Use gofumpt instead of gofmt (#4623)

* Use gofumpt instead of gofmt in golangci-lint conf

* Run gofumpt fixes

* Format generated templates

---------

Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>

.golangci.yml

@@ -12,7 +12,7 @@ linters:
     - depguard
     - errcheck
     - godot
-    - gofmt
+    - gofumpt
     - goimports
     - gosimple
     - govet

attribute/key_test.go

@@ -41,7 +41,7 @@ func TestDefined(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//func (k attribute.Key) Defined() bool {
+			// func (k attribute.Key) Defined() bool {
 			have := testcase.k.Defined()
 			if have != testcase.want {
 				t.Errorf("Want: %v, but have: %v", testcase.want, have)
@@ -91,7 +91,7 @@ func TestEmit(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//proto: func (v attribute.Value) Emit() string {
+			// proto: func (v attribute.Value) Emit() string {
 			have := testcase.v.Emit()
 			if have != testcase.want {
 				t.Errorf("Want: %s, but have: %s", testcase.want, have)

bridge/opencensus/internal/ocmetric/metric_test.go

@@ -56,7 +56,6 @@ func TestConvertMetrics(t *testing.T) {
 					},
 					TimeSeries: []*ocmetricdata.TimeSeries{
 						{
-
 							LabelValues: []ocmetricdata.LabelValue{
 								{
 									Value:   "hello",
@@ -370,7 +369,8 @@ func TestConvertMetrics(t *testing.T) {
 					},
 				},
 			},
-		}, {
+		},
+		{
 			desc: "histogram without data points",
 			input: []*ocmetricdata.Metric{
 				{
@@ -393,7 +393,8 @@ func TestConvertMetrics(t *testing.T) {
 					},
 				},
 			},
-		}, {
+		},
+		{
 			desc: "sum without data points",
 			input: []*ocmetricdata.Metric{
 				{
@@ -417,7 +418,8 @@ func TestConvertMetrics(t *testing.T) {
 					},
 				},
 			},
-		}, {
+		},
+		{
 			desc: "gauge without data points",
 			input: []*ocmetricdata.Metric{
 				{
@@ -439,7 +441,8 @@ func TestConvertMetrics(t *testing.T) {
 					},
 				},
 			},
-		}, {
+		},
+		{
 			desc: "histogram with negative count",
 			input: []*ocmetricdata.Metric{
 				{
@@ -462,7 +465,8 @@ func TestConvertMetrics(t *testing.T) {
 				},
 			},
 			expectedErr: errNegativeDistributionCount,
-		}, {
+		},
+		{
 			desc: "histogram with negative bucket count",
 			input: []*ocmetricdata.Metric{
 				{
@@ -489,7 +493,8 @@ func TestConvertMetrics(t *testing.T) {
 				},
 			},
 			expectedErr: errNegativeBucketCount,
-		}, {
+		},
+		{
 			desc: "histogram with non-histogram datapoint type",
 			input: []*ocmetricdata.Metric{
 				{
@@ -510,7 +515,8 @@ func TestConvertMetrics(t *testing.T) {
 				},
 			},
 			expectedErr: errMismatchedValueTypes,
-		}, {
+		},
+		{
 			desc: "sum with non-sum datapoint type",
 			input: []*ocmetricdata.Metric{
 				{
@@ -531,7 +537,8 @@ func TestConvertMetrics(t *testing.T) {
 				},
 			},
 			expectedErr: errMismatchedValueTypes,
-		}, {
+		},
+		{
 			desc: "gauge with non-gauge datapoint type",
 			input: []*ocmetricdata.Metric{
 				{
@@ -552,7 +559,8 @@ func TestConvertMetrics(t *testing.T) {
 				},
 			},
 			expectedErr: errMismatchedValueTypes,
-		}, {
+		},
+		{
 			desc: "unsupported Gauge Distribution type",
 			input: []*ocmetricdata.Metric{
 				{

bridge/opentracing/bridge.go

@@ -317,8 +317,10 @@ type BridgeTracer struct {
 	propagator propagation.TextMapPropagator
 }
 
-var _ ot.Tracer = &BridgeTracer{}
-var _ ot.TracerContextWithSpanExtension = &BridgeTracer{}
+var (
+	_ ot.Tracer                         = &BridgeTracer{}
+	_ ot.TracerContextWithSpanExtension = &BridgeTracer{}
+)
 
 // NewBridgeTracer creates a new BridgeTracer. The new tracer forwards
 // the calls to the OpenTelemetry Noop tracer, so it should be
@@ -829,15 +831,13 @@ func newTextMapWrapperForInject(carrier interface{}) (*textMapWrapper, error) {
 	return t, nil
 }
 
-type textMapWriter struct {
-}
+type textMapWriter struct{}
 
 func (t *textMapWriter) Set(key string, value string) {
 	// maybe print a warning log.
 }
 
-type textMapReader struct {
-}
+type textMapReader struct{}
 
 func (t *textMapReader) ForeachKey(handler func(key, val string) error) error {
 	return nil // maybe print a warning log.

bridge/opentracing/bridge_test.go

@@ -35,8 +35,7 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-type testOnlyTextMapReader struct {
-}
+type testOnlyTextMapReader struct{}
 
 func newTestOnlyTextMapReader() *testOnlyTextMapReader {
 	return &testOnlyTextMapReader{}
@@ -144,8 +143,7 @@ var (
 	spanID     trace.SpanID  = [8]byte{byte(11)}
 )
 
-type testTextMapPropagator struct {
-}
+type testTextMapPropagator struct{}
 
 func (t testTextMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
 	carrier.Set(testHeader, strings.Join([]string{traceID.String(), spanID.String()}, ":"))
@@ -163,7 +161,7 @@ func (t testTextMapPropagator) Extract(ctx context.Context, carrier propagation.
 		return ctx
 	}
 
-	var exist = false
+	exist := false
 
 	for _, key := range carrier.Keys() {
 		if strings.EqualFold(testHeader, key) {

bridge/opentracing/internal/mock.go

@@ -54,8 +54,10 @@ type MockTracer struct {
 	rand     *rand.Rand
 }
 
-var _ trace.Tracer = &MockTracer{}
-var _ migration.DeferredContextSetupTracerExtension = &MockTracer{}
+var (
+	_ trace.Tracer                                  = &MockTracer{}
+	_ migration.DeferredContextSetupTracerExtension = &MockTracer{}
+)
 
 func NewMockTracer() *MockTracer {
 	return &MockTracer{
@@ -195,8 +197,10 @@ type MockSpan struct {
 	Events       []MockEvent
 }
 
-var _ trace.Span = &MockSpan{}
-var _ migration.OverrideTracerSpanExtension = &MockSpan{}
+var (
+	_ trace.Span                            = &MockSpan{}
+	_ migration.OverrideTracerSpanExtension = &MockSpan{}
+)
 
 func (s *MockSpan) SpanContext() trace.SpanContext {
 	return s.spanContext

bridge/opentracing/test/bridge_grpc_test.go

@@ -38,12 +38,15 @@ type testGRPCServer struct{}
 func (*testGRPCServer) UnaryCall(ctx context.Context, r *testpb.SimpleRequest) (*testpb.SimpleResponse, error) {
 	return &testpb.SimpleResponse{Payload: r.Payload * 2}, nil
 }
+
 func (*testGRPCServer) StreamingOutputCall(*testpb.SimpleRequest, testpb.TestService_StreamingOutputCallServer) error {
 	return nil
 }
+
 func (*testGRPCServer) StreamingInputCall(testpb.TestService_StreamingInputCallServer) error {
 	return nil
 }
+
 func (*testGRPCServer) StreamingBidirectionalCall(testpb.TestService_StreamingBidirectionalCallServer) error {
 	return nil
 }

bridge/opentracing/wrapper.go

@@ -60,8 +60,10 @@ type WrapperTracer struct {
 	tracer trace.Tracer
 }
 
-var _ trace.Tracer = &WrapperTracer{}
-var _ migration.DeferredContextSetupTracerExtension = &WrapperTracer{}
+var (
+	_ trace.Tracer                                  = &WrapperTracer{}
+	_ migration.DeferredContextSetupTracerExtension = &WrapperTracer{}
+)
 
 // NewWrapperTracer wraps the passed tracer and also talks to the
 // passed bridge tracer when setting up the context with the new

example/namedtracer/foo/foo.go

@@ -22,9 +22,7 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-var (
-	lemonsKey = attribute.Key("ex.com/lemons")
-)
+var lemonsKey = attribute.Key("ex.com/lemons")
 
 // SubOperation is an example to demonstrate the use of named tracer.
 // It creates a named tracer with its package path.

exporters/otlp/otlpmetric/otlpmetricgrpc/client_test.go

@@ -136,9 +136,11 @@ type clientShim struct {
 func (clientShim) Temporality(metric.InstrumentKind) metricdata.Temporality {
 	return metricdata.CumulativeTemporality
 }
+
 func (clientShim) Aggregation(metric.InstrumentKind) metric.Aggregation {
 	return nil
 }
+
 func (clientShim) ForceFlush(ctx context.Context) error {
 	return ctx.Err()
 }

exporters/otlp/otlpmetric/otlpmetricgrpc/internal/oconf/options_test.go

@@ -203,7 +203,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Metrics.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

exporters/otlp/otlpmetric/otlpmetricgrpc/internal/otest/client.go

@@ -38,7 +38,7 @@ import (
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	kvAlice = &cpb.KeyValue{Key: "user", Value: &cpb.AnyValue{

exporters/otlp/otlpmetric/otlpmetricgrpc/internal/transform/metricdata_test.go

@@ -40,7 +40,7 @@ type unknownAggT struct {
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	alice = attribute.NewSet(attribute.String("user", "alice"))

exporters/otlp/otlpmetric/otlpmetrichttp/client_test.go

@@ -40,9 +40,11 @@ type clientShim struct {
 func (clientShim) Temporality(metric.InstrumentKind) metricdata.Temporality {
 	return metricdata.CumulativeTemporality
 }
+
 func (clientShim) Aggregation(metric.InstrumentKind) metric.Aggregation {
 	return nil
 }
+
 func (clientShim) ForceFlush(ctx context.Context) error {
 	return ctx.Err()
 }

exporters/otlp/otlpmetric/otlpmetrichttp/internal/oconf/options_test.go

@@ -203,7 +203,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Metrics.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

exporters/otlp/otlpmetric/otlpmetrichttp/internal/otest/client.go

@@ -38,7 +38,7 @@ import (
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	kvAlice = &cpb.KeyValue{Key: "user", Value: &cpb.AnyValue{

exporters/otlp/otlpmetric/otlpmetrichttp/internal/transform/metricdata_test.go

@@ -40,7 +40,7 @@ type unknownAggT struct {
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	alice = attribute.NewSet(attribute.String("user", "alice"))

exporters/otlp/otlptrace/exporter.go

@@ -24,9 +24,7 @@ import (
 	tracesdk "go.opentelemetry.io/otel/sdk/trace"
 )
 
-var (
-	errAlreadyStarted = errors.New("already started")
-)
+var errAlreadyStarted = errors.New("already started")
 
 // Exporter exports trace data in the OTLP wire format.
 type Exporter struct {
@@ -55,7 +53,7 @@ func (e *Exporter) ExportSpans(ctx context.Context, ss []tracesdk.ReadOnlySpan)
 
 // Start establishes a connection to the receiving endpoint.
 func (e *Exporter) Start(ctx context.Context) error {
-	var err = errAlreadyStarted
+	err := errAlreadyStarted
 	e.startOnce.Do(func() {
 		e.mu.Lock()
 		e.started = true

exporters/otlp/otlptrace/internal/tracetransform/span_test.go

@@ -213,12 +213,14 @@ func TestSpanData(t *testing.T) {
 		StartTime: startTime,
 		EndTime:   endTime,
 		Events: []tracesdk.Event{
-			{Time: startTime,
+			{
+				Time: startTime,
 				Attributes: []attribute.KeyValue{
 					attribute.Int64("CompressedByteSize", 512),
 				},
 			},
-			{Time: endTime,
+			{
+				Time: endTime,
 				Attributes: []attribute.KeyValue{
 					attribute.String("EventType", "Recv"),
 				},

exporters/otlp/otlptrace/otlptracegrpc/internal/otlpconfig/options_test.go

@@ -201,7 +201,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Traces.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

exporters/otlp/otlptrace/otlptracehttp/example_test.go

@@ -32,12 +32,10 @@ const (
 	instrumentationVersion = "0.1.0"
 )
 
-var (
-	tracer = otel.GetTracerProvider().Tracer(
-		instrumentationName,
-		trace.WithInstrumentationVersion(instrumentationVersion),
-		trace.WithSchemaURL(semconv.SchemaURL),
-	)
+var tracer = otel.GetTracerProvider().Tracer(
+	instrumentationName,
+	trace.WithInstrumentationVersion(instrumentationVersion),
+	trace.WithSchemaURL(semconv.SchemaURL),
 )
 
 func add(ctx context.Context, x, y int64) int64 {

exporters/otlp/otlptrace/otlptracehttp/internal/otlpconfig/options_test.go

@@ -201,7 +201,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Traces.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

exporters/prometheus/exporter_test.go

@@ -746,7 +746,7 @@ func TestDuplicateMetrics(t *testing.T) {
 
 			tc.recordMetrics(ctx, meterA, meterB)
 
-			var match = false
+			match := false
 			for _, filename := range tc.possibleExpectedFiles {
 				file, ferr := os.Open(filename)
 				require.NoError(t, ferr)

exporters/stdout/stdoutmetric/example_test.go

@@ -31,7 +31,7 @@ import (
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	now = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	now = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 
 	res = resource.NewSchemaless(
 		semconv.ServiceName("stdoutmetric-example"),
@@ -158,7 +158,7 @@ func Example() {
 	// Ensure the periodic reader is cleaned up by shutting down the sdk.
 	_ = sdk.Shutdown(ctx)
 
-	//Output:
+	// Output:
 	// {
 	//   "Resource": [
 	//     {

exporters/stdout/stdoutmetric/exporter.go

@@ -106,9 +106,7 @@ func redactTimestamps(orig *metricdata.ResourceMetrics) {
 	}
 }
 
-var (
-	errUnknownAggType = errors.New("unknown aggregation type")
-)
+var errUnknownAggType = errors.New("unknown aggregation type")
 
 func redactAggregationTimestamps(orig metricdata.Aggregation) metricdata.Aggregation {
 	switch a := orig.(type) {

exporters/stdout/stdouttrace/example_test.go

@@ -32,12 +32,10 @@ const (
 	instrumentationVersion = "0.1.0"
 )
 
-var (
-	tracer = otel.GetTracerProvider().Tracer(
-		instrumentationName,
-		trace.WithInstrumentationVersion(instrumentationVersion),
-		trace.WithSchemaURL(semconv.SchemaURL),
-	)
+var tracer = otel.GetTracerProvider().Tracer(
+	instrumentationName,
+	trace.WithInstrumentationVersion(instrumentationVersion),
+	trace.WithSchemaURL(semconv.SchemaURL),
 )
 
 func add(ctx context.Context, x, y int64) int64 {

exporters/zipkin/internal/internaltest/harness.go

@@ -263,7 +263,7 @@ func (h *Harness) TestTracer(subjectFactory func() trace.Tracer) {
 }
 
 func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
-	var methods = map[string]func(span trace.Span){
+	methods := map[string]func(span trace.Span){
 		"#End": func(span trace.Span) {
 			span.End()
 		},
@@ -283,7 +283,7 @@ func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
 			span.SetAttributes(attribute.String("key1", "value"), attribute.Int("key2", 123))
 		},
 	}
-	var mechanisms = map[string]func() trace.Span{
+	mechanisms := map[string]func() trace.Span{
 		"Span created via Tracer#Start": func() trace.Span {
 			tracer := tracerFactory()
 			_, subject := tracer.Start(context.Background(), "test")

exporters/zipkin/internal/internaltest/text_map_carrier_test.go

@@ -22,9 +22,7 @@ import (
 	"testing"
 )
 
-var (
-	key, value = "test", "true"
-)
+var key, value = "test", "true"
 
 func TestTextMapCarrierKeys(t *testing.T) {
 	tmc := NewTextMapCarrier(map[string]string{key: value})

exporters/zipkin/internal/matchers/expectation.go

@@ -27,9 +27,7 @@ import (
 	"time"
 )
 
-var (
-	stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
-)
+var stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
 
 type Expectation struct {
 	t      *testing.T

internal/attribute/attribute_test.go

@@ -39,16 +39,20 @@ var wrapBoolSliceValue = func(v interface{}) interface{} {
 	}
 	return nil
 }
+
 var wrapStringSliceValue = func(v interface{}) interface{} {
 	if vi, ok := v.([]string); ok {
 		return StringSliceValue(vi)
 	}
 	return nil
 }
-var wrapAsBoolSlice = func(v interface{}) interface{} { return AsBoolSlice(v) }
-var wrapAsInt64Slice = func(v interface{}) interface{} { return AsInt64Slice(v) }
-var wrapAsFloat64Slice = func(v interface{}) interface{} { return AsFloat64Slice(v) }
-var wrapAsStringSlice = func(v interface{}) interface{} { return AsStringSlice(v) }
+
+var (
+	wrapAsBoolSlice    = func(v interface{}) interface{} { return AsBoolSlice(v) }
+	wrapAsInt64Slice   = func(v interface{}) interface{} { return AsInt64Slice(v) }
+	wrapAsFloat64Slice = func(v interface{}) interface{} { return AsFloat64Slice(v) }
+	wrapAsStringSlice  = func(v interface{}) interface{} { return AsStringSlice(v) }
+)
 
 func TestSliceValue(t *testing.T) {
 	type args struct {

internal/global/instruments.go

@@ -34,11 +34,13 @@ type afCounter struct {
 	name string
 	opts []metric.Float64ObservableCounterOption
 
-	delegate atomic.Value //metric.Float64ObservableCounter
+	delegate atomic.Value // metric.Float64ObservableCounter
 }
 
-var _ unwrapper = (*afCounter)(nil)
-var _ metric.Float64ObservableCounter = (*afCounter)(nil)
+var (
+	_ unwrapper                       = (*afCounter)(nil)
+	_ metric.Float64ObservableCounter = (*afCounter)(nil)
+)
 
 func (i *afCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableCounter(i.name, i.opts...)
@@ -63,11 +65,13 @@ type afUpDownCounter struct {
 	name string
 	opts []metric.Float64ObservableUpDownCounterOption
 
-	delegate atomic.Value //metric.Float64ObservableUpDownCounter
+	delegate atomic.Value // metric.Float64ObservableUpDownCounter
 }
 
-var _ unwrapper = (*afUpDownCounter)(nil)
-var _ metric.Float64ObservableUpDownCounter = (*afUpDownCounter)(nil)
+var (
+	_ unwrapper                             = (*afUpDownCounter)(nil)
+	_ metric.Float64ObservableUpDownCounter = (*afUpDownCounter)(nil)
+)
 
 func (i *afUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableUpDownCounter(i.name, i.opts...)
@@ -92,11 +96,13 @@ type afGauge struct {
 	name string
 	opts []metric.Float64ObservableGaugeOption
 
-	delegate atomic.Value //metric.Float64ObservableGauge
+	delegate atomic.Value // metric.Float64ObservableGauge
 }
 
-var _ unwrapper = (*afGauge)(nil)
-var _ metric.Float64ObservableGauge = (*afGauge)(nil)
+var (
+	_ unwrapper                     = (*afGauge)(nil)
+	_ metric.Float64ObservableGauge = (*afGauge)(nil)
+)
 
 func (i *afGauge) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableGauge(i.name, i.opts...)
@@ -121,11 +127,13 @@ type aiCounter struct {
 	name string
 	opts []metric.Int64ObservableCounterOption
 
-	delegate atomic.Value //metric.Int64ObservableCounter
+	delegate atomic.Value // metric.Int64ObservableCounter
 }
 
-var _ unwrapper = (*aiCounter)(nil)
-var _ metric.Int64ObservableCounter = (*aiCounter)(nil)
+var (
+	_ unwrapper                     = (*aiCounter)(nil)
+	_ metric.Int64ObservableCounter = (*aiCounter)(nil)
+)
 
 func (i *aiCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableCounter(i.name, i.opts...)
@@ -150,11 +158,13 @@ type aiUpDownCounter struct {
 	name string
 	opts []metric.Int64ObservableUpDownCounterOption
 
-	delegate atomic.Value //metric.Int64ObservableUpDownCounter
+	delegate atomic.Value // metric.Int64ObservableUpDownCounter
 }
 
-var _ unwrapper = (*aiUpDownCounter)(nil)
-var _ metric.Int64ObservableUpDownCounter = (*aiUpDownCounter)(nil)
+var (
+	_ unwrapper                           = (*aiUpDownCounter)(nil)
+	_ metric.Int64ObservableUpDownCounter = (*aiUpDownCounter)(nil)
+)
 
 func (i *aiUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableUpDownCounter(i.name, i.opts...)
@@ -179,11 +189,13 @@ type aiGauge struct {
 	name string
 	opts []metric.Int64ObservableGaugeOption
 
-	delegate atomic.Value //metric.Int64ObservableGauge
+	delegate atomic.Value // metric.Int64ObservableGauge
 }
 
-var _ unwrapper = (*aiGauge)(nil)
-var _ metric.Int64ObservableGauge = (*aiGauge)(nil)
+var (
+	_ unwrapper                   = (*aiGauge)(nil)
+	_ metric.Int64ObservableGauge = (*aiGauge)(nil)
+)
 
 func (i *aiGauge) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableGauge(i.name, i.opts...)
@@ -208,7 +220,7 @@ type sfCounter struct {
 	name string
 	opts []metric.Float64CounterOption
 
-	delegate atomic.Value //metric.Float64Counter
+	delegate atomic.Value // metric.Float64Counter
 }
 
 var _ metric.Float64Counter = (*sfCounter)(nil)
@@ -234,7 +246,7 @@ type sfUpDownCounter struct {
 	name string
 	opts []metric.Float64UpDownCounterOption
 
-	delegate atomic.Value //metric.Float64UpDownCounter
+	delegate atomic.Value // metric.Float64UpDownCounter
 }
 
 var _ metric.Float64UpDownCounter = (*sfUpDownCounter)(nil)
@@ -260,7 +272,7 @@ type sfHistogram struct {
 	name string
 	opts []metric.Float64HistogramOption
 
-	delegate atomic.Value //metric.Float64Histogram
+	delegate atomic.Value // metric.Float64Histogram
 }
 
 var _ metric.Float64Histogram = (*sfHistogram)(nil)
@@ -286,7 +298,7 @@ type siCounter struct {
 	name string
 	opts []metric.Int64CounterOption
 
-	delegate atomic.Value //metric.Int64Counter
+	delegate atomic.Value // metric.Int64Counter
 }
 
 var _ metric.Int64Counter = (*siCounter)(nil)
@@ -312,7 +324,7 @@ type siUpDownCounter struct {
 	name string
 	opts []metric.Int64UpDownCounterOption
 
-	delegate atomic.Value //metric.Int64UpDownCounter
+	delegate atomic.Value // metric.Int64UpDownCounter
 }
 
 var _ metric.Int64UpDownCounter = (*siUpDownCounter)(nil)
@@ -338,7 +350,7 @@ type siHistogram struct {
 	name string
 	opts []metric.Int64HistogramOption
 
-	delegate atomic.Value //metric.Int64Histogram
+	delegate atomic.Value // metric.Int64Histogram
 }
 
 var _ metric.Int64Histogram = (*siHistogram)(nil)

internal/global/instruments_test.go

@@ -168,9 +168,11 @@ type testCountingFloatInstrument struct {
 func (i *testCountingFloatInstrument) observe() {
 	i.count++
 }
+
 func (i *testCountingFloatInstrument) Add(context.Context, float64, ...metric.AddOption) {
 	i.count++
 }
+
 func (i *testCountingFloatInstrument) Record(context.Context, float64, ...metric.RecordOption) {
 	i.count++
 }
@@ -190,9 +192,11 @@ type testCountingIntInstrument struct {
 func (i *testCountingIntInstrument) observe() {
 	i.count++
 }
+
 func (i *testCountingIntInstrument) Add(context.Context, int64, ...metric.AddOption) {
 	i.count++
 }
+
 func (i *testCountingIntInstrument) Record(context.Context, int64, ...metric.RecordOption) {
 	i.count++
 }

internal/internaltest/harness.go

@@ -263,7 +263,7 @@ func (h *Harness) TestTracer(subjectFactory func() trace.Tracer) {
 }
 
 func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
-	var methods = map[string]func(span trace.Span){
+	methods := map[string]func(span trace.Span){
 		"#End": func(span trace.Span) {
 			span.End()
 		},
@@ -283,7 +283,7 @@ func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
 			span.SetAttributes(attribute.String("key1", "value"), attribute.Int("key2", 123))
 		},
 	}
-	var mechanisms = map[string]func() trace.Span{
+	mechanisms := map[string]func() trace.Span{
 		"Span created via Tracer#Start": func() trace.Span {
 			tracer := tracerFactory()
 			_, subject := tracer.Start(context.Background(), "test")

internal/internaltest/text_map_carrier_test.go

@@ -22,9 +22,7 @@ import (
 	"testing"
 )
 
-var (
-	key, value = "test", "true"
-)
+var key, value = "test", "true"
 
 func TestTextMapCarrierKeys(t *testing.T) {
 	tmc := NewTextMapCarrier(map[string]string{key: value})

internal/matchers/expectation.go

@@ -27,9 +27,7 @@ import (
 	"time"
 )
 
-var (
-	stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
-)
+var stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
 
 type Expectation struct {
 	t      *testing.T

internal/shared/internaltest/harness.go.tmpl

@@ -263,7 +263,7 @@ func (h *Harness) TestTracer(subjectFactory func() trace.Tracer) {
 }
 
 func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
-	var methods = map[string]func(span trace.Span){
+	methods := map[string]func(span trace.Span){
 		"#End": func(span trace.Span) {
 			span.End()
 		},
@@ -283,7 +283,7 @@ func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
 			span.SetAttributes(attribute.String("key1", "value"), attribute.Int("key2", 123))
 		},
 	}
-	var mechanisms = map[string]func() trace.Span{
+	mechanisms := map[string]func() trace.Span{
 		"Span created via Tracer#Start": func() trace.Span {
 			tracer := tracerFactory()
 			_, subject := tracer.Start(context.Background(), "test")

internal/shared/internaltest/text_map_carrier_test.go.tmpl

@@ -22,9 +22,7 @@ import (
 	"testing"
 )
 
-var (
-	key, value = "test", "true"
-)
+var key, value = "test", "true"
 
 func TestTextMapCarrierKeys(t *testing.T) {
 	tmc := NewTextMapCarrier(map[string]string{key: value})

internal/shared/matchers/expectation.go.tmpl

@@ -27,9 +27,7 @@ import (
 	"time"
 )
 
-var (
-	stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
-)
+var stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
 
 type Expectation struct {
 	t      *testing.T

internal/shared/otlp/otlpmetric/oconf/options_test.go.tmpl

@@ -203,7 +203,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Metrics.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

internal/shared/otlp/otlpmetric/otest/client.go.tmpl

@@ -38,7 +38,7 @@ import (
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	kvAlice = &cpb.KeyValue{Key: "user", Value: &cpb.AnyValue{

internal/shared/otlp/otlpmetric/transform/metricdata_test.go.tmpl

@@ -40,7 +40,7 @@ type unknownAggT struct {
 
 var (
 	// Sat Jan 01 2000 00:00:00 GMT+0000.
-	start = time.Date(2000, time.January, 01, 0, 0, 0, 0, time.FixedZone("GMT", 0))
+	start = time.Date(2000, time.January, 0o1, 0, 0, 0, 0, time.FixedZone("GMT", 0))
 	end   = start.Add(30 * time.Second)
 
 	alice = attribute.NewSet(attribute.String("user", "alice"))

internal/shared/otlp/otlptrace/otlpconfig/options_test.go.tmpl

@@ -201,7 +201,7 @@ func TestConfigs(t *testing.T) {
 			},
 			asserts: func(t *testing.T, c *Config, grpcOption bool) {
 				if grpcOption {
-					//TODO: make sure gRPC's credentials actually works
+					// TODO: make sure gRPC's credentials actually works
 					assert.NotNil(t, c.Traces.GRPCCredentials)
 				} else {
 					// nolint:staticcheck // ignoring tlsCert.RootCAs.Subjects is deprecated ERR because cert does not come from SystemCertPool.

propagation/propagation_test.go

@@ -27,9 +27,7 @@ import (
 
 type ctxKeyType uint
 
-var (
-	ctxKey ctxKeyType
-)
+var ctxKey ctxKeyType
 
 type carrier []string
 

propagation/trace_context.go

@@ -40,8 +40,10 @@ const (
 // their proprietary information.
 type TraceContext struct{}
 
-var _ TextMapPropagator = TraceContext{}
-var traceCtxRegExp = regexp.MustCompile("^(?P<version>[0-9a-f]{2})-(?P<traceID>[a-f0-9]{32})-(?P<spanID>[a-f0-9]{16})-(?P<traceFlags>[a-f0-9]{2})(?:-.*)?$")
+var (
+	_              TextMapPropagator = TraceContext{}
+	traceCtxRegExp                   = regexp.MustCompile("^(?P<version>[0-9a-f]{2})-(?P<traceID>[a-f0-9]{32})-(?P<spanID>[a-f0-9]{16})-(?P<traceFlags>[a-f0-9]{2})(?:-.*)?$")
+)
 
 // Inject set tracecontext from the Context into the carrier.
 func (tc TraceContext) Inject(ctx context.Context, carrier TextMapCarrier) {

sdk/internal/internaltest/harness.go

@@ -263,7 +263,7 @@ func (h *Harness) TestTracer(subjectFactory func() trace.Tracer) {
 }
 
 func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
-	var methods = map[string]func(span trace.Span){
+	methods := map[string]func(span trace.Span){
 		"#End": func(span trace.Span) {
 			span.End()
 		},
@@ -283,7 +283,7 @@ func (h *Harness) testSpan(tracerFactory func() trace.Tracer) {
 			span.SetAttributes(attribute.String("key1", "value"), attribute.Int("key2", 123))
 		},
 	}
-	var mechanisms = map[string]func() trace.Span{
+	mechanisms := map[string]func() trace.Span{
 		"Span created via Tracer#Start": func() trace.Span {
 			tracer := tracerFactory()
 			_, subject := tracer.Start(context.Background(), "test")

sdk/internal/internaltest/text_map_carrier_test.go

@@ -22,9 +22,7 @@ import (
 	"testing"
 )
 
-var (
-	key, value = "test", "true"
-)
+var key, value = "test", "true"
 
 func TestTextMapCarrierKeys(t *testing.T) {
 	tmc := NewTextMapCarrier(map[string]string{key: value})

sdk/internal/matchers/expectation.go

@@ -27,9 +27,7 @@ import (
 	"time"
 )
 
-var (
-	stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
-)
+var stackTracePruneRE = regexp.MustCompile(`runtime\/debug|testing|internal\/matchers`)
 
 type Expectation struct {
 	t      *testing.T

sdk/metric/config_test.go

@@ -47,6 +47,7 @@ func (r *reader) RegisterProducer(p Producer) { r.externalProducers = append(r.e
 func (r *reader) temporality(kind InstrumentKind) metricdata.Temporality {
 	return r.temporalityFunc(kind)
 }
+
 func (r *reader) Collect(ctx context.Context, rm *metricdata.ResourceMetrics) error {
 	return r.collectFunc(ctx, rm)
 }

sdk/metric/instrument.go

@@ -188,9 +188,11 @@ type int64Inst struct {
 	embedded.Int64Histogram
 }
 
-var _ metric.Int64Counter = (*int64Inst)(nil)
-var _ metric.Int64UpDownCounter = (*int64Inst)(nil)
-var _ metric.Int64Histogram = (*int64Inst)(nil)
+var (
+	_ metric.Int64Counter       = (*int64Inst)(nil)
+	_ metric.Int64UpDownCounter = (*int64Inst)(nil)
+	_ metric.Int64Histogram     = (*int64Inst)(nil)
+)
 
 func (i *int64Inst) Add(ctx context.Context, val int64, opts ...metric.AddOption) {
 	c := metric.NewAddConfig(opts)
@@ -219,9 +221,11 @@ type float64Inst struct {
 	embedded.Float64Histogram
 }
 
-var _ metric.Float64Counter = (*float64Inst)(nil)
-var _ metric.Float64UpDownCounter = (*float64Inst)(nil)
-var _ metric.Float64Histogram = (*float64Inst)(nil)
+var (
+	_ metric.Float64Counter       = (*float64Inst)(nil)
+	_ metric.Float64UpDownCounter = (*float64Inst)(nil)
+	_ metric.Float64Histogram     = (*float64Inst)(nil)
+)
 
 func (i *float64Inst) Add(ctx context.Context, val float64, opts ...metric.AddOption) {
 	c := metric.NewAddConfig(opts)
@@ -260,9 +264,11 @@ type float64Observable struct {
 	embedded.Float64ObservableGauge
 }
 
-var _ metric.Float64ObservableCounter = float64Observable{}
-var _ metric.Float64ObservableUpDownCounter = float64Observable{}
-var _ metric.Float64ObservableGauge = float64Observable{}
+var (
+	_ metric.Float64ObservableCounter       = float64Observable{}
+	_ metric.Float64ObservableUpDownCounter = float64Observable{}
+	_ metric.Float64ObservableGauge         = float64Observable{}
+)
 
 func newFloat64Observable(m *meter, kind InstrumentKind, name, desc, u string, meas []aggregate.Measure[float64]) float64Observable {
 	return float64Observable{
@@ -279,9 +285,11 @@ type int64Observable struct {
 	embedded.Int64ObservableGauge
 }
 
-var _ metric.Int64ObservableCounter = int64Observable{}
-var _ metric.Int64ObservableUpDownCounter = int64Observable{}
-var _ metric.Int64ObservableGauge = int64Observable{}
+var (
+	_ metric.Int64ObservableCounter       = int64Observable{}
+	_ metric.Int64ObservableUpDownCounter = int64Observable{}
+	_ metric.Int64ObservableGauge         = int64Observable{}
+)
 
 func newInt64Observable(m *meter, kind InstrumentKind, name, desc, u string, meas []aggregate.Measure[int64]) int64Observable {
 	return int64Observable{

sdk/metric/internal/aggregate/exponential_histogram.go

@@ -113,7 +113,7 @@ func (p *expoHistogramDataPoint[N]) record(v N) {
 			otel.Handle(errors.New("exponential histogram scale underflow"))
 			return
 		}
-		//Downscale
+		// Downscale
 		p.scale -= scaleDelta
 		p.posBuckets.downscale(scaleDelta)
 		p.negBuckets.downscale(scaleDelta)

sdk/metric/manual_reader_test.go

@@ -40,8 +40,10 @@ func BenchmarkManualReader(b *testing.B) {
 	b.Run("Collect", benchReaderCollectFunc(NewManualReader()))
 }
 
-var deltaTemporalitySelector = func(InstrumentKind) metricdata.Temporality { return metricdata.DeltaTemporality }
-var cumulativeTemporalitySelector = func(InstrumentKind) metricdata.Temporality { return metricdata.CumulativeTemporality }
+var (
+	deltaTemporalitySelector      = func(InstrumentKind) metricdata.Temporality { return metricdata.DeltaTemporality }
+	cumulativeTemporalitySelector = func(InstrumentKind) metricdata.Temporality { return metricdata.CumulativeTemporality }
+)
 
 func TestManualReaderTemporality(t *testing.T) {
 	tests := []struct {

sdk/metric/meter.go

@@ -26,11 +26,9 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 )
 
-var (
-	// ErrInstrumentName indicates the created instrument has an invalid name.
-	// Valid names must consist of 255 or fewer characters including alphanumeric, _, ., -, / and start with a letter.
-	ErrInstrumentName = errors.New("invalid instrument name")
-)
+// ErrInstrumentName indicates the created instrument has an invalid name.
+// Valid names must consist of 255 or fewer characters including alphanumeric, _, ., -, / and start with a letter.
+var ErrInstrumentName = errors.New("invalid instrument name")
 
 // meter handles the creation and coordination of all metric instruments. A
 // meter represents a single instrumentation scope; all metric telemetry
@@ -268,9 +266,11 @@ func validateInstrumentName(name string) error {
 	}
 	return nil
 }
+
 func isAlpha(c rune) bool {
 	return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z')
 }
+
 func isAlphanumeric(c rune) bool {
 	return isAlpha(c) || ('0' <= c && c <= '9')
 }

sdk/metric/meter_test.go

@@ -1826,12 +1826,15 @@ func BenchmarkInstrumentCreation(b *testing.B) {
 func testNilAggregationSelector(InstrumentKind) Aggregation {
 	return nil
 }
+
 func testDefaultAggregationSelector(InstrumentKind) Aggregation {
 	return AggregationDefault{}
 }
+
 func testUndefinedTemporalitySelector(InstrumentKind) metricdata.Temporality {
 	return metricdata.Temporality(0)
 }
+
 func testInvalidTemporalitySelector(InstrumentKind) metricdata.Temporality {
 	return metricdata.Temporality(255)
 }

sdk/metric/metricdata/metricdatatest/comparisons.go

@@ -741,6 +741,7 @@ func hasAttributesScopeMetrics(sm metricdata.ScopeMetrics, attrs ...attribute.Ke
 	}
 	return reasons
 }
+
 func hasAttributesResourceMetrics(rm metricdata.ResourceMetrics, attrs ...attribute.KeyValue) (reasons []string) {
 	for n, sm := range rm.ScopeMetrics {
 		reas := hasAttributesScopeMetrics(sm, attrs...)

sdk/metric/periodic_reader.go

@@ -127,7 +127,8 @@ func NewPeriodicReader(exporter Exporter, options ...PeriodicReaderOption) *Peri
 		rmPool: sync.Pool{
 			New: func() interface{} {
 				return &metricdata.ResourceMetrics{}
-			}},
+			},
+		},
 	}
 	r.externalProducers.Store(conf.producers)
 

sdk/metric/periodic_reader_test.go

@@ -344,7 +344,8 @@ func TestPeriodicReaderFlushesPending(t *testing.T) {
 					return ctx.Err()
 				}
 				return nil
-			}})
+			},
+		})
 		assert.ErrorIs(t, r.ForceFlush(context.Background()), context.DeadlineExceeded)
 		assert.False(t, *called, "exporter Export method called when it should have failed before export")
 
@@ -396,7 +397,8 @@ func TestPeriodicReaderFlushesPending(t *testing.T) {
 					return ctx.Err()
 				}
 				return nil
-			}})
+			},
+		})
 		assert.ErrorIs(t, r.Shutdown(context.Background()), context.DeadlineExceeded)
 		assert.False(t, *called, "exporter Export method called when it should have failed before export")
 	})

sdk/metric/pipeline_registry_test.go

@@ -39,6 +39,7 @@ type invalidAggregation struct{}
 func (invalidAggregation) copy() Aggregation {
 	return invalidAggregation{}
 }
+
 func (invalidAggregation) err() error {
 	return nil
 }
@@ -155,7 +156,7 @@ func testCreateAggregators[N int64 | float64](t *testing.T) {
 	)
 
 	instruments := []Instrument{
-		{Name: "foo", Kind: InstrumentKind(0)}, //Unknown kind
+		{Name: "foo", Kind: InstrumentKind(0)}, // Unknown kind
 		{Name: "foo", Kind: InstrumentKindCounter},
 		{Name: "foo", Kind: InstrumentKindUpDownCounter},
 		{Name: "foo", Kind: InstrumentKindHistogram},

sdk/metric/reader_test.go

@@ -138,7 +138,8 @@ func (ts *readerTestSuite) TestSDKFailureBlocksExternalProducer() {
 		produceFunc: func(ctx context.Context, rm *metricdata.ResourceMetrics) error {
 			*rm = metricdata.ResourceMetrics{}
 			return assert.AnError
-		}})
+		},
+	})
 
 	m := metricdata.ResourceMetrics{}
 	err := ts.Reader.Collect(context.Background(), &m)

sdk/resource/auto.go

@@ -21,12 +21,10 @@ import (
 	"strings"
 )
 
-var (
-	// ErrPartialResource is returned by a detector when complete source
-	// information for a Resource is unavailable or the source information
-	// contains invalid values that are omitted from the returned Resource.
-	ErrPartialResource = errors.New("partial resource")
-)
+// ErrPartialResource is returned by a detector when complete source
+// information for a Resource is unavailable or the source information
+// contains invalid values that are omitted from the returned Resource.
+var ErrPartialResource = errors.New("partial resource")
 
 // Detector detects OpenTelemetry resource information.
 type Detector interface {

sdk/resource/benchmark_test.go

@@ -63,21 +63,27 @@ func benchmarkMergeResource(b *testing.B, size int) {
 func BenchmarkMergeResource_1(b *testing.B) {
 	benchmarkMergeResource(b, 1)
 }
+
 func BenchmarkMergeResource_2(b *testing.B) {
 	benchmarkMergeResource(b, 2)
 }
+
 func BenchmarkMergeResource_3(b *testing.B) {
 	benchmarkMergeResource(b, 3)
 }
+
 func BenchmarkMergeResource_4(b *testing.B) {
 	benchmarkMergeResource(b, 4)
 }
+
 func BenchmarkMergeResource_6(b *testing.B) {
 	benchmarkMergeResource(b, 6)
 }
+
 func BenchmarkMergeResource_8(b *testing.B) {
 	benchmarkMergeResource(b, 8)
 }
+
 func BenchmarkMergeResource_16(b *testing.B) {
 	benchmarkMergeResource(b, 16)
 }

sdk/resource/env.go

@@ -34,10 +34,8 @@ const (
 	svcNameKey = "OTEL_SERVICE_NAME"
 )
 
-var (
-	// errMissingValue is returned when a resource value is missing.
-	errMissingValue = fmt.Errorf("%w: missing value", ErrPartialResource)
-)
+// errMissingValue is returned when a resource value is missing.
+var errMissingValue = fmt.Errorf("%w: missing value", ErrPartialResource)
 
 // fromEnv is a Detector that implements the Detector and collects
 // resources from environment.  This Detector is included as a

sdk/resource/export_test.go

@@ -34,6 +34,4 @@ var (
 	RuntimeArch = runtimeArch
 )
 
-var (
-	MapRuntimeOSToSemconvOSType = mapRuntimeOSToSemconvOSType
-)
+var MapRuntimeOSToSemconvOSType = mapRuntimeOSToSemconvOSType

sdk/resource/os.go

@@ -36,8 +36,10 @@ func setOSDescriptionProvider(osDescriptionProvider osDescriptionProvider) {
 	osDescription = osDescriptionProvider
 }
 
-type osTypeDetector struct{}
-type osDescriptionDetector struct{}
+type (
+	osTypeDetector        struct{}
+	osDescriptionDetector struct{}
+)
 
 // Detect returns a *Resource that describes the operating system type the
 // service is running on.
@@ -56,7 +58,6 @@ func (osTypeDetector) Detect(ctx context.Context) (*Resource, error) {
 // service is running on.
 func (osDescriptionDetector) Detect(ctx context.Context) (*Resource, error) {
 	description, err := osDescription()
-
 	if err != nil {
 		return nil, err
 	}

sdk/resource/process.go

@@ -25,14 +25,16 @@ import (
 	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
 )
 
-type pidProvider func() int
-type executablePathProvider func() (string, error)
-type commandArgsProvider func() []string
-type ownerProvider func() (*user.User, error)
-type runtimeNameProvider func() string
-type runtimeVersionProvider func() string
-type runtimeOSProvider func() string
-type runtimeArchProvider func() string
+type (
+	pidProvider            func() int
+	executablePathProvider func() (string, error)
+	commandArgsProvider    func() []string
+	ownerProvider          func() (*user.User, error)
+	runtimeNameProvider    func() string
+	runtimeVersionProvider func() string
+	runtimeOSProvider      func() string
+	runtimeArchProvider    func() string
+)
 
 var (
 	defaultPidProvider            pidProvider            = os.Getpid
@@ -108,14 +110,16 @@ func setUserProviders(ownerProvider ownerProvider) {
 	owner = ownerProvider
 }
 
-type processPIDDetector struct{}
-type processExecutableNameDetector struct{}
-type processExecutablePathDetector struct{}
-type processCommandArgsDetector struct{}
-type processOwnerDetector struct{}
-type processRuntimeNameDetector struct{}
-type processRuntimeVersionDetector struct{}
-type processRuntimeDescriptionDetector struct{}
+type (
+	processPIDDetector                struct{}
+	processExecutableNameDetector     struct{}
+	processExecutablePathDetector     struct{}
+	processCommandArgsDetector        struct{}
+	processOwnerDetector              struct{}
+	processRuntimeNameDetector        struct{}
+	processRuntimeVersionDetector     struct{}
+	processRuntimeDescriptionDetector struct{}
+)
 
 // Detect returns a *Resource that describes the process identifier (PID) of the
 // executing process.

sdk/trace/benchmark_test.go

@@ -285,6 +285,7 @@ func BenchmarkSpanWithEvents_WithStackTrace(b *testing.B) {
 		}
 	})
 }
+
 func BenchmarkSpanWithEvents_WithTimestamp(b *testing.B) {
 	traceBenchmark(b, "Benchmark Start With 4 Attributes", func(b *testing.B, t trace.Tracer) {
 		ctx := context.Background()

sdk/trace/span.go

@@ -158,8 +158,10 @@ type recordingSpan struct {
 	tracer *tracer
 }
 
-var _ ReadWriteSpan = (*recordingSpan)(nil)
-var _ runtimeTracer = (*recordingSpan)(nil)
+var (
+	_ ReadWriteSpan = (*recordingSpan)(nil)
+	_ runtimeTracer = (*recordingSpan)(nil)
+)
 
 // SpanContext returns the SpanContext of this span.
 func (s *recordingSpan) SpanContext() trace.SpanContext {

sdk/trace/span_processor_filter_example_test.go

@@ -66,6 +66,7 @@ func (f InstrumentationBlacklist) Shutdown(ctx context.Context) error { return f
 func (f InstrumentationBlacklist) ForceFlush(ctx context.Context) error {
 	return f.Next.ForceFlush(ctx)
 }
+
 func (f InstrumentationBlacklist) OnEnd(s ReadOnlySpan) {
 	if f.Blacklist != nil && f.Blacklist[s.InstrumentationScope().Name] {
 		// Drop spans from this instrumentation

sdk/trace/trace_test.go

@@ -1407,7 +1407,8 @@ func TestWithResource(t *testing.T) {
 			name: "last resource wins",
 			options: []TracerProviderOption{
 				WithResource(resource.NewSchemaless(attribute.String("rk1", "vk1"), attribute.Int64("rk2", 5))),
-				WithResource(resource.NewSchemaless(attribute.String("rk3", "rv3"), attribute.Int64("rk4", 10)))},
+				WithResource(resource.NewSchemaless(attribute.String("rk3", "rv3"), attribute.Int64("rk4", 10))),
+			},
 			want: mergeResource(t, resource.Environment(), resource.NewSchemaless(attribute.String("rk3", "rv3"), attribute.Int64("rk4", 10))),
 		},
 		{

sdk/trace/tracetest/span.go

@@ -162,6 +162,7 @@ func (s spanSnapshot) Resource() *resource.Resource     { return s.resource }
 func (s spanSnapshot) InstrumentationScope() instrumentation.Scope {
 	return s.instrumentationScope
 }
+
 func (s spanSnapshot) InstrumentationLibrary() instrumentation.Library {
 	return s.instrumentationScope
 }

trace/config.go

@@ -268,6 +268,7 @@ func (o stackTraceOption) applyEvent(c EventConfig) EventConfig {
 	c.stackTrace = bool(o)
 	return c
 }
+
 func (o stackTraceOption) applySpan(c SpanConfig) SpanConfig {
 	c.stackTrace = bool(o)
 	return c

trace/trace.go

@@ -48,8 +48,10 @@ func (e errorConst) Error() string {
 // nolint:revive // revive complains about stutter of `trace.TraceID`.
 type TraceID [16]byte
 
-var nilTraceID TraceID
-var _ json.Marshaler = nilTraceID
+var (
+	nilTraceID TraceID
+	_          json.Marshaler = nilTraceID
+)
 
 // IsValid checks whether the trace TraceID is valid. A valid trace ID does
 // not consist of zeros only.
@@ -71,8 +73,10 @@ func (t TraceID) String() string {
 // SpanID is a unique identity of a span in a trace.
 type SpanID [8]byte
 
-var nilSpanID SpanID
-var _ json.Marshaler = nilSpanID
+var (
+	nilSpanID SpanID
+	_         json.Marshaler = nilSpanID
+)
 
 // IsValid checks whether the SpanID is valid. A valid SpanID does not consist
 // of zeros only.

trace/trace_test.go

@@ -309,7 +309,7 @@ func TestSpanContextHasTraceID(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//proto: func (sc SpanContext) HasTraceID() bool{}
+			// proto: func (sc SpanContext) HasTraceID() bool{}
 			sc := SpanContext{traceID: testcase.tid}
 			have := sc.HasTraceID()
 			if have != testcase.want {
@@ -336,7 +336,7 @@ func TestSpanContextHasSpanID(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//proto: func (sc SpanContext) HasSpanID() bool {}
+			// proto: func (sc SpanContext) HasSpanID() bool {}
 			have := testcase.sc.HasSpanID()
 			if have != testcase.want {
 				t.Errorf("Want: %v, but have: %v", testcase.want, have)
@@ -435,7 +435,7 @@ func TestStringTraceID(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//proto: func (t TraceID) String() string {}
+			// proto: func (t TraceID) String() string {}
 			have := testcase.tid.String()
 			if have != testcase.want {
 				t.Errorf("Want: %s, but have: %s", testcase.want, have)
@@ -462,7 +462,7 @@ func TestStringSpanID(t *testing.T) {
 		},
 	} {
 		t.Run(testcase.name, func(t *testing.T) {
-			//proto: func (t TraceID) String() string {}
+			// proto: func (t TraceID) String() string {}
 			have := testcase.sid.String()
 			if have != testcase.want {
 				t.Errorf("Want: %s, but have: %s", testcase.want, have)
@@ -481,17 +481,14 @@ func TestValidateSpanKind(t *testing.T) {
 			SpanKindInternal,
 		},
 		{
-
 			SpanKindInternal,
 			SpanKindInternal,
 		},
 		{
-
 			SpanKindServer,
 			SpanKindServer,
 		},
 		{
-
 			SpanKindClient,
 			SpanKindClient,
 		},
@@ -521,17 +518,14 @@ func TestSpanKindString(t *testing.T) {
 			"unspecified",
 		},
 		{
-
 			SpanKindInternal,
 			"internal",
 		},
 		{
-
 			SpanKindServer,
 			"server",
 		},
 		{
-
 			SpanKindClient,
 			"client",
 		},

trace/tracestate_test.go

@@ -495,7 +495,8 @@ func TestTraceStateInsert(t *testing.T) {
 					),
 				}
 			}(),
-		}}
+		},
+	}
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {