chore: enable gocritic linter (#7095)

#### Description

Enable and fixes several rules from
[gocritic](https://golangci-lint.run/usage/linters/#gocritic) linter

---------

Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

.golangci.yml

@@ -10,6 +10,7 @@ linters:
     - depguard
     - errcheck
     - errorlint
+    - gocritic
     - godot
     - gosec
     - govet
@@ -86,6 +87,20 @@ linters:
           deny:
             - pkg: go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal
               desc: Do not use cross-module internal packages.
+    gocritic:
+      disabled-checks:
+        - appendAssign
+        - commentedOutCode
+        - dupArg
+        - hugeParam
+        - importShadow
+        - paramTypeCombine
+        - ptrToRefParam
+        - preferDecodeRune
+        - rangeValCopy
+        - unnamedResult
+        - whyNoLint
+      enable-all: true
     godot:
       exclude:
         # Exclude links.
@@ -225,10 +240,6 @@ linters:
       - linters:
           - gosec
         text: 'G402: TLS MinVersion too low.'
-    paths:
-      - third_party$
-      - builtin$
-      - examples$
 issues:
   max-issues-per-linter: 0
   max-same-issues: 0
@@ -245,7 +256,3 @@ formatters:
       max-len: 120
   exclusions:
     generated: lax
-    paths:
-      - third_party$
-      - builtin$
-      - examples$

attribute/encoder.go

@@ -96,11 +96,11 @@ func (d *defaultAttrEncoder) Encode(iter Iterator) string {
 	for iter.Next() {
 		i, keyValue := iter.IndexedAttribute()
 		if i > 0 {
-			_, _ = buf.WriteRune(',')
+			_ = buf.WriteByte(',')
 		}
 		copyAndEscape(buf, string(keyValue.Key))
 
-		_, _ = buf.WriteRune('=')
+		_ = buf.WriteByte('=')
 
 		if keyValue.Value.Type() == STRING {
 			copyAndEscape(buf, keyValue.Value.AsString())
@@ -122,7 +122,7 @@ func copyAndEscape(buf *bytes.Buffer, val string) {
 	for _, ch := range val {
 		switch ch {
 		case '=', ',', escapeChar:
-			_, _ = buf.WriteRune(escapeChar)
+			_ = buf.WriteByte(escapeChar)
 		}
 		_, _ = buf.WriteRune(ch)
 	}

attribute/filter.go

@@ -15,7 +15,7 @@ type Filter func(KeyValue) bool
 //
 // If keys is empty a deny-all filter is returned.
 func NewAllowKeysFilter(keys ...Key) Filter {
-	if len(keys) <= 0 {
+	if len(keys) == 0 {
 		return func(kv KeyValue) bool { return false }
 	}
 
@@ -34,7 +34,7 @@ func NewAllowKeysFilter(keys ...Key) Filter {
 //
 // If keys is empty an allow-all filter is returned.
 func NewDenyKeysFilter(keys ...Key) Filter {
-	if len(keys) <= 0 {
+	if len(keys) == 0 {
 		return func(kv KeyValue) bool { return true }
 	}
 

baggage/baggage.go

@@ -812,7 +812,7 @@ var safeKeyCharset = [utf8.RuneSelf]bool{
 // validateBaggageName checks if the string is a valid OpenTelemetry Baggage name.
 // Baggage name is a valid, non-empty UTF-8 string.
 func validateBaggageName(s string) bool {
-	if len(s) == 0 {
+	if s == "" {
 		return false
 	}
 
@@ -828,7 +828,7 @@ func validateBaggageValue(s string) bool {
 
 // validateKey checks if the string is a valid W3C Baggage key.
 func validateKey(s string) bool {
-	if len(s) == 0 {
+	if s == "" {
 		return false
 	}
 

bridge/opencensus/trace_test.go

@@ -134,12 +134,10 @@ func TestOTelSpanContextToOC(t *testing.T) {
 					gotTraceState = strings.Join(gotTraceStateEntries, ",")
 				}
 				assert.Equal(t, expectedTraceState, gotTraceState, "Tracestate should preserve entries")
-			} else {
+			} else if got.Tracestate != nil {
 				// For empty tracestate cases, ensure the field is properly handled
-				if got.Tracestate != nil {
+				entries := got.Tracestate.Entries()
-					entries := got.Tracestate.Entries()
+				assert.Empty(t, entries, "Empty tracestate should result in empty entries")
-					assert.Empty(t, entries, "Empty tracestate should result in empty entries")
-				}
 			}
 		})
 	}

bridge/opentracing/bridge_test.go

@@ -135,7 +135,7 @@ var (
 type testTextMapPropagator struct{}
 
 func (t testTextMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
-	carrier.Set(testHeader, strings.Join([]string{traceID.String(), spanID.String()}, ":"))
+	carrier.Set(testHeader, traceID.String()+":"+spanID.String())
 
 	// Test for panic
 	_ = carrier.Get("test")

exporters/otlp/otlplog/otlploggrpc/client.go

@@ -86,11 +86,12 @@ func newGRPCDialOptions(cfg config) []grpc.DialOption {
 		dialOpts = append(dialOpts, grpc.WithDefaultServiceConfig(cfg.serviceConfig.Value))
 	}
 	// Prioritize GRPCCredentials over Insecure (passing both is an error).
-	if cfg.gRPCCredentials.Value != nil {
+	switch {
+	case cfg.gRPCCredentials.Value != nil:
 		dialOpts = append(dialOpts, grpc.WithTransportCredentials(cfg.gRPCCredentials.Value))
-	} else if cfg.insecure.Value {
+	case cfg.insecure.Value:
 		dialOpts = append(dialOpts, grpc.WithTransportCredentials(insecure.NewCredentials()))
-	} else {
+	default:
 		// Default to using the host's root CA.
 		dialOpts = append(dialOpts, grpc.WithTransportCredentials(
 			credentials.NewTLS(nil),

exporters/otlp/otlplog/otlploggrpc/config.go

@@ -563,7 +563,7 @@ func loadCertificates(certPath, keyPath string) ([]tls.Certificate, error) {
 func insecureFromScheme(prev setting[bool], scheme string) setting[bool] {
 	if scheme == "https" {
 		return newSetting(false)
-	} else if len(scheme) > 0 {
+	} else if scheme != "" {
 		return newSetting(true)
 	}
 

exporters/otlp/otlplog/otlploggrpc/config_test.go

@@ -525,10 +525,8 @@ func assertTLSConfig(t *testing.T, want, got setting[*tls.Config]) {
 
 	if want.Value.RootCAs == nil {
 		assert.Nil(t, got.Value.RootCAs, "*tls.Config.RootCAs")
-	} else {
+	} else if assert.NotNil(t, got.Value.RootCAs, "RootCAs") {
-		if assert.NotNil(t, got.Value.RootCAs, "RootCAs") {
+		assert.True(t, want.Value.RootCAs.Equal(got.Value.RootCAs), "RootCAs equal")
-			assert.True(t, want.Value.RootCAs.Equal(got.Value.RootCAs), "RootCAs equal")
-		}
 	}
 	assert.Equal(t, want.Value.Certificates, got.Value.Certificates, "Certificates")
 }

exporters/otlp/otlplog/otlploghttp/client.go

@@ -200,7 +200,7 @@ func (c *httpClient) uploadLogs(ctx context.Context, data []*logpb.ResourceLogs)
 			return err
 		}
 		respStr := strings.TrimSpace(respData.String())
-		if len(respStr) == 0 {
+		if respStr == "" {
 			respStr = "(empty)"
 		}
 		bodyErr := fmt.Errorf("body: %s", respStr)
@@ -232,7 +232,7 @@ func (c *httpClient) newRequest(ctx context.Context, body []byte) (request, erro
 
 	switch c.compression {
 	case NoCompression:
-		r.ContentLength = (int64)(len(body))
+		r.ContentLength = int64(len(body))
 		req.bodyReader = bodyReader(body)
 	case GzipCompression:
 		// Ensure the content length is not used.

exporters/otlp/otlplog/otlploghttp/config_test.go

@@ -460,10 +460,8 @@ func assertTLSConfig(t *testing.T, want, got setting[*tls.Config]) {
 
 	if want.Value.RootCAs == nil {
 		assert.Nil(t, got.Value.RootCAs, "*tls.Config.RootCAs")
-	} else {
+	} else if assert.NotNil(t, got.Value.RootCAs, "RootCAs") {
-		if assert.NotNil(t, got.Value.RootCAs, "RootCAs") {
+		assert.True(t, want.Value.RootCAs.Equal(got.Value.RootCAs), "RootCAs equal")
-			assert.True(t, want.Value.RootCAs.Equal(got.Value.RootCAs), "RootCAs equal")
-		}
 	}
 	assert.Equal(t, want.Value.Certificates, got.Value.Certificates, "Certificates")
 }

exporters/otlp/otlpmetric/otlpmetrichttp/client.go

@@ -203,7 +203,7 @@ func (c *client) UploadMetrics(ctx context.Context, protoMetrics *metricpb.Resou
 			return err
 		}
 		respStr := strings.TrimSpace(respData.String())
-		if len(respStr) == 0 {
+		if respStr == "" {
 			respStr = "(empty)"
 		}
 		bodyErr := fmt.Errorf("body: %s", respStr)
@@ -235,7 +235,7 @@ func (c *client) newRequest(ctx context.Context, body []byte) (request, error) {
 
 	switch c.compression {
 	case NoCompression:
-		r.ContentLength = (int64)(len(body))
+		r.ContentLength = int64(len(body))
 		req.bodyReader = bodyReader(body)
 	case GzipCompression:
 		// Ensure the content length is not used.

exporters/otlp/otlptrace/otlptracehttp/client.go

@@ -209,7 +209,7 @@ func (d *client) UploadTraces(ctx context.Context, protoSpans []*tracepb.Resourc
 			return err
 		}
 		respStr := strings.TrimSpace(respData.String())
-		if len(respStr) == 0 {
+		if respStr == "" {
 			respStr = "(empty)"
 		}
 		bodyErr := fmt.Errorf("body: %s", respStr)
@@ -230,7 +230,7 @@ func (d *client) UploadTraces(ctx context.Context, protoSpans []*tracepb.Resourc
 
 func (d *client) newRequest(body []byte) (request, error) {
 	u := url.URL{Scheme: d.getScheme(), Host: d.cfg.Endpoint, Path: d.cfg.URLPath}
-	r, err := http.NewRequest(http.MethodPost, u.String(), nil)
+	r, err := http.NewRequest(http.MethodPost, u.String(), http.NoBody)
 	if err != nil {
 		return request{Request: r}, err
 	}
@@ -246,7 +246,7 @@ func (d *client) newRequest(body []byte) (request, error) {
 	req := request{Request: r}
 	switch Compression(d.cfg.Compression) {
 	case NoCompression:
-		r.ContentLength = (int64)(len(body))
+		r.ContentLength = int64(len(body))
 		req.bodyReader = bodyReader(body)
 	case GzipCompression:
 		// Ensure the content length is not used.

exporters/prometheus/exporter.go

@@ -640,8 +640,8 @@ func addExemplars[N int64 | float64](
 	for i, exemplar := range exemplars {
 		labels := attributesToLabels(exemplar.FilteredAttributes, labelNamer)
 		// Overwrite any existing trace ID or span ID attributes
-		labels[otlptranslator.ExemplarTraceIDKey] = hex.EncodeToString(exemplar.TraceID[:])
+		labels[otlptranslator.ExemplarTraceIDKey] = hex.EncodeToString(exemplar.TraceID)
-		labels[otlptranslator.ExemplarSpanIDKey] = hex.EncodeToString(exemplar.SpanID[:])
+		labels[otlptranslator.ExemplarSpanIDKey] = hex.EncodeToString(exemplar.SpanID)
 		promExemplars[i] = prometheus.Exemplar{
 			Value:     float64(exemplar.Value),
 			Timestamp: exemplar.Time,

exporters/zipkin/model.go

@@ -150,11 +150,11 @@ func toZipkinAnnotations(events []tracesdk.Event) []zkmodel.Annotation {
 func attributesToJSONMapString(attributes []attribute.KeyValue) string {
 	m := make(map[string]any, len(attributes))
 	for _, a := range attributes {
-		m[(string)(a.Key)] = a.Value.AsInterface()
+		m[string(a.Key)] = a.Value.AsInterface()
 	}
 	// if an error happens, the result will be an empty string
 	jsonBytes, _ := json.Marshal(m)
-	return (string)(jsonBytes)
+	return string(jsonBytes)
 }
 
 // attributeToStringPair serializes each attribute to a string pair.
@@ -163,18 +163,18 @@ func attributeToStringPair(kv attribute.KeyValue) (string, string) {
 	// For slice attributes, serialize as JSON list string.
 	case attribute.BOOLSLICE:
 		data, _ := json.Marshal(kv.Value.AsBoolSlice())
-		return (string)(kv.Key), (string)(data)
+		return string(kv.Key), string(data)
 	case attribute.INT64SLICE:
 		data, _ := json.Marshal(kv.Value.AsInt64Slice())
-		return (string)(kv.Key), (string)(data)
+		return string(kv.Key), string(data)
 	case attribute.FLOAT64SLICE:
 		data, _ := json.Marshal(kv.Value.AsFloat64Slice())
-		return (string)(kv.Key), (string)(data)
+		return string(kv.Key), string(data)
 	case attribute.STRINGSLICE:
 		data, _ := json.Marshal(kv.Value.AsStringSlice())
-		return (string)(kv.Key), (string)(data)
+		return string(kv.Key), string(data)
 	default:
-		return (string)(kv.Key), kv.Value.Emit()
+		return string(kv.Key), kv.Value.Emit()
 	}
 }
 

exporters/zipkin/zipkin.go

@@ -146,7 +146,7 @@ func (e *Exporter) ExportSpans(ctx context.Context, spans []sdktrace.ReadOnlySpa
 	req.Header.Set("Content-Type", "application/json")
 
 	for k, v := range e.headers {
-		if strings.ToLower(k) == "host" {
+		if strings.EqualFold(k, "host") {
 			req.Host = v
 		} else {
 			req.Header.Set(k, v)

exporters/zipkin/zipkin_test.go

@@ -171,7 +171,7 @@ type logStore struct {
 }
 
 func (s *logStore) Write(p []byte) (n int, err error) {
-	msg := (string)(p)
+	msg := string(p)
 	if s.T != nil {
 		s.T.Logf("%s", msg)
 	}

internal/global/internal_logging_test.go

@@ -91,7 +91,7 @@ func TestLogLevel(t *testing.T) {
 
 func newBuffLogger(buf *bytes.Buffer, verbosity int) logr.Logger {
 	return funcr.New(func(prefix, args string) {
-		_, _ = buf.Write([]byte(args))
+		_, _ = buf.WriteString(args)
 	}, funcr.Options{
 		Verbosity: verbosity,
 	})

propagation/baggage_test.go

@@ -124,7 +124,7 @@ func TestExtractValidBaggage(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			mapCarr := propagation.MapCarrier{}
 			mapCarr["baggage"] = tt.header
-			req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+			req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 			req.Header.Set("baggage", tt.header)
 
 			// test with http header carrier (which implements ValuesGetter)
@@ -183,7 +183,7 @@ func TestExtractValidMultipleBaggageHeaders(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+			req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 			req.Header["Baggage"] = tt.headers
 
 			ctx := context.Background()
@@ -239,7 +239,7 @@ func TestExtractInvalidDistributedContextFromHTTPReq(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+			req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 			req.Header.Set("baggage", tt.header)
 
 			expected := tt.has.Baggage(t)
@@ -292,7 +292,7 @@ func TestInjectBaggageToHTTPReq(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+			req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 			ctx := baggage.ContextWithBaggage(context.Background(), tt.mems.Baggage(t))
 			propagator.Inject(ctx, propagation.HeaderCarrier(req.Header))
 
@@ -339,7 +339,7 @@ func TestBaggageInjectExtractRoundtrip(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			b := tt.mems.Baggage(t)
-			req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+			req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 			ctx := baggage.ContextWithBaggage(context.Background(), b)
 			propagator.Inject(ctx, propagation.HeaderCarrier(req.Header))
 

propagation/trace_context_benchmark_test.go

@@ -56,7 +56,7 @@ func BenchmarkExtract(b *testing.B) {
 
 func extractSubBenchmarks(b *testing.B, fn func(*testing.B, *http.Request)) {
 	b.Run("Sampled", func(b *testing.B) {
-		req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+		req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 		req.Header.Set("traceparent", "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01")
 		b.ReportAllocs()
 
@@ -64,14 +64,14 @@ func extractSubBenchmarks(b *testing.B, fn func(*testing.B, *http.Request)) {
 	})
 
 	b.Run("BogusVersion", func(b *testing.B) {
-		req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+		req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 		req.Header.Set("traceparent", "qw-00000000000000000000000000000000-0000000000000000-01")
 		b.ReportAllocs()
 		fn(b, req)
 	})
 
 	b.Run("FutureAdditionalData", func(b *testing.B) {
-		req, _ := http.NewRequest(http.MethodGet, "http://example.com", nil)
+		req, _ := http.NewRequest(http.MethodGet, "http://example.com", http.NoBody)
 		req.Header.Set("traceparent", "02-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-09-XYZxsf09")
 		b.ReportAllocs()
 		fn(b, req)

sdk/internal/x/x.go

@@ -19,7 +19,7 @@ import (
 // to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
 // will also enable this).
 var Resource = newFeature("RESOURCE", func(v string) (string, bool) {
-	if strings.ToLower(v) == "true" {
+	if strings.EqualFold(v, "true") {
 		return v, true
 	}
 	return "", false

sdk/log/ring_test.go

@@ -15,9 +15,9 @@ import (
 	"go.opentelemetry.io/otel/log"
 )
 
-func verifyRing(t *testing.T, r *ring, N int, sum int) {
+func verifyRing(t *testing.T, r *ring, num int, sum int) {
 	// Length.
-	assert.Equal(t, N, r.Len(), "r.Len()")
+	assert.Equal(t, num, r.Len(), "r.Len()")
 
 	// Iteration.
 	var n, s int
@@ -28,7 +28,7 @@ func verifyRing(t *testing.T, r *ring, N int, sum int) {
 			s += int(body.AsInt64())
 		}
 	})
-	assert.Equal(t, N, n, "number of forward iterations")
+	assert.Equal(t, num, n, "number of forward iterations")
 	if sum >= 0 {
 		assert.Equal(t, sum, s, "forward ring sum")
 	}

sdk/metric/exemplar/fixed_size_reservoir.go

@@ -125,13 +125,11 @@ func (r *FixedSizeReservoir) Offer(ctx context.Context, t time.Time, n Value, a
 
 	if int(r.count) < cap(r.store) {
 		r.store[r.count] = newMeasurement(ctx, t, n, a)
-	} else {
+	} else if r.count == r.next {
-		if r.count == r.next {
+		// Overwrite a random existing measurement with the one offered.
-			// Overwrite a random existing measurement with the one offered.
+		idx := int(rand.Int64N(int64(cap(r.store))))
-			idx := int(rand.Int64N(int64(cap(r.store))))
+		r.store[idx] = newMeasurement(ctx, t, n, a)
-			r.store[idx] = newMeasurement(ctx, t, n, a)
+		r.advance()
-			r.advance()
-		}
 	}
 	r.count++
 }

sdk/metric/internal/aggregate/exponential_histogram.go

@@ -183,8 +183,8 @@ func (p *expoHistogramDataPoint[N]) scaleChange(bin, startBin int32, length int)
 
 	var count int32
 	for high-low >= p.maxSize {
-		low = low >> 1
+		low >>= 1
-		high = high >> 1
+		high >>= 1
 		count++
 		if count > expoMaxScale-expoMinScale {
 			return count
@@ -225,7 +225,7 @@ func (b *expoBuckets) record(bin int32) {
 			b.counts = append(b.counts, make([]uint64, newLength-len(b.counts))...)
 		}
 
-		copy(b.counts[shift:origLen+int(shift)], b.counts[:])
+		copy(b.counts[shift:origLen+int(shift)], b.counts)
 		b.counts = b.counts[:newLength]
 		for i := 1; i < int(shift); i++ {
 			b.counts[i] = 0
@@ -264,7 +264,7 @@ func (b *expoBuckets) downscale(delta int32) {
 	// new Counts: [4, 14, 30, 10]
 
 	if len(b.counts) <= 1 || delta < 1 {
-		b.startBin = b.startBin >> delta
+		b.startBin >>= delta
 		return
 	}
 
@@ -282,7 +282,7 @@ func (b *expoBuckets) downscale(delta int32) {
 
 	lastIdx := (len(b.counts) - 1 + int(offset)) / int(steps)
 	b.counts = b.counts[:lastIdx+1]
-	b.startBin = b.startBin >> delta
+	b.startBin >>= delta
 }
 
 // newExponentialHistogram returns an Aggregator that summarizes a set of

sdk/metric/internal/aggregate/exponential_histogram_test.go

@@ -656,7 +656,7 @@ func BenchmarkPrepend(b *testing.B) {
 		n := math.MaxFloat64
 		for range 1024 {
 			agg.record(n)
-			n = n / 2
+			n /= 2
 		}
 	}
 }
@@ -667,7 +667,7 @@ func BenchmarkAppend(b *testing.B) {
 		n := smallestNonZeroNormalFloat64
 		for range 1024 {
 			agg.record(n)
-			n = n * 2
+			n *= 2
 		}
 	}
 }
@@ -1061,7 +1061,7 @@ func FuzzGetBin(f *testing.F) {
 	f.Fuzz(func(t *testing.T, v float64, scale int32) {
 		// GetBin only works on positive values.
 		if math.Signbit(v) {
-			v = v * -1
+			v *= -1
 		}
 		// GetBin Doesn't work on zero.
 		if v == 0.0 {

sdk/metric/meter.go

@@ -423,7 +423,7 @@ func (m *meter) Float64ObservableGauge(
 }
 
 func validateInstrumentName(name string) error {
-	if len(name) == 0 {
+	if name == "" {
 		return fmt.Errorf("%w: %s: is empty", ErrInstrumentName, name)
 	}
 	if len(name) > 255 {

sdk/metric/pipeline_test.go

@@ -653,32 +653,31 @@ func TestPipelineProduceErrors(t *testing.T) {
 	var shouldReturnError bool   // When true, the third callback returns an error
 	var callbackCounts [3]int
 
-	// Callback 1: cancels the context during execution but continues to populate data
+	pipe.callbacks = append(pipe.callbacks,
-	pipe.callbacks = append(pipe.callbacks, func(ctx context.Context) error {
+		// Callback 1: cancels the context during execution but continues to populate data
-		callbackCounts[0]++
+		func(ctx context.Context) error {
-		for _, m := range pipe.int64Measures[testObsID] {
+			callbackCounts[0]++
-			m(ctx, 123, *attribute.EmptySet())
+			for _, m := range pipe.int64Measures[testObsID] {
-		}
+				m(ctx, 123, *attribute.EmptySet())
-		return nil
+			}
-	})
+			return nil
-
+		},
-	// Callback 2: populates int64 observable data
+		// Callback 2: populates int64 observable data
-	pipe.callbacks = append(pipe.callbacks, func(ctx context.Context) error {
+		func(ctx context.Context) error {
-		callbackCounts[1]++
+			callbackCounts[1]++
-		if shouldCancelContext {
+			if shouldCancelContext {
-			cancelCtx()
+				cancelCtx()
-		}
+			}
-		return nil
+			return nil
-	})
+		},
-
+		// Callback 3: return an error
-	// Callback 3: return an error
+		func(ctx context.Context) error {
-	pipe.callbacks = append(pipe.callbacks, func(ctx context.Context) error {
+			callbackCounts[2]++
-		callbackCounts[2]++
+			if shouldReturnError {
-		if shouldReturnError {
+				return fmt.Errorf("test callback error")
-			return fmt.Errorf("test callback error")
+			}
-		}
+			return nil
-		return nil
+		})
-	})
 
 	assertMetrics := func(rm *metricdata.ResourceMetrics, expectVal int64) {
 		require.Len(t, rm.ScopeMetrics, 1)

sdk/resource/os_release_unix.go

@@ -68,7 +68,7 @@ func parseOSReleaseFile(file io.Reader) map[string]string {
 func skip(line string) bool {
 	line = strings.TrimSpace(line)
 
-	return len(line) == 0 || strings.HasPrefix(line, "#")
+	return line == "" || strings.HasPrefix(line, "#")
 }
 
 // parse attempts to split the provided line on the first '=' character, and then
@@ -76,7 +76,7 @@ func skip(line string) bool {
 func parse(line string) (string, string, bool) {
 	k, v, found := strings.Cut(line, "=")
 
-	if !found || len(k) == 0 {
+	if !found || k == "" {
 		return "", "", false
 	}
 

sdk/trace/batch_span_processor_test.go

@@ -505,7 +505,7 @@ func TestBatchSpanProcessorDropBatchIfFailed(t *testing.T) {
 func assertMaxSpanDiff(t *testing.T, want, got, maxDif int) {
 	spanDifference := want - got
 	if spanDifference < 0 {
-		spanDifference = spanDifference * -1
+		spanDifference *= -1
 	}
 	if spanDifference > maxDif {
 		t.Errorf("number of exported span not equal to or within %d less than: got %+v, want %+v\n",
@@ -514,7 +514,7 @@ func assertMaxSpanDiff(t *testing.T, want, got, maxDif int) {
 }
 
 type indefiniteExporter struct {
-	stop chan (struct{})
+	stop chan struct{}
 }
 
 func newIndefiniteExporter(t *testing.T) indefiniteExporter {

sdk/trace/internal/x/x.go

@@ -16,7 +16,7 @@ import (
 // to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
 // will also enable this).
 var SelfObservability = newFeature("SELF_OBSERVABILITY", func(v string) (string, bool) {
-	if strings.ToLower(v) == "true" {
+	if strings.EqualFold(v, "true") {
 		return v, true
 	}
 	return "", false

sdk/trace/tracer.go

@@ -92,13 +92,14 @@ func (tr *tracer) Start(
 
 		// Determine the sampling result and create the corresponding attribute.
 		var attrSamplingResult attribute.KeyValue
-		if s.SpanContext().IsSampled() && s.IsRecording() {
+		switch {
+		case s.SpanContext().IsSampled() && s.IsRecording():
 			attrSamplingResult = tr.spanStartedMetric.AttrSpanSamplingResult(
 				otelconv.SpanSamplingResultRecordAndSample,
 			)
-		} else if s.IsRecording() {
+		case s.IsRecording():
 			attrSamplingResult = tr.spanStartedMetric.AttrSpanSamplingResult(otelconv.SpanSamplingResultRecordOnly)
-		} else {
+		default:
 			attrSamplingResult = tr.spanStartedMetric.AttrSpanSamplingResult(otelconv.SpanSamplingResultDrop)
 		}
 

semconv/internal/http_test.go

@@ -1008,7 +1008,7 @@ func kvStr(kvs []attribute.KeyValue) string {
 		if idx > 0 {
 			_, _ = sb.WriteString(", ")
 		}
-		_, _ = sb.WriteString((string)(attr.Key))
+		_, _ = sb.WriteString(string(attr.Key))
 		_, _ = sb.WriteString(": ")
 		_, _ = sb.WriteString(attr.Value.Emit())
 	}

semconv/internal/v2/http.go

@@ -91,8 +91,7 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(attrs, c.method(req.Method), c.proto(req.Proto))
-	attrs = append(attrs, c.proto(req.Proto))
 
 	var u string
 	if req.URL != nil {
@@ -103,9 +102,11 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 		// Restore any username/password info that was removed.
 		req.URL.User = userinfo
 	}
-	attrs = append(attrs, c.HTTPURLKey.String(u))
+	attrs = append(
-
+		attrs,
-	attrs = append(attrs, c.NetConv.PeerName(peer))
+		c.HTTPURLKey.String(u),
+		c.NetConv.PeerName(peer),
+	)
 	if port > 0 {
 		attrs = append(attrs, c.NetConv.PeerPort(port))
 	}
@@ -191,10 +192,13 @@ func (c *HTTPConv) ServerRequest(server string, req *http.Request) []attribute.K
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(
-	attrs = append(attrs, c.scheme(req.TLS != nil))
+		attrs,
-	attrs = append(attrs, c.proto(req.Proto))
+		c.method(req.Method),
-	attrs = append(attrs, c.NetConv.HostName(host))
+		c.scheme(req.TLS != nil),
+		c.proto(req.Proto),
+		c.NetConv.HostName(host),
+	)
 
 	if hostPort > 0 {
 		attrs = append(attrs, c.NetConv.HostPort(hostPort))

semconv/internal/v3/http.go

@@ -91,8 +91,7 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(attrs, c.method(req.Method), c.proto(req.Proto))
-	attrs = append(attrs, c.proto(req.Proto))
 
 	var u string
 	if req.URL != nil {
@@ -103,9 +102,11 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 		// Restore any username/password info that was removed.
 		req.URL.User = userinfo
 	}
-	attrs = append(attrs, c.HTTPURLKey.String(u))
+	attrs = append(
-
+		attrs,
-	attrs = append(attrs, c.NetConv.PeerName(peer))
+		c.HTTPURLKey.String(u),
+		c.NetConv.PeerName(peer),
+	)
 	if port > 0 {
 		attrs = append(attrs, c.NetConv.PeerPort(port))
 	}
@@ -191,10 +192,13 @@ func (c *HTTPConv) ServerRequest(server string, req *http.Request) []attribute.K
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(
-	attrs = append(attrs, c.scheme(req.TLS != nil))
+		attrs,
-	attrs = append(attrs, c.proto(req.Proto))
+		c.method(req.Method),
-	attrs = append(attrs, c.NetConv.HostName(host))
+		c.scheme(req.TLS != nil),
+		c.proto(req.Proto),
+		c.NetConv.HostName(host),
+	)
 
 	if hostPort > 0 {
 		attrs = append(attrs, c.NetConv.HostPort(hostPort))

semconv/internal/v4/http.go

@@ -92,8 +92,7 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(attrs, c.method(req.Method), c.proto(req.Proto))
-	attrs = append(attrs, c.proto(req.Proto))
 
 	var u string
 	if req.URL != nil {
@@ -104,9 +103,11 @@ func (c *HTTPConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 		// Restore any username/password info that was removed.
 		req.URL.User = userinfo
 	}
-	attrs = append(attrs, c.HTTPURLKey.String(u))
+	attrs = append(
-
+		attrs,
-	attrs = append(attrs, c.NetConv.PeerName(peer))
+		c.HTTPURLKey.String(u),
+		c.NetConv.PeerName(peer),
+	)
 	if port > 0 {
 		attrs = append(attrs, c.NetConv.PeerPort(port))
 	}
@@ -192,10 +193,13 @@ func (c *HTTPConv) ServerRequest(server string, req *http.Request) []attribute.K
 	}
 	attrs := make([]attribute.KeyValue, 0, n)
 
-	attrs = append(attrs, c.method(req.Method))
+	attrs = append(
-	attrs = append(attrs, c.scheme(req.TLS != nil))
+		attrs,
-	attrs = append(attrs, c.proto(req.Proto))
+		c.method(req.Method),
-	attrs = append(attrs, c.NetConv.HostName(host))
+		c.scheme(req.TLS != nil),
+		c.proto(req.Proto),
+		c.NetConv.HostName(host),
+	)
 
 	if hostPort > 0 {
 		attrs = append(attrs, c.NetConv.HostPort(hostPort))

trace/trace.go

@@ -165,7 +165,7 @@ func (tf TraceFlags) MarshalJSON() ([]byte, error) {
 
 // String returns the hex string representation form of TraceFlags.
 func (tf TraceFlags) String() string {
-	return hex.EncodeToString([]byte{byte(tf)}[:])
+	return hex.EncodeToString([]byte{byte(tf)})
 }
 
 // SpanContextConfig contains mutable fields usable for constructing

trace/tracestate.go

@@ -80,7 +80,7 @@ func checkKeyRemain(key string) bool {
 //
 // param n is remain part length, should be 255 in simple-key or 13 in system-id.
 func checkKeyPart(key string, n int) bool {
-	if len(key) == 0 {
+	if key == "" {
 		return false
 	}
 	first := key[0] // key's first char
@@ -102,7 +102,7 @@ func isAlphaNum(c byte) bool {
 //
 // param n is remain part length, should be 240 exactly.
 func checkKeyTenant(key string, n int) bool {
-	if len(key) == 0 {
+	if key == "" {
 		return false
 	}
 	return isAlphaNum(key[0]) && len(key[1:]) <= n && checkKeyRemain(key[1:])
@@ -191,7 +191,7 @@ func ParseTraceState(ts string) (TraceState, error) {
 	for ts != "" {
 		var memberStr string
 		memberStr, ts, _ = strings.Cut(ts, listDelimiters)
-		if len(memberStr) == 0 {
+		if memberStr == "" {
 			continue
 		}