go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0: WithReconnectionPeriod

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify WithReconnectionPeriod in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0
Demonstrate these symbols/APIs:
  - WithReconnectionPeriod

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:88b93a5579be97d818663652e8e4cc9ab409b5ee62d971a9bd190bfec95291a1","contract":["WithReconnectionPeriod creates option that configures reconnection period for OTLP trace client","WithReconnectionPeriod accepts various reconnection duration values without error","WithReconnectionPeriod with local gRPC server exports trace spans successfully","Exported spans over connection configured with WithReconnectionPeriod preserve trace structure and attributes","Exporter and tracer provider shutdown flushes pending spans cleanly"],"goal":"verify WithReconnectionPeriod in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0"],"schemaVersion":1,"symbols":["WithReconnectionPeriod"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","moduleSystem":"go.mod","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0","symbols":["WithReconnectionPeriod"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	go.opentelemetry.io/otel v1.43.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0
	go.opentelemetry.io/otel/sdk v1.43.0
	go.opentelemetry.io/otel/trace v1.43.0
	go.opentelemetry.io/proto/otlp v1.10.0
	google.golang.org/grpc v1.80.0
)

require (
	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/uuid v1.6.0 // indirect
	github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel/metric v1.43.0 // indirect
	golang.org/x/net v0.52.0 // indirect
	golang.org/x/sys v0.42.0 // indirect
	golang.org/x/text v0.35.0 // indirect
	google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
	google.golang.org/protobuf v1.36.11 // indirect
)

github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 h1:HWRh5R2+9EifMyIHV7ZV+MIZqgz+PMpZ14Jynv3O2Zs=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0/go.mod h1:JfhWUomR1baixubs02l85lZYYOm7LV6om4ceouMv45c=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/otel v1.43.0 h1:mYIM03dnh5zfN7HautFE4ieIig9amkNANT+xcVxAj9I=
go.opentelemetry.io/otel v1.43.0/go.mod h1:JuG+u74mvjvcm8vj8pI5XiHy1zDeoCS2LB1spIq7Ay0=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0 h1:88Y4s2C8oTui1LGM6bTWkw0ICGcOLCAI5l6zsD1j20k=
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0/go.mod h1:Vl1/iaggsuRlrHf/hfPJPvVag77kKyvrLeD10kpMl+A=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0 h1:RAE+JPfvEmvy+0LzyUA25/SGawPwIUbZ6u0Wug54sLc=
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0/go.mod h1:AGmbycVGEsRx9mXMZ75CsOyhSP6MFIcj/6dnG+vhVjk=
go.opentelemetry.io/otel/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
go.opentelemetry.io/otel/sdk v1.43.0 h1:pi5mE86i5rTeLXqoF/hhiBtUNcrAGHLKQdhg4h4V9Dg=
go.opentelemetry.io/otel/sdk v1.43.0/go.mod h1:P+IkVU3iWukmiit/Yf9AWvpyRDlUeBaRg6Y+C58QHzg=
go.opentelemetry.io/otel/sdk/metric v1.43.0 h1:S88dyqXjJkuBNLeMcVPRFXpRw2fuwdvfCGLEo89fDkw=
go.opentelemetry.io/otel/sdk/metric v1.43.0/go.mod h1:C/RJtwSEJ5hzTiUz5pXF1kILHStzb9zFlIEe85bhj6A=
go.opentelemetry.io/otel/trace v1.43.0 h1:BkNrHpup+4k4w+ZZ86CZoHHEkohws8AY+WTX09nk+3A=
go.opentelemetry.io/otel/trace v1.43.0/go.mod h1:/QJhyVBUUswCphDVxq+8mld+AvhXZLhe+8WVFxiFff0=
go.opentelemetry.io/proto/otlp v1.10.0 h1:IQRWgT5srOCYfiWnpqUYz9CVmbO8bFmKcwYxpuCSL2g=
go.opentelemetry.io/proto/otlp v1.10.0/go.mod h1:/CV4QoCR/S9yaPj8utp3lvQPoqMtxXdzn7ozvvozVqk=
go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
gonum.org/v1/gonum v0.17.0 h1:VbpOemQlsSMrYmn7T2OUvQ4dqxQXU+ouZFQsZOx50z4=
gonum.org/v1/gonum v0.17.0/go.mod h1:El3tOrEuMpv2UdMrbNlKEh9vd86bmQ6vqIcDwxEOc1E=
google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 h1:VPWxll4HlMw1Vs/qXtN7BvhZqsS9cdAittCNvVENElA=
google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:7QBABkRtR8z+TEnmXTqIqwJLlzrZKVfAUm7tY3yGv0M=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 h1:m8qni9SQFH0tJc1X0vmnpw/0t+AImlSvp30sEupozUg=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"context"
	"fmt"
	"time"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
	"go.opentelemetry.io/otel/trace"
)

// ExporterConfig defines configuration options for creating an OTLP trace gRPC exporter.
type ExporterConfig struct {
	Endpoint           string
	Insecure           bool
	ReconnectionPeriod time.Duration
	Headers            map[string]string
	Timeout            time.Duration
	Compressor         string
	Options            []otlptracegrpc.Option
}

// BuildClientOptions constructs a slice of otlptracegrpc.Option from the given config,
// applying WithReconnectionPeriod if specified.
func BuildClientOptions(cfg ExporterConfig) []otlptracegrpc.Option {
	var opts []otlptracegrpc.Option

	if cfg.Endpoint != "" {
		opts = append(opts, otlptracegrpc.WithEndpoint(cfg.Endpoint))
	}
	if cfg.Insecure {
		opts = append(opts, otlptracegrpc.WithInsecure())
	}
	if cfg.ReconnectionPeriod > 0 {
		opts = append(opts, otlptracegrpc.WithReconnectionPeriod(cfg.ReconnectionPeriod))
	}
	if len(cfg.Headers) > 0 {
		opts = append(opts, otlptracegrpc.WithHeaders(cfg.Headers))
	}
	if cfg.Timeout > 0 {
		opts = append(opts, otlptracegrpc.WithTimeout(cfg.Timeout))
	}
	if cfg.Compressor != "" {
		opts = append(opts, otlptracegrpc.WithCompressor(cfg.Compressor))
	}
	if len(cfg.Options) > 0 {
		opts = append(opts, cfg.Options...)
	}

	return opts
}

// NewTraceClient creates an otlptrace.Client configured with reconnection period and options.
func NewTraceClient(cfg ExporterConfig) otlptrace.Client {
	opts := BuildClientOptions(cfg)
	return otlptracegrpc.NewClient(opts...)
}

// NewExporter creates and starts a new OTLP gRPC trace exporter with the given configuration.
func NewExporter(ctx context.Context, cfg ExporterConfig) (*otlptrace.Exporter, error) {
	opts := BuildClientOptions(cfg)
	exp, err := otlptracegrpc.New(ctx, opts...)
	if err != nil {
		return nil, fmt.Errorf("failed to create otlptracegrpc exporter: %w", err)
	}
	return exp, nil
}

// NewTracerProvider creates a TracerProvider configured with the given OTLP trace exporter.
func NewTracerProvider(ctx context.Context, exp sdktrace.SpanExporter, serviceName string) (*sdktrace.TracerProvider, error) {
	res, err := resource.New(ctx,
		resource.WithAttributes(
			semconv.ServiceNameKey.String(serviceName),
			attribute.String("environment", "test"),
		),
	)
	if err != nil {
		return nil, fmt.Errorf("failed to create resource: %w", err)
	}

	tp := sdktrace.NewTracerProvider(
		sdktrace.WithSyncer(exp),
		sdktrace.WithResource(res),
	)
	return tp, nil
}

// EmitSampleSpan creates and finishes a sample trace span using the provided TracerProvider.
func EmitSampleSpan(ctx context.Context, tp *sdktrace.TracerProvider, tracerName, spanName string, attrs ...attribute.KeyValue) (context.Context, trace.Span) {
	tr := tp.Tracer(tracerName)
	ctx, span := tr.Start(ctx, spanName, trace.WithAttributes(attrs...))
	span.End()
	return ctx, span
}

{
  "schemaVersion": 1,
  "goal": "verify WithReconnectionPeriod in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc@v1.43.0"
  ],
  "symbols": [
    "WithReconnectionPeriod"
  ]
}

package main

import (
	"context"
	"fmt"
	"net"
	"os"
	"sync"
	"time"

	"sample"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	coltracepb "go.opentelemetry.io/proto/otlp/collector/trace/v1"
	tracepb "go.opentelemetry.io/proto/otlp/trace/v1"
	"google.golang.org/grpc"
)

type mockTraceServer struct {
	coltracepb.UnimplementedTraceServiceServer
	mu       sync.Mutex
	requests []*coltracepb.ExportTraceServiceRequest
}

func (s *mockTraceServer) Export(ctx context.Context, req *coltracepb.ExportTraceServiceRequest) (*coltracepb.ExportTraceServiceResponse, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.requests = append(s.requests, req)
	return &coltracepb.ExportTraceServiceResponse{}, nil
}

func (s *mockTraceServer) getRequests() []*coltracepb.ExportTraceServiceRequest {
	s.mu.Lock()
	defer s.mu.Unlock()
	copied := make([]*coltracepb.ExportTraceServiceRequest, len(s.requests))
	copy(copied, s.requests)
	return copied
}

func main() {
	ctx := context.Background()

	// 1. WithReconnectionPeriod creates option that configures reconnection period for OTLP trace client
	client := sample.NewTraceClient(sample.ExporterConfig{
		Endpoint:           "127.0.0.1:4317",
		Insecure:           true,
		ReconnectionPeriod: 2 * time.Second,
	})
	if client == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil client when configured with WithReconnectionPeriod\n")
		os.Exit(1)
	}

	// 2. WithReconnectionPeriod accepts various reconnection duration values
	durations := []time.Duration{
		100 * time.Millisecond,
		500 * time.Millisecond,
		1 * time.Second,
		5 * time.Second,
	}
	for _, d := range durations {
		opt := otlptracegrpc.WithReconnectionPeriod(d)
		if opt == nil {
			fmt.Fprintf(os.Stderr, "expected non-nil Option from WithReconnectionPeriod(%v)\n", d)
			os.Exit(1)
		}
		c := otlptracegrpc.NewClient(opt, otlptracegrpc.WithEndpoint("127.0.0.1:4317"), otlptracegrpc.WithInsecure())
		if c == nil {
			fmt.Fprintf(os.Stderr, "expected non-nil client with reconnection period %v\n", d)
			os.Exit(1)
		}
	}

	// Set up local in-memory TCP listener on ephemeral port for offline verification
	lis, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to bind local tcp listener: %v\n", err)
		os.Exit(1)
	}
	srv := grpc.NewServer()
	mockServer := &mockTraceServer{}
	coltracepb.RegisterTraceServiceServer(srv, mockServer)

	go func() {
		_ = srv.Serve(lis)
	}()
	defer srv.Stop()

	endpoint := lis.Addr().String()

	// 3. WithReconnectionPeriod with local gRPC server exports trace spans successfully
	exp, err := sample.NewExporter(ctx, sample.ExporterConfig{
		Endpoint:           endpoint,
		Insecure:           true,
		ReconnectionPeriod: 500 * time.Millisecond,
	})
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create exporter with WithReconnectionPeriod: %v\n", err)
		os.Exit(1)
	}

	tp, err := sample.NewTracerProvider(ctx, exp, "reconnection-contract-test")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create TracerProvider: %v\n", err)
		os.Exit(1)
	}

	// Emit span
	spanName := "reconnection-span-operation"
	_, span := sample.EmitSampleSpan(ctx, tp, "reconnection-tracer", spanName,
		attribute.String("app.component", "grpc-trace-exporter"),
		attribute.Int("reconnection.ms", 500),
	)
	spanCtx := span.SpanContext()
	wantTraceID := spanCtx.TraceID()
	wantSpanID := spanCtx.SpanID()

	if err := tp.ForceFlush(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "failed to flush tracer provider: %v\n", err)
		os.Exit(1)
	}

	// 4. Exported spans over connection configured with WithReconnectionPeriod preserve trace structure and attributes
	reqs := mockServer.getRequests()
	if len(reqs) == 0 {
		fmt.Fprintf(os.Stderr, "expected at least one gRPC export request, got none\n")
		os.Exit(1)
	}

	var foundSpan *tracepb.Span
	for _, req := range reqs {
		for _, rs := range req.GetResourceSpans() {
			for _, ss := range rs.GetScopeSpans() {
				for _, s := range ss.GetSpans() {
					if s.GetName() == spanName {
						foundSpan = s
						break
					}
				}
			}
		}
	}
	if foundSpan == nil {
		fmt.Fprintf(os.Stderr, "expected span %q not found in received gRPC export requests\n", spanName)
		os.Exit(1)
	}
	if [16]byte(foundSpan.GetTraceId()) != wantTraceID {
		fmt.Fprintf(os.Stderr, "trace ID mismatch: got %x, want %x\n", foundSpan.GetTraceId(), wantTraceID)
		os.Exit(1)
	}
	if [8]byte(foundSpan.GetSpanId()) != wantSpanID {
		fmt.Fprintf(os.Stderr, "span ID mismatch: got %x, want %x\n", foundSpan.GetSpanId(), wantSpanID)
		os.Exit(1)
	}

	attrMap := make(map[string]any)
	for _, kv := range foundSpan.GetAttributes() {
		if kv.GetValue().GetStringValue() != "" {
			attrMap[kv.GetKey()] = kv.GetValue().GetStringValue()
		} else if kv.GetValue().GetIntValue() != 0 {
			attrMap[kv.GetKey()] = kv.GetValue().GetIntValue()
		}
	}
	if gotVal := attrMap["app.component"]; gotVal != "grpc-trace-exporter" {
		fmt.Fprintf(os.Stderr, "span attribute app.component mismatch: got %v, want grpc-trace-exporter\n", gotVal)
		os.Exit(1)
	}
	if gotVal := attrMap["reconnection.ms"]; gotVal != int64(500) {
		fmt.Fprintf(os.Stderr, "span attribute reconnection.ms mismatch: got %v, want 500\n", gotVal)
		os.Exit(1)
	}

	// 5. Exporter and tracer provider shutdown flushes pending spans cleanly
	if err := tp.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "TracerProvider shutdown failed: %v\n", err)
		os.Exit(1)
	}
	if err := exp.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "Exporter shutdown failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println("All WithReconnectionPeriod contract assertions passed.")
}