouping) > 0:
 				enh.lb.Keep(grouping...)
 				m = enh.lb.Labels()
-			} else {
+			default:
 				m = labels.EmptyLabels()
 			}
 			newAgg := &groupedAggregation{
@ -2530,9 +2532,10 @@ func (ev *evaluator) aggregation(op parser.ItemType, grouping []string, without
 				mean:       s.F,
 				groupCount: 1,
 			}
-			if s.H == nil {
+			switch {
+			case s.H == nil:
 				newAgg.hasFloat = true
-			} else if op == parser.SUM {
+			case op == parser.SUM:
 				newAgg.histogramValue = s.H.Copy()
 				newAgg.hasHistogram = true
 			}
@ -2542,9 +2545,10 @@ func (ev *evaluator) aggregation(op parser.ItemType, grouping []string, without

 			inputVecLen := int64(len(vec))
 			resultSize := k
-			if k > inputVecLen {
+			switch {
+			case k > inputVecLen:
 				resultSize = inputVecLen
-			} else if k == 0 {
+			case k == 0:
 				resultSize = 1
 			}
 			switch op {
@ -2637,12 +2641,13 @@ func (ev *evaluator) aggregation(op parser.ItemType, grouping []string, without

 		case parser.TOPK:
 			// We build a heap of up to k elements, with the smallest element at heap[0].
-			if int64(len(group.heap)) < k {
+			switch {
+			case int64(len(group.heap)) < k:
 				heap.Push(&group.heap, &Sample{
 					F:      s.F,
 					Metric: s.Metric,
 				})
-			} else if group.heap[0].F < s.F || (math.IsNaN(group.heap[0].F) && !math.IsNaN(s.F)) {
+			case group.heap[0].F < s.F || (math.IsNaN(group.heap[0].F) && !math.IsNaN(s.F)):
 				// This new element is bigger than the previous smallest element - overwrite that.
 				group.heap[0] = Sample{
 					F:      s.F,
@ -2655,12 +2660,13 @@ func (ev *evaluator) aggregation(op parser.ItemType, grouping []string, without

 		case parser.BOTTOMK:
 			// We build a heap of up to k elements, with the biggest element at heap[0].
-			if int64(len(group.reverseHeap)) < k {
+			switch {
+			case int64(len(group.reverseHeap)) < k:
 				heap.Push(&group.reverseHeap, &Sample{
 					F:      s.F,
 					Metric: s.Metric,
 				})
-			} else if group.reverseHeap[0].F > s.F || (math.IsNaN(group.reverseHeap[0].F) && !math.IsNaN(s.F)) {
+			case group.reverseHeap[0].F > s.F || (math.IsNaN(group.reverseHeap[0].F) && !math.IsNaN(s.F)):
 				// This new element is smaller than the previous biggest element - overwrite that.
 				group.reverseHeap[0] = Sample{
 					F:      s.F,
@ -2819,9 +2825,10 @@ func PreprocessExpr(expr parser.Expr, start, end time.Time) parser.Expr {
 func preprocessExprHelper(expr parser.Expr, start, end time.Time) bool {
 	switch n := expr.(type) {
 	case *parser.VectorSelector:
-		if n.StartOrEnd == parser.START {
+		switch n.StartOrEnd {
+		case parser.START:
 			n.Timestamp = makeInt64Pointer(timestamp.FromTime(start))
-		} else if n.StartOrEnd == parser.END {
+		case parser.END:
 			n.Timestamp = makeInt64Pointer(timestamp.FromTime(end))
 		}
 		return n.Timestamp != nil
@ -2878,9 +2885,10 @@ func preprocessExprHelper(expr parser.Expr, start, end time.Time) bool {
 		if isInvariant {
 			n.Expr = newStepInvariantExpr(n.Expr)
 		}
-		if n.StartOrEnd == parser.START {
+		switch n.StartOrEnd {
+		case parser.START:
 			n.Timestamp = makeInt64Pointer(timestamp.FromTime(start))
-		} else if n.StartOrEnd == parser.END {
+		case parser.END:
 			n.Timestamp = makeInt64Pointer(timestamp.FromTime(end))
 		}
 		return n.Timestamp != nil
--- a/promql/functions.go
+++ b/promql/functions.go
@ -804,12 +804,14 @@ func funcPi(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) V
 // === sgn(Vector parser.ValueTypeVector) Vector ===
 func funcSgn(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) Vector {
 	return simpleFunc(vals, enh, func(v float64) float64 {
-		if v < 0 {
+		switch {
+		case v < 0:
 			return -1
-		} else if v > 0 {
+		case v > 0:
 			return 1
+		default:
+			return v
 		}
-		return v
 	})
 }

--- a/promql/parser/ast.go
+++ b/promql/parser/ast.go
@ -368,13 +368,14 @@ func Children(node Node) []Node {
 	case *AggregateExpr:
 		// While this does not look nice, it should avoid unnecessary allocations
 		// caused by slice resizing
-		if n.Expr == nil && n.Param == nil {
+		switch {
+		case n.Expr == nil && n.Param == nil:
 			return nil
-		} else if n.Expr == nil {
+		case n.Expr == nil:
 			return []Node{n.Param}
-		} else if n.Param == nil {
+		case n.Param == nil:
 			return []Node{n.Expr}
-		} else {
+		default:
 			return []Node{n.Expr, n.Param}
 		}
 	case *BinaryExpr:
--- a/promql/parser/lex.go
+++ b/promql/parser/lex.go
@ -347,9 +347,10 @@ func lexStatements(l *Lexer) stateFn {

 	switch r := l.next(); {
 	case r == eof:
-		if l.parenDepth != 0 {
+		switch {
+		case l.parenDepth != 0:
 			return l.errorf("unclosed left parenthesis")
-		} else if l.bracketOpen {
+		case l.bracketOpen:
 			return l.errorf("unclosed left bracket")
 		}
 		l.emit(EOF)
@ -371,12 +372,13 @@ func lexStatements(l *Lexer) stateFn {
 	case r == '^':
 		l.emit(POW)
 	case r == '=':
-		if t := l.peek(); t == '=' {
+		switch t := l.peek(); t {
+		case '=':
 			l.next()
 			l.emit(EQLC)
-		} else if t == '~' {
+		case '~':
 			return l.errorf("unexpected character after '=': %q", t)
-		} else {
+		default:
 			l.emit(EQL)
 		}
 	case r == '!':
@ -791,11 +793,12 @@ Loop:
 		default:
 			l.backup()
 			word := l.input[l.start:l.pos]
-			if kw, ok := key[strings.ToLower(word)]; ok {
+			switch kw, ok := key[strings.ToLower(word)]; {
+			case ok:
 				l.emit(kw)
-			} else if !strings.Contains(word, ":") {
+			case !strings.Contains(word, ":"):
 				l.emit(IDENTIFIER)
-			} else {
+			default:
 				l.emit(METRIC_IDENTIFIER)
 			}
 			break Loop
--- a/promql/parser/parse.go
+++ b/promql/parser/parse.go
@ -270,14 +270,15 @@ var errUnexpected = errors.New("unexpected error")
 // recover is the handler that turns panics into returns from the top level of Parse.
 func (p *parser) recover(errp *error) {
 	e := recover()
-	if _, ok := e.(runtime.Error); ok {
+	switch _, ok := e.(runtime.Error); {
+	case ok:
 		// Print the stack trace but do not inhibit the running application.
 		buf := make([]byte, 64<<10)
 		buf = buf[:runtime.Stack(buf, false)]

 		fmt.Fprintf(os.Stderr, "parser panic: %v\n%s", e, buf)
 		*errp = errUnexpected
-	} else if e != nil {
+	case e != nil:
 		*errp = e.(error)
 	}
 }
@ -518,20 +519,18 @@ func (p *parser) checkAST(node Node) (typ ValueType) {
 			p.addParseErrf(n.RHS.PositionRange(), "binary expression must contain only scalar and instant vector types")
 		}

-		if (lt != ValueTypeVector || rt != ValueTypeVector) && n.VectorMatching != nil {
+		switch {
+		case (lt != ValueTypeVector || rt != ValueTypeVector) && n.VectorMatching != nil:
 			if len(n.VectorMatching.MatchingLabels) > 0 {
 				p.addParseErrf(n.PositionRange(), "vector matching only allowed between instant vectors")
 			}
 			n.VectorMatching = nil
-		} else {
-			// Both operands are Vectors.
-			if n.Op.IsSetOperator() {
-				if n.VectorMatching.Card == CardOneToMany || n.VectorMatching.Card == CardManyToOne {
-					p.addParseErrf(n.PositionRange(), "no grouping allowed for %q operation", n.Op)
-				}
-				if n.VectorMatching.Card != CardManyToMany {
-					p.addParseErrf(n.PositionRange(), "set operations must always be many-to-many")
-				}
+		case n.Op.IsSetOperator(): // Both operands are Vectors.
+			if n.VectorMatching.Card == CardOneToMany || n.VectorMatching.Card == CardManyToOne {
+				p.addParseErrf(n.PositionRange(), "no grouping allowed for %q operation", n.Op)
+			}
+			if n.VectorMatching.Card != CardManyToMany {
+				p.addParseErrf(n.PositionRange(), "set operations must always be many-to-many")
 			}
 		}

@ -708,9 +707,10 @@ func (p *parser) addOffset(e Node, offset time.Duration) {
 	}

 	// it is already ensured by parseDuration func that there never will be a zero offset modifier
-	if *orgoffsetp != 0 {
+	switch {
+	case *orgoffsetp != 0:
 		p.addParseErrf(e.PositionRange(), "offset may not be set multiple times")
-	} else if orgoffsetp != nil {
+	case orgoffsetp != nil:
 		*orgoffsetp = offset
 	}

--- a/promql/parser/printer.go
+++ b/promql/parser/printer.go
@ -124,17 +124,19 @@ func (node *MatrixSelector) String() string {
 	// Copy the Vector selector before changing the offset
 	vecSelector := *node.VectorSelector.(*VectorSelector)
 	offset := ""
-	if vecSelector.OriginalOffset > time.Duration(0) {
+	switch {
+	case vecSelector.OriginalOffset > time.Duration(0):
 		offset = fmt.Sprintf(" offset %s", model.Duration(vecSelector.OriginalOffset))
-	} else if vecSelector.OriginalOffset < time.Duration(0) {
+	case vecSelector.OriginalOffset < time.Duration(0):
 		offset = fmt.Sprintf(" offset -%s", model.Duration(-vecSelector.OriginalOffset))
 	}
 	at := ""
-	if vecSelector.Timestamp != nil {
+	switch {
+	case vecSelector.Timestamp != nil:
 		at = fmt.Sprintf(" @ %.3f", float64(*vecSelector.Timestamp)/1000.0)
-	} else if vecSelector.StartOrEnd == START {
+	case vecSelector.StartOrEnd == START:
 		at = " @ start()"
-	} else if vecSelector.StartOrEnd == END {
+	case vecSelector.StartOrEnd == END:
 		at = " @ end()"
 	}

@ -162,17 +164,19 @@ func (node *SubqueryExpr) getSubqueryTimeSuffix() string {
 		step = model.Duration(node.Step).String()
 	}
 	offset := ""
-	if node.OriginalOffset > time.Duration(0) {
+	switch {
+	case node.OriginalOffset > time.Duration(0):
 		offset = fmt.Sprintf(" offset %s", model.Duration(node.OriginalOffset))
-	} else if node.OriginalOffset < time.Duration(0) {
+	case node.OriginalOffset < time.Duration(0):
 		offset = fmt.Sprintf(" offset -%s", model.Duration(-node.OriginalOffset))
 	}
 	at := ""
-	if node.Timestamp != nil {
+	switch {
+	case node.Timestamp != nil:
 		at = fmt.Sprintf(" @ %.3f", float64(*node.Timestamp)/1000.0)
-	} else if node.StartOrEnd == START {
+	case node.StartOrEnd == START:
 		at = " @ start()"
-	} else if node.StartOrEnd == END {
+	case node.StartOrEnd == END:
 		at = " @ end()"
 	}
 	return fmt.Sprintf("[%s:%s]%s%s", model.Duration(node.Range), step, at, offset)
@ -207,17 +211,19 @@ func (node *VectorSelector) String() string {
 		labelStrings = append(labelStrings, matcher.String())
 	}
 	offset := ""
-	if node.OriginalOffset > time.Duration(0) {
+	switch {
+	case node.OriginalOffset > time.Duration(0):
 		offset = fmt.Sprintf(" offset %s", model.Duration(node.OriginalOffset))
-	} else if node.OriginalOffset < time.Duration(0) {
+	case node.OriginalOffset < time.Duration(0):
 		offset = fmt.Sprintf(" offset -%s", model.Duration(-node.OriginalOffset))
 	}
 	at := ""
-	if node.Timestamp != nil {
+	switch {
+	case node.Timestamp != nil:
 		at = fmt.Sprintf(" @ %.3f", float64(*node.Timestamp)/1000.0)
-	} else if node.StartOrEnd == START {
+	case node.StartOrEnd == START:
 		at = " @ start()"
-	} else if node.StartOrEnd == END {
+	case node.StartOrEnd == END:
 		at = " @ end()"
 	}

--- a/promql/quantile.go
+++ b/promql/quantile.go
@ -169,11 +169,12 @@ func histogramQuantile(q float64, h *histogram.FloatHistogram) float64 {
 		}
 	}
 	if bucket.Lower < 0 && bucket.Upper > 0 {
-		if len(h.NegativeBuckets) == 0 && len(h.PositiveBuckets) > 0 {
+		switch {
+		case len(h.NegativeBuckets) == 0 && len(h.PositiveBuckets) > 0:
 			// The result is in the zero bucket and the histogram has only
 			// positive buckets. So we consider 0 to be the lower bound.
 			bucket.Lower = 0
-		} else if len(h.PositiveBuckets) == 0 && len(h.NegativeBuckets) > 0 {
+		case len(h.PositiveBuckets) == 0 && len(h.NegativeBuckets) > 0:
 			// The result is in the zero bucket and the histogram has only
 			// negative buckets. So we consider 0 to be the upper bound.
 			bucket.Upper = 0
@ -244,12 +245,13 @@ func histogramFraction(lower, upper float64, h *histogram.FloatHistogram) float6
 	for it.Next() {
 		b := it.At()
 		if b.Lower < 0 && b.Upper > 0 {
-			if len(h.NegativeBuckets) == 0 && len(h.PositiveBuckets) > 0 {
+			switch {
+			case len(h.NegativeBuckets) == 0 && len(h.PositiveBuckets) > 0:
 				// This is the zero bucket and the histogram has only
 				// positive buckets. So we consider 0 to be the lower
 				// bound.
 				b.Lower = 0
-			} else if len(h.PositiveBuckets) == 0 && len(h.NegativeBuckets) > 0 {
+			case len(h.PositiveBuckets) == 0 && len(h.NegativeBuckets) > 0:
 				// This is in the zero bucket and the histogram has only
 				// negative buckets. So we consider 0 to be the upper
 				// bound.
--- a/rules/alerting_test.go
+++ b/rules/alerting_test.go
@ -587,10 +587,10 @@ func TestAlertingRuleLimit(t *testing.T) {
 	evalTime := time.Unix(0, 0)

 	for _, test := range tests {
-		_, err := rule.Eval(suite.Context(), evalTime, EngineQueryFunc(suite.QueryEngine(), suite.Storage()), nil, test.limit)
-		if err != nil {
+		switch _, err := rule.Eval(suite.Context(), evalTime, EngineQueryFunc(suite.QueryEngine(), suite.Storage()), nil, test.limit); {
+		case err != nil:
 			require.EqualError(t, err, test.err)
-		} else if test.err != "" {
+		case test.err != "":
 			t.Errorf("Expected errror %s, got none", test.err)
 		}
 	}
--- a/rules/manager_test.go
+++ b/rules/manager_test.go
@ -481,17 +481,18 @@ func TestForStateRestore(t *testing.T) {
 		})

 		// Checking if we have restored it correctly.
-		if tst.noRestore {
+		switch {
+		case tst.noRestore:
 			require.Equal(t, tst.num, len(got))
 			for _, e := range got {
 				require.Equal(t, e.ActiveAt, restoreTime)
 			}
-		} else if tst.gracePeriod {
+		case tst.gracePeriod:
 			require.Equal(t, tst.num, len(got))
 			for _, e := range got {
 				require.Equal(t, opts.ForGracePeriod, e.ActiveAt.Add(alertForDuration).Sub(restoreTime))
 			}
-		} else {
+		default:
 			exp := tst.alerts
 			require.Equal(t, len(exp), len(got))
 			sortAlerts(exp)
--- a/rules/recording_test.go
+++ b/rules/recording_test.go
@ -223,10 +223,10 @@ func TestRecordingRuleLimit(t *testing.T) {
 	evalTime := time.Unix(0, 0)

 	for _, test := range tests {
-		_, err := rule.Eval(suite.Context(), evalTime, EngineQueryFunc(suite.QueryEngine(), suite.Storage()), nil, test.limit)
-		if err != nil {
+		switch _, err := rule.Eval(suite.Context(), evalTime, EngineQueryFunc(suite.QueryEngine(), suite.Storage()), nil, test.limit); {
+		case err != nil:
 			require.EqualError(t, err, test.err)
-		} else if test.err != "" {
+		case test.err != "":
 			t.Errorf("Expected error %s, got none", test.err)
 		}
 	}
--- a/scrape/manager.go
+++ b/scrape/manager.go
@ -288,10 +288,11 @@ func (m *Manager) ApplyConfig(cfg *config.Config) error {
 	// Cleanup and reload pool if the configuration has changed.
 	var failed bool
 	for name, sp := range m.scrapePools {
-		if cfg, ok := m.scrapeConfigs[name]; !ok {
+		switch cfg, ok := m.scrapeConfigs[name]; {
+		case !ok:
 			sp.stop()
 			delete(m.scrapePools, name)
-		} else if !reflect.DeepEqual(sp.config, cfg) {
+		case !reflect.DeepEqual(sp.config, cfg):
 			err := sp.reload(cfg)
 			if err != nil {
 				level.Error(m.logger).Log("msg", "error reloading scrape pool", "err", err, "scrape_pool", name)
--- a/scrape/scrape.go
+++ b/scrape/scrape.go
@ -503,9 +503,10 @@ func (sp *scrapePool) Sync(tgs []*targetgroup.Group) {
 			// Replicate .Labels().IsEmpty() with a loop here to avoid generating garbage.
 			nonEmpty := false
 			t.LabelsRange(func(l labels.Label) { nonEmpty = true })
-			if nonEmpty {
+			switch {
+			case nonEmpty:
 				all = append(all, t)
-			} else if !t.discoveredLabels.IsEmpty() {
+			case !t.discoveredLabels.IsEmpty():
 				sp.droppedTargets = append(sp.droppedTargets, t)
 			}
 		}
@ -946,9 +947,10 @@ func (c *scrapeCache) iterDone(flushCache bool) {
 	count := len(c.series) + len(c.droppedSeries) + len(c.metadata)
 	c.metaMtx.Unlock()

-	if flushCache {
+	switch {
+	case flushCache:
 		c.successfulCount = count
-	} else if count > c.successfulCount*2+1000 {
+	case count > c.successfulCount*2+1000:
 		// If a target had varying labels in scrapes that ultimately failed,
 		// the caches would grow indefinitely. Force a flush when this happens.
 		// We use the heuristic that this is a doubling of the cache size
--- a/scrape/scrape_test.go
+++ b/scrape/scrape_test.go
@ -724,9 +724,10 @@ func TestScrapeLoopStop(t *testing.T) {
 	// All samples in a scrape must have the same timestamp.
 	var ts int64
 	for i, s := range appender.result {
-		if i%6 == 0 {
+		switch {
+		case i%6 == 0:
 			ts = s.t
-		} else if s.t != ts {
+		case s.t != ts:
 			t.Fatalf("Unexpected multiple timestamps within single scrape")
 		}
 	}
@ -1139,10 +1140,11 @@ func TestScrapeLoopRunCreatesStaleMarkersOnFailedScrape(t *testing.T) {
 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
 		numScrapes++

-		if numScrapes == 1 {
+		switch numScrapes {
+		case 1:
 			w.Write([]byte("metric_a 42\n"))
 			return nil
-		} else if numScrapes == 5 {
+		case 5:
 			cancel()
 		}
 		return errors.New("scrape failed")
@ -1200,13 +1202,14 @@ func TestScrapeLoopRunCreatesStaleMarkersOnParseFailure(t *testing.T) {
 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
 		numScrapes++

-		if numScrapes == 1 {
+		switch numScrapes {
+		case 1:
 			w.Write([]byte("metric_a 42\n"))
 			return nil
-		} else if numScrapes == 2 {
+		case 2:
 			w.Write([]byte("7&-\n"))
 			return nil
-		} else if numScrapes == 3 {
+		case 3:
 			cancel()
 		}
 		return errors.New("scrape failed")
@ -1265,14 +1268,15 @@ func TestScrapeLoopCache(t *testing.T) {
 	numScrapes := 0

 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
-		if numScrapes == 1 || numScrapes == 2 {
+		switch numScrapes {
+		case 1, 2:
 			if _, ok := sl.cache.series["metric_a"]; !ok {
 				t.Errorf("metric_a missing from cache after scrape %d", numScrapes)
 			}
 			if _, ok := sl.cache.series["metric_b"]; !ok {
 				t.Errorf("metric_b missing from cache after scrape %d", numScrapes)
 			}
-		} else if numScrapes == 3 {
+		case 3:
 			if _, ok := sl.cache.series["metric_a"]; !ok {
 				t.Errorf("metric_a missing from cache after scrape %d", numScrapes)
 			}
@ -1283,13 +1287,14 @@ func TestScrapeLoopCache(t *testing.T) {

 		numScrapes++

-		if numScrapes == 1 {
+		switch numScrapes {
+		case 1:
 			w.Write([]byte("metric_a 42\nmetric_b 43\n"))
 			return nil
-		} else if numScrapes == 3 {
+		case 3:
 			w.Write([]byte("metric_a 44\n"))
 			return nil
-		} else if numScrapes == 4 {
+		case 4:
 			cancel()
 		}
 		return fmt.Errorf("scrape failed")
@ -2280,11 +2285,12 @@ func TestTargetScrapeScrapeCancel(t *testing.T) {

 	go func() {
 		_, err := ts.scrape(ctx, io.Discard)
-		if err == nil {
+		switch {
+		case err == nil:
 			errc <- errors.New("Expected error but got nil")
-		} else if ctx.Err() != context.Canceled {
+		case ctx.Err() != context.Canceled:
 			errc <- errors.Errorf("Expected context cancellation error but got: %s", ctx.Err())
-		} else {
+		default:
 			close(errc)
 		}
 	}()
--- a/storage/fanout.go
+++ b/storage/fanout.go
@ -222,9 +222,10 @@ func (f *fanoutAppender) Rollback() (err error) {

 	for _, appender := range f.secondaries {
 		rollbackErr := appender.Rollback()
-		if err == nil {
+		switch {
+		case err == nil:
 			err = rollbackErr
-		} else if rollbackErr != nil {
+		case rollbackErr != nil:
 			level.Error(f.logger).Log("msg", "Squashed rollback error on rollback", "err", rollbackErr)
 		}
 	}
--- a/storage/merge.go
+++ b/storage/merge.go
@ -197,13 +197,14 @@ func mergeStrings(a, b []string) []string {
 	res := make([]string, 0, maxl*10/9)

 	for len(a) > 0 && len(b) > 0 {
-		if a[0] == b[0] {
+		switch {
+		case a[0] == b[0]:
 			res = append(res, a[0])
 			a, b = a[1:], b[1:]
-		} else if a[0] < b[0] {
+		case a[0] < b[0]:
 			res = append(res, a[0])
 			a = a[1:]
-		} else {
+		default:
 			res = append(res, b[0])
 			b = b[1:]
 		}
--- a/storage/remote/codec.go
+++ b/storage/remote/codec.go
@ -291,13 +291,14 @@ func MergeLabels(primary, secondary []prompb.Label) []prompb.Label {
 	result := make([]prompb.Label, 0, len(primary)+len(secondary))
 	i, j := 0, 0
 	for i < len(primary) && j < len(secondary) {
-		if primary[i].Name < secondary[j].Name {
+		switch {
+		case primary[i].Name < secondary[j].Name:
 			result = append(result, primary[i])
 			i++
-		} else if primary[i].Name > secondary[j].Name {
+		case primary[i].Name > secondary[j].Name:
 			result = append(result, secondary[j])
 			j++
-		} else {
+		default:
 			result = append(result, primary[i])
 			i++
 			j++
@ -429,7 +430,8 @@ func (c *concreteSeriesIterator) Seek(t int64) chunkenc.ValueType {
 		return c.series.histograms[n+c.histogramsCur].Timestamp >= t
 	})

-	if c.floatsCur < len(c.series.floats) && c.histogramsCur < len(c.series.histograms) {
+	switch {
+	case c.floatsCur < len(c.series.floats) && c.histogramsCur < len(c.series.histograms):
 		// If float samples and histogram samples have overlapping timestamps prefer the float samples.
 		if c.series.floats[c.floatsCur].Timestamp <= c.series.histograms[c.histogramsCur].Timestamp {
 			c.curValType = chunkenc.ValFloat
@ -445,9 +447,9 @@ func (c *concreteSeriesIterator) Seek(t int64) chunkenc.ValueType {
 				c.floatsCur--
 			}
 		}
-	} else if c.floatsCur < len(c.series.floats) {
+	case c.floatsCur < len(c.series.floats):
 		c.curValType = chunkenc.ValFloat
-	} else if c.histogramsCur < len(c.series.histograms) {
+	case c.histogramsCur < len(c.series.histograms):
 		c.curValType = getHistogramValType(&c.series.histograms[c.histogramsCur])
 	}

@ -515,18 +517,19 @@ func (c *concreteSeriesIterator) Next() chunkenc.ValueType {
 	}
 	c.curValType = chunkenc.ValNone

-	if peekFloatTS < peekHistTS {
+	switch {
+	case peekFloatTS < peekHistTS:
 		c.floatsCur++
 		c.curValType = chunkenc.ValFloat
-	} else if peekHistTS < peekFloatTS {
+	case peekHistTS < peekFloatTS:
 		c.histogramsCur++
 		c.curValType = chunkenc.ValHistogram
-	} else if peekFloatTS == noTS && peekHistTS == noTS {
+	case peekFloatTS == noTS && peekHistTS == noTS:
 		// This only happens when the iterator is exhausted; we set the cursors off the end to prevent
 		// Seek() from returning anything afterwards.
 		c.floatsCur = len(c.series.floats)
 		c.histogramsCur = len(c.series.histograms)
-	} else {
+	default:
 		// Prefer float samples to histogram samples if there's a conflict. We advance the cursor for histograms
 		// anyway otherwise the histogram sample will get selected on the next call to Next().
 		c.floatsCur++
--- a/storage/remote/ewma.go
+++ b/storage/remote/ewma.go
@ -55,9 +55,10 @@ func (r *ewmaRate) tick() {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

-	if r.init {
+	switch {
+	case r.init:
 		r.lastRate += r.alpha * (instantRate - r.lastRate)
-	} else if newEvents > 0 {
+	case newEvents > 0:
 		r.init = true
 		r.lastRate = instantRate
 	}
--- a/storage/remote/queue_manager.go
+++ b/storage/remote/queue_manager.go
@ -1030,9 +1030,10 @@ func (t *QueueManager) calculateDesiredShards() int {
 		return t.numShards
 	}

-	if numShards > t.cfg.MaxShards {
+	switch {
+	case numShards > t.cfg.MaxShards:
 		numShards = t.cfg.MaxShards
-	} else if numShards < t.cfg.MinShards {
+	case numShards < t.cfg.MinShards:
 		numShards = t.cfg.MinShards
 	}
 	return numShards
@ -1575,10 +1576,11 @@ func sendWriteRequestWithBackoff(ctx context.Context, cfg config.QueueConfig, l
 		}

 		sleepDuration = backoff
-		if backoffErr.retryAfter > 0 {
+		switch {
+		case backoffErr.retryAfter > 0:
 			sleepDuration = backoffErr.retryAfter
 			level.Info(l).Log("msg", "Retrying after duration specified by Retry-After header", "duration", sleepDuration)
-		} else if backoffErr.retryAfter < 0 {
+		case backoffErr.retryAfter < 0:
 			level.Debug(l).Log("msg", "retry-after cannot be in past, retrying using default backoff mechanism")
 		}

--- a/tsdb/agent/db.go
+++ b/tsdb/agent/db.go
@ -951,7 +951,8 @@ func (a *appender) AppendHistogram(ref storage.SeriesRef, l labels.Labels, t int
 		return 0, storage.ErrOutOfOrderSample
 	}

-	if h != nil {
+	switch {
+	case h != nil:
 		// NOTE: always modify pendingHistograms and histogramSeries together
 		a.pendingHistograms = append(a.pendingHistograms, record.RefHistogramSample{
 			Ref: series.ref,
@ -959,7 +960,7 @@ func (a *appender) AppendHistogram(ref storage.SeriesRef, l labels.Labels, t int
 			H:   h,
 		})
 		a.histogramSeries = append(a.histogramSeries, series)
-	} else if fh != nil {
+	case fh != nil:
 		// NOTE: always modify pendingFloatHistograms and floatHistogramSeries together
 		a.pendingFloatHistograms = append(a.pendingFloatHistograms, record.RefFloatHistogramSample{
 			Ref: series.ref,
--- a/tsdb/chunkenc/xor.go
+++ b/tsdb/chunkenc/xor.go
@ -164,14 +164,15 @@ func (a *xorAppender) Append(t int64, v float64) {
 	var tDelta uint64
 	num := binary.BigEndian.Uint16(a.b.bytes())

-	if num == 0 {
+	switch num {
+	case 0:
 		buf := make([]byte, binary.MaxVarintLen64)
 		for _, b := range buf[:binary.PutVarint(buf, t)] {
 			a.b.writeByte(b)
 		}
 		a.b.writeBits(math.Float64bits(v), 64)

-	} else if num == 1 {
+	case 1:
 		tDelta = uint64(t - a.t)

 		buf := make([]byte, binary.MaxVarintLen64)
@ -181,7 +182,7 @@ func (a *xorAppender) Append(t int64, v float64) {

 		a.writeVDelta(v)

-	} else {
+	default:
 		tDelta = uint64(t - a.t)
 		dod := int64(tDelta - a.tDelta)

--- a/tsdb/chunks/head_chunks.go
+++ b/tsdb/chunks/head_chunks.go
@ -999,9 +999,10 @@ func (cdm *ChunkDiskMapper) DeleteCorrupted(originalErr error) error {
 	cdm.readPathMtx.RLock()
 	lastSeq := 0
 	for seg := range cdm.mmappedChunkFiles {
-		if seg >= cerr.FileIndex {
+		switch {
+		case seg >= cerr.FileIndex:
 			segs = append(segs, seg)
-		} else if seg > lastSeq {
+		case seg > lastSeq:
 			lastSeq = seg
 		}
 	}
--- a/tsdb/db.go
+++ b/tsdb/db.go
@ -963,10 +963,11 @@ func (db *DB) ApplyConfig(conf *config.Config) error {
 	// Create WBL if it was not present and if OOO is enabled with WAL enabled.
 	var wblog *wlog.WL
 	var err error
-	if db.head.wbl != nil {
+	switch {
+	case db.head.wbl != nil:
 		// The existing WBL from the disk might have been replayed while OOO was disabled.
 		wblog = db.head.wbl
-	} else if !db.oooWasEnabled.Load() && oooTimeWindow > 0 && db.opts.WALSegmentSize >= 0 {
+	case !db.oooWasEnabled.Load() && oooTimeWindow > 0 && db.opts.WALSegmentSize >= 0:
 		segmentSize := wlog.DefaultSegmentSize
 		// Wal is set to a custom size.
 		if db.opts.WALSegmentSize > 0 {
@ -1532,10 +1533,11 @@ func (db *DB) deleteBlocks(blocks map[ulid.ULID]*Block) error {
 		}

 		toDelete := filepath.Join(db.dir, ulid.String())
-		if _, err := os.Stat(toDelete); os.IsNotExist(err) {
+		switch _, err := os.Stat(toDelete); {
+		case os.IsNotExist(err):
 			// Noop.
 			continue
-		} else if err != nil {
+		case err != nil:
 			return errors.Wrapf(err, "stat dir %v", toDelete)
 		}

--- a/tsdb/head_append.go
+++ b/tsdb/head_append.go
@ -344,9 +344,10 @@ func (a *headAppender) Append(ref storage.SeriesRef, lset labels.Labels, t int64
 	}

 	if value.IsStaleNaN(v) {
-		if s.lastHistogramValue != nil {
+		switch {
+		case s.lastHistogramValue != nil:
 			return a.AppendHistogram(ref, lset, t, &histogram.Histogram{Sum: v}, nil)
-		} else if s.lastFloatHistogramValue != nil {
+		case s.lastFloatHistogramValue != nil:
 			return a.AppendHistogram(ref, lset, t, nil, &histogram.FloatHistogram{Sum: v})
 		}
 	}
@ -552,9 +553,10 @@ func (a *headAppender) AppendHistogram(ref storage.SeriesRef, lset labels.Labels
 			return 0, err
 		}
 		if created {
-			if h != nil {
+			switch {
+			case h != nil:
 				s.lastHistogramValue = &histogram.Histogram{}
-			} else if fh != nil {
+			case fh != nil:
 				s.lastFloatHistogramValue = &histogram.FloatHistogram{}
 			}
 			a.series = append(a.series, record.RefSeries{
@ -564,7 +566,8 @@ func (a *headAppender) AppendHistogram(ref storage.SeriesRef, lset labels.Labels
 		}
 	}

-	if h != nil {
+	switch {
+	case h != nil:
 		s.Lock()
 		if err := s.appendableHistogram(t, h); err != nil {
 			s.Unlock()
@ -581,7 +584,7 @@ func (a *headAppender) AppendHistogram(ref storage.SeriesRef, lset labels.Labels
 			H:   h,
 		})
 		a.histogramSeries = append(a.histogramSeries, s)
-	} else if fh != nil {
+	case fh != nil:
 		s.Lock()
 		if err := s.appendableFloatHistogram(t, fh); err != nil {
 			s.Unlock()
@ -938,7 +941,10 @@ func (a *headAppender) Commit() (err error) {

 		var ok, chunkCreated bool

-		if err == nil && oooSample {
+		switch {
+		case err != nil:
+			// Do nothing here.
+		case oooSample:
 			// Sample is OOO and OOO handling is enabled
 			// and the delta is within the OOO tolerance.
 			var mmapRef chunks.ChunkDiskMapperRef
@ -976,7 +982,7 @@ func (a *headAppender) Commit() (err error) {
 				// TODO(codesome): Add error reporting? It depends on addressing https://github.com/prometheus/prometheus/discussions/10305.
 				samplesAppended--
 			}
-		} else if err == nil {
+		default:
 			ok, chunkCreated = series.append(s.T, s.V, a.appendID, a.head.chunkDiskMapper, chunkRange)
 			if ok {
 				if s.T < inOrderMint {
@ -1177,14 +1183,15 @@ func (s *memSeries) appendHistogram(t int64, h *histogram.Histogram, appendID ui
 			app.RecodeHistogram(h, pBackwardInserts, nBackwardInserts)
 		}
 		// We have 3 cases here
-		// - !okToAppend -> We need to cut a new chunk.
+		// - !okToAppend or counterReset -> We need to cut a new chunk.
 		// - okToAppend but we have inserts → Existing chunk needs
 		//   recoding before we can append our histogram.
 		// - okToAppend and no inserts → Chunk is ready to support our histogram.
-		if !okToAppend || counterReset {
+		switch {
+		case !okToAppend || counterReset:
 			c = s.cutNewHeadChunk(t, chunkenc.EncHistogram, chunkDiskMapper, chunkRange)
 			chunkCreated = true
-		} else if len(pForwardInserts) > 0 || len(nForwardInserts) > 0 {
+		case len(pForwardInserts) > 0 || len(nForwardInserts) > 0:
 			// New buckets have appeared. We need to recode all
 			// prior histogram samples within the chunk before we
 			// can process this one.
@ -1270,14 +1277,15 @@ func (s *memSeries) appendFloatHistogram(t int64, fh *histogram.FloatHistogram,
 			app.RecodeHistogramm(fh, pBackwardInserts, nBackwardInserts)
 		}
 		// We have 3 cases here
-		// - !okToAppend -> We need to cut a new chunk.
+		// - !okToAppend or counterReset -> We need to cut a new chunk.
 		// - okToAppend but we have inserts → Existing chunk needs
 		//   recoding before we can append our histogram.
 		// - okToAppend and no inserts → Chunk is ready to support our histogram.
-		if !okToAppend || counterReset {
+		switch {
+		case !okToAppend || counterReset:
 			c = s.cutNewHeadChunk(t, chunkenc.EncFloatHistogram, chunkDiskMapper, chunkRange)
 			chunkCreated = true
-		} else if len(pForwardInserts) > 0 || len(nForwardInserts) > 0 {
+		case len(pForwardInserts) > 0 || len(nForwardInserts) > 0:
 			// New buckets have appeared. We need to recode all
 			// prior histogram samples within the chunk before we
 			// can process this one.
--- a/tsdb/head_read.go
+++ b/tsdb/head_read.go
@ -424,7 +424,8 @@ func (s *memSeries) oooMergedChunk(meta chunks.Meta, cdm *chunks.ChunkDiskMapper
 			break
 		}

-		if chunkRef == meta.OOOLastRef {
+		switch {
+		case chunkRef == meta.OOOLastRef:
 			tmpChks = append(tmpChks, chunkMetaAndChunkDiskMapperRef{
 				meta: chunks.Meta{
 					MinTime: meta.OOOLastMinTime,
@ -435,7 +436,7 @@ func (s *memSeries) oooMergedChunk(meta chunks.Meta, cdm *chunks.ChunkDiskMapper
 				origMinT: c.minTime,
 				origMaxT: c.maxTime,
 			})
-		} else if c.OverlapsClosedInterval(mint, maxt) {
+		case c.OverlapsClosedInterval(mint, maxt):
 			tmpChks = append(tmpChks, chunkMetaAndChunkDiskMapperRef{
 				meta: chunks.Meta{
 					MinTime: c.minTime,
@ -594,12 +595,14 @@ type boundedIterator struct {
 func (b boundedIterator) Next() chunkenc.ValueType {
 	for b.Iterator.Next() == chunkenc.ValFloat {
 		t, _ := b.Iterator.At()
-		if t < b.minT {
+		switch {
+		case t < b.minT:
 			continue
-		} else if t > b.maxT {
+		case t > b.maxT:
 			return chunkenc.ValNone
+		default:
+			return chunkenc.ValFloat
 		}
-		return chunkenc.ValFloat
 	}
 	return chunkenc.ValNone
 }
--- a/tsdb/head_test.go
+++ b/tsdb/head_test.go
@ -2960,10 +2960,11 @@ func TestAppendHistogram(t *testing.T) {
 			actHistograms := make([]tsdbutil.Sample, 0, len(expHistograms))
 			actFloatHistograms := make([]tsdbutil.Sample, 0, len(expFloatHistograms))
 			for typ := it.Next(); typ != chunkenc.ValNone; typ = it.Next() {
-				if typ == chunkenc.ValHistogram {
+				switch typ {
+				case chunkenc.ValHistogram:
 					ts, h := it.AtHistogram()
 					actHistograms = append(actHistograms, sample{t: ts, h: h})
-				} else if typ == chunkenc.ValFloatHistogram {
+				case chunkenc.ValFloatHistogram:
 					ts, fh := it.AtFloatHistogram()
 					actFloatHistograms = append(actFloatHistograms, sample{t: ts, fh: fh})
 				}
@ -3565,14 +3566,15 @@ func testHistogramStaleSampleHelper(t *testing.T, floatHistogram bool) {
 		for i, eh := range expHistograms {
 			ah := actHistograms[i]
 			if floatHistogram {
-				if value.IsStaleNaN(eh.fh.Sum) {
+				switch {
+				case value.IsStaleNaN(eh.fh.Sum):
 					actNumStale++
 					require.True(t, value.IsStaleNaN(ah.fh.Sum))
 					// To make require.Equal work.
 					ah.fh.Sum = 0
 					eh.fh = eh.fh.Copy()
 					eh.fh.Sum = 0
-				} else if i > 0 {
+				case i > 0:
 					prev := expHistograms[i-1]
 					if prev.fh == nil || value.IsStaleNaN(prev.fh.Sum) {
 						eh.fh.CounterResetHint = histogram.UnknownCounterReset
@ -3580,14 +3582,15 @@ func testHistogramStaleSampleHelper(t *testing.T, floatHistogram bool) {
 				}
 				require.Equal(t, eh, ah)
 			} else {
-				if value.IsStaleNaN(eh.h.Sum) {
+				switch {
+				case value.IsStaleNaN(eh.h.Sum):
 					actNumStale++
 					require.True(t, value.IsStaleNaN(ah.h.Sum))
 					// To make require.Equal work.
 					ah.h.Sum = 0
 					eh.h = eh.h.Copy()
 					eh.h.Sum = 0
-				} else if i > 0 {
+				case i > 0:
 					prev := expHistograms[i-1]
 					if prev.h == nil || value.IsStaleNaN(prev.h.Sum) {
 						eh.h.CounterResetHint = histogram.UnknownCounterReset
@ -4488,19 +4491,19 @@ func TestHistogramValidation(t *testing.T) {

 	for testName, tc := range tests {
 		t.Run(testName, func(t *testing.T) {
-			err := ValidateHistogram(tc.h)
-			if tc.errMsg != "" {
+			switch err := ValidateHistogram(tc.h); {
+			case tc.errMsg != "":
 				require.ErrorContains(t, err, tc.errMsg)
-			} else {
+			default:
 				require.NoError(t, err)
 			}

-			err = ValidateFloatHistogram(tc.h.ToFloat())
-			if tc.errMsgFloat != "" {
+			switch err := ValidateFloatHistogram(tc.h.ToFloat()); {
+			case tc.errMsgFloat != "":
 				require.ErrorContains(t, err, tc.errMsgFloat)
-			} else if tc.errMsg != "" {
+			case tc.errMsg != "":
 				require.ErrorContains(t, err, tc.errMsg)
-			} else {
+			default:
 				require.NoError(t, err)
 			}
 		})
--- a/tsdb/index/postings.go
+++ b/tsdb/index/postings.go
@ -565,12 +565,11 @@ func newMergedPostings(p []Postings) (m *mergedPostings, nonEmpty bool) {

 	for _, it := range p {
 		// NOTE: mergedPostings struct requires the user to issue an initial Next.
-		if it.Next() {
+		switch {
+		case it.Next():
 			ph = append(ph, it)
-		} else {
-			if it.Err() != nil {
-				return &mergedPostings{err: it.Err()}, true
-			}
+		case it.Err() != nil:
+			return &mergedPostings{err: it.Err()}, true
 		}
 	}

@ -704,16 +703,16 @@ func (rp *removedPostings) Next() bool {
 			return true
 		}

-		fcur, rcur := rp.full.At(), rp.remove.At()
-		if fcur < rcur {
+		switch fcur, rcur := rp.full.At(), rp.remove.At(); {
+		case fcur < rcur:
 			rp.cur = fcur
 			rp.fok = rp.full.Next()

 			return true
-		} else if rcur < fcur {
+		case rcur < fcur:
 			// Forward the remove postings to the right position.
 			rp.rok = rp.remove.Seek(fcur)
-		} else {
+		default:
 			// Skip the current posting.
 			rp.fok = rp.full.Next()
 		}
@ -848,9 +847,10 @@ func (it *bigEndianPostings) Err() error {
 func FindIntersectingPostings(p Postings, candidates []Postings) (indexes []int, err error) {
 	h := make(postingsWithIndexHeap, 0, len(candidates))
 	for idx, it := range candidates {
-		if it.Next() {
+		switch {
+		case it.Next():
 			h = append(h, postingsWithIndex{index: idx, p: it})
-		} else if it.Err() != nil {
+		case it.Err() != nil:
 			return nil, it.Err()
 		}
 	}
--- a/tsdb/ooo_head_read.go
+++ b/tsdb/ooo_head_read.go
@ -123,7 +123,7 @@ func (oh *OOOHeadIndexReader) series(ref storage.SeriesRef, builder *labels.Scra
 		}
 	}

-	// There is nothing to do if we did not collect any chunk
+	// There is nothing to do if we did not collect any chunk.
 	if len(tmpChks) == 0 {
 		return nil
 	}
@ -136,14 +136,15 @@ func (oh *OOOHeadIndexReader) series(ref storage.SeriesRef, builder *labels.Scra
 	// chunks Meta the first chunk that overlaps with others.
 	// Example chunks of a series: 5:(100, 200) 6:(500, 600) 7:(150, 250) 8:(550, 650)
 	// In the example 5 overlaps with 7 and 6 overlaps with 8 so we only want to
-	// to return chunk Metas for chunk 5 and chunk 6
+	// to return chunk Metas for chunk 5 and chunk 6e
 	*chks = append(*chks, tmpChks[0])
-	maxTime := tmpChks[0].MaxTime // tracks the maxTime of the previous "to be merged chunk"
+	maxTime := tmpChks[0].MaxTime // Tracks the maxTime of the previous "to be merged chunk".
 	for _, c := range tmpChks[1:] {
-		if c.MinTime > maxTime {
+		switch {
+		case c.MinTime > maxTime:
 			*chks = append(*chks, c)
 			maxTime = c.MaxTime
-		} else if c.MaxTime > maxTime {
+		case c.MaxTime > maxTime:
 			maxTime = c.MaxTime
 			(*chks)[len(*chks)-1].MaxTime = c.MaxTime
 		}
--- a/tsdb/querier.go
+++ b/tsdb/querier.go
@ -239,18 +239,20 @@ func PostingsForMatchers(ix IndexReader, ms ...*labels.Matcher) (index.Postings,
 	}

 	for _, m := range ms {
-		if m.Name == "" && m.Value == "" { // Special-case for AllPostings, used in tests at least.
+		switch {
+		case m.Name == "" && m.Value == "": // Special-case for AllPostings, used in tests at least.
 			k, v := index.AllPostingsKey()
 			allPostings, err := ix.Postings(k, v)
 			if err != nil {
 				return nil, err
 			}
 			its = append(its, allPostings)
-		} else if labelMustBeSet[m.Name] {
+		case labelMustBeSet[m.Name]:
 			// If this matcher must be non-empty, we can be smarter.
 			matchesEmpty := m.Matches("")
 			isNot := m.Type == labels.MatchNotEqual || m.Type == labels.MatchNotRegexp
-			if isNot && matchesEmpty { // l!="foo"
+			switch {
+			case isNot && matchesEmpty: // l!="foo"
 				// If the label can't be empty and is a Not and the inner matcher
 				// doesn't match empty, then subtract it out at the end.
 				inverse, err := m.Inverse()
@ -263,7 +265,7 @@ func PostingsForMatchers(ix IndexReader, ms ...*labels.Matcher) (index.Postings,
 					return nil, err
 				}
 				notIts = append(notIts, it)
-			} else if isNot && !matchesEmpty { // l!=""
+			case isNot && !matchesEmpty: // l!=""
 				// If the label can't be empty and is a Not, but the inner matcher can
 				// be empty we need to use inversePostingsForMatcher.
 				inverse, err := m.Inverse()
@ -279,7 +281,7 @@ func PostingsForMatchers(ix IndexReader, ms ...*labels.Matcher) (index.Postings,
 					return index.EmptyPostings(), nil
 				}
 				its = append(its, it)
-			} else { // l="a"
+			default: // l="a"
 				// Non-Not matcher, use normal postingsForMatcher.
 				it, err := postingsForMatcher(ix, m)
 				if err != nil {
@ -290,7 +292,7 @@ func PostingsForMatchers(ix IndexReader, ms ...*labels.Matcher) (index.Postings,
 				}
 				its = append(its, it)
 			}
-		} else { // l=""
+		default: // l=""
 			// If the matchers for a labelname selects an empty value, it selects all
 			// the series which don't have the label name set too. See:
 			// https://github.com/prometheus/prometheus/issues/3575 and
@ -966,23 +968,24 @@ func (m *mergedStringIter) Next() bool {
 		return false
 	}

-	if !m.aok {
+	switch {
+	case !m.aok:
 		m.cur = m.b.At()
 		m.bok = m.b.Next()
 		m.err = m.b.Err()
-	} else if !m.bok {
+	case !m.bok:
 		m.cur = m.a.At()
 		m.aok = m.a.Next()
 		m.err = m.a.Err()
-	} else if m.b.At() > m.a.At() {
+	case m.b.At() > m.a.At():
 		m.cur = m.a.At()
 		m.aok = m.a.Next()
 		m.err = m.a.Err()
-	} else if m.a.At() > m.b.At() {
+	case m.a.At() > m.b.At():
 		m.cur = m.b.At()
 		m.bok = m.b.Next()
 		m.err = m.b.Err()
-	} else { // Equal.
+	default: // Equal.
 		m.cur = m.b.At()
 		m.aok = m.a.Next()
 		m.err = m.a.Err()
--- a/tsdb/tombstones/tombstones.go
+++ b/tsdb/tombstones/tombstones.go
@ -190,9 +190,10 @@ type Stone struct {

 func ReadTombstones(dir string) (Reader, int64, error) {
 	b, err := os.ReadFile(filepath.Join(dir, TombstonesFilename))
-	if os.IsNotExist(err) {
+	switch {
+	case os.IsNotExist(err):
 		return NewMemTombstones(), 0, nil
-	} else if err != nil {
+	case err != nil:
 		return nil, 0, err
 	}

--- a/tsdb/wal.go
+++ b/tsdb/wal.go
@ -522,9 +522,10 @@ func (w *SegmentWAL) openSegmentFile(name string) (*os.File, error) {
 		}
 	}()

-	if n, err := f.Read(metab); err != nil {
+	switch n, err := f.Read(metab); {
+	case err != nil:
 		return nil, errors.Wrapf(err, "validate meta %q", f.Name())
-	} else if n != 8 {
+	case n != 8:
 		return nil, errors.Errorf("invalid header size %d in %q", n, f.Name())
 	}

@ -1063,9 +1064,10 @@ func (r *walReader) entry(cr io.Reader) (WALEntryType, byte, []byte, error) {
 	tr := io.TeeReader(cr, r.crc32)

 	b := make([]byte, 6)
-	if n, err := tr.Read(b); err != nil {
+	switch n, err := tr.Read(b); {
+	case err != nil:
 		return 0, 0, nil, err
-	} else if n != 6 {
+	case n != 6:
 		return 0, 0, nil, r.corruptionErr("invalid entry header size %d", n)
 	}

@ -1087,15 +1089,17 @@ func (r *walReader) entry(cr io.Reader) (WALEntryType, byte, []byte, error) {
 	}
 	buf := r.buf[:length]

-	if n, err := tr.Read(buf); err != nil {
+	switch n, err := tr.Read(buf); {
+	case err != nil:
 		return 0, 0, nil, err
-	} else if n != length {
+	case n != length:
 		return 0, 0, nil, r.corruptionErr("invalid entry body size %d", n)
 	}

-	if n, err := cr.Read(b[:4]); err != nil {
+	switch n, err := cr.Read(b[:4]); {
+	case err != nil:
 		return 0, 0, nil, err
-	} else if n != 4 {
+	case n != 4:
 		return 0, 0, nil, r.corruptionErr("invalid checksum length %d", n)
 	}
 	if exp, has := binary.BigEndian.Uint32(b[:4]), r.crc32.Sum32(); has != exp {
--- a/tsdb/wlog/live_reader.go
+++ b/tsdb/wlog/live_reader.go
@ -126,9 +126,10 @@ func (r *LiveReader) Next() bool {
 		// we return  EOF and the user can try again later. If we have a full
 		// page, buildRecord is guaranteed to return a record or a non-EOF; it
 		// has checks the records fit in pages.
-		if ok, err := r.buildRecord(); ok {
+		switch ok, err := r.buildRecord(); {
+		case ok:
 			return true
-		} else if err != nil && err != io.EOF {
+		case err != nil && err != io.EOF:
 			r.err = err
 			return false
 		}
--- a/tsdb/wlog/watcher.go
+++ b/tsdb/wlog/watcher.go
@ -405,9 +405,10 @@ func (w *Watcher) watch(segmentNum int, tail bool) error {

 			// Ignore errors reading to end of segment whilst replaying the WAL.
 			if !tail {
-				if err != nil && errors.Cause(err) != io.EOF {
+				switch {
+				case err != nil && errors.Cause(err) != io.EOF:
 					level.Warn(w.logger).Log("msg", "Ignoring error reading to end of segment, may have dropped data", "err", err)
-				} else if reader.Offset() != size {
+				case reader.Offset() != size:
 					level.Warn(w.logger).Log("msg", "Expected to have read whole segment, may have dropped data", "segment", segmentNum, "read", reader.Offset(), "size", size)
 				}
 				return nil
@ -425,9 +426,10 @@ func (w *Watcher) watch(segmentNum int, tail bool) error {

 			// Ignore all errors reading to end of segment whilst replaying the WAL.
 			if !tail {
-				if err != nil && errors.Cause(err) != io.EOF {
+				switch {
+				case err != nil && errors.Cause(err) != io.EOF:
 					level.Warn(w.logger).Log("msg", "Ignoring error reading to end of segment, may have dropped data", "segment", segmentNum, "err", err)
-				} else if reader.Offset() != size {
+				case reader.Offset() != size:
 					level.Warn(w.logger).Log("msg", "Expected to have read whole segment, may have dropped data", "segment", segmentNum, "read", reader.Offset(), "size", size)
 				}
 				return nil
--- a/util/treecache/treecache.go
+++ b/util/treecache/treecache.go
@ -176,11 +176,11 @@ func (tc *ZookeeperTreeCache) loop(path string) {
 					node = childNode
 				}

-				err := tc.recursiveNodeUpdate(ev.Path, node)
-				if err != nil {
+				switch err := tc.recursiveNodeUpdate(ev.Path, node); {
+				case err != nil:
 					level.Error(tc.logger).Log("msg", "Error during processing of Zookeeper event", "err", err)
 					failure()
-				} else if tc.head.data == nil {
+				case tc.head.data == nil:
 					level.Error(tc.logger).Log("msg", "Error during processing of Zookeeper event", "err", "path no longer exists", "path", tc.prefix)
 					failure()
 				}
@ -214,13 +214,14 @@ func (tc *ZookeeperTreeCache) loop(path string) {

 func (tc *ZookeeperTreeCache) recursiveNodeUpdate(path string, node *zookeeperTreeCacheNode) error {
 	data, _, dataWatcher, err := tc.conn.GetW(path)
-	if errors.Is(err, zk.ErrNoNode) {
+	switch {
+	case errors.Is(err, zk.ErrNoNode):
 		tc.recursiveDelete(path, node)
 		if node == tc.head {
 			return fmt.Errorf("path %s does not exist", path)
 		}
 		return nil
-	} else if err != nil {
+	case err != nil:
 		return err
 	}

@ -230,10 +231,11 @@ func (tc *ZookeeperTreeCache) recursiveNodeUpdate(path string, node *zookeeperTr
 	}

 	children, _, childWatcher, err := tc.conn.ChildrenW(path)
-	if errors.Is(err, zk.ErrNoNode) {
+	switch {
+	case errors.Is(err, zk.ErrNoNode):
 		tc.recursiveDelete(path, node)
 		return nil
-	} else if err != nil {
+	case err != nil:
 		return err
 	}

--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@ -989,12 +989,14 @@ func (api *API) targets(r *http.Request) apiFuncResult {
 					ScrapeURL:        target.URL().String(),
 					GlobalURL:        globalURL.String(),
 					LastError: func() string {
-						if err == nil && lastErrStr == "" {
+						switch {
+						case err == nil && lastErrStr == "":
 							return ""
-						} else if err != nil {
+						case err != nil:
 							return errors.Wrapf(err, lastErrStr).Error()
+						default:
+							return lastErrStr
 						}
-						return lastErrStr
 					}(),
 					LastScrape:         target.LastScrape(),
 					LastScrapeDuration: target.LastScrapeDuration().Seconds(),
--- a/web/federate_test.go
+++ b/web/federate_test.go
@ -388,13 +388,13 @@ func TestFederationWithNativeHistograms(t *testing.T) {
 			break
 		}
 		require.NoError(t, err)
-		if et == textparse.EntryHelp {
-			metricFamilies++
-		}
 		if et == textparse.EntryHistogram || et == textparse.EntrySeries {
 			p.Metric(&l)
 		}
-		if et == textparse.EntryHistogram {
+		switch et {
+		case textparse.EntryHelp:
+			metricFamilies++
+		case textparse.EntryHistogram:
 			_, parsedTimestamp, h, fh := p.Histogram()
 			require.Nil(t, h)
 			actVec = append(actVec, promql.Sample{
@ -402,7 +402,7 @@ func TestFederationWithNativeHistograms(t *testing.T) {
 				H:      fh,
 				Metric: l,
 			})
-		} else if et == textparse.EntrySeries {
+		case textparse.EntrySeries:
 			_, parsedTimestamp, f := p.Series()
 			actVec = append(actVec, promql.Sample{
 				T:      *parsedTimestamp,