go.opentelemetry.io/otel/trace v1.37.0: WithSpanKind

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 go.opentelemetry.io/otel/trace.WithSpanKind in pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/trace.WithSpanKind

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:sha256:6327436b1a9be51e3fc2c201ab92d2c376ba8347091b4f3ea6881d41c4a6e911","contract":["trace.WithSpanKind sets SpanKind on SpanConfig via trace.NewSpanStartConfig","trace.WithSpanKind configures server, client, producer, consumer, and internal span kinds correctly","trace.WithSpanKind applies last-value-wins precedence when multiple WithSpanKind options are provided","trace.WithSpanKind configures span kind when starting a span with a Tracer"],"goal":"verify go.opentelemetry.io/otel/trace.WithSpanKind in pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/trace.WithSpanKind"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0","symbols":["go.opentelemetry.io/otel/trace.WithSpanKind"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.23.0

require go.opentelemetry.io/otel/trace v1.37.0

require go.opentelemetry.io/otel v1.37.0 // indirect

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/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
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 v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mxVK7z4=
go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/trace/noop"
)

func main() {
	opt := trace.WithSpanKind(trace.SpanKindServer)
	cfg := trace.NewSpanStartConfig(opt)
	fmt.Printf("SpanKind: %s (%d)\n", cfg.SpanKind().String(), cfg.SpanKind())

	tr := noop.NewTracerProvider().Tracer("example.com/demo")
	ctx, span := tr.Start(context.Background(), "handle-request", trace.WithSpanKind(trace.SpanKindServer))
	defer span.End()
	_ = ctx
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/trace.WithSpanKind in pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/trace@v1.37.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/trace.WithSpanKind"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/trace/noop"
)

func main() {
	// Assertion 1: trace.WithSpanKind sets SpanKind on SpanConfig via trace.NewSpanStartConfig
	cfgServer := trace.NewSpanStartConfig(trace.WithSpanKind(trace.SpanKindServer))
	if cfgServer.SpanKind() != trace.SpanKindServer {
		fmt.Fprintf(os.Stderr, "FAIL: expected SpanKindServer, got %v\n", cfgServer.SpanKind())
		os.Exit(1)
	}

	// Assertion 2: trace.WithSpanKind configures server, client, producer, consumer, and internal span kinds correctly
	kinds := []trace.SpanKind{
		trace.SpanKindInternal,
		trace.SpanKindServer,
		trace.SpanKindClient,
		trace.SpanKindProducer,
		trace.SpanKindConsumer,
	}
	for _, k := range kinds {
		cfg := trace.NewSpanStartConfig(trace.WithSpanKind(k))
		if cfg.SpanKind() != k {
			fmt.Fprintf(os.Stderr, "FAIL: expected %v, got %v\n", k, cfg.SpanKind())
			os.Exit(1)
		}
	}

	// Assertion 3: trace.WithSpanKind applies last-value-wins precedence when multiple WithSpanKind options are provided
	cfgOverride := trace.NewSpanStartConfig(
		trace.WithSpanKind(trace.SpanKindClient),
		trace.WithSpanKind(trace.SpanKindProducer),
	)
	if cfgOverride.SpanKind() != trace.SpanKindProducer {
		fmt.Fprintf(os.Stderr, "FAIL: expected SpanKindProducer from overwrite, got %v\n", cfgOverride.SpanKind())
		os.Exit(1)
	}

	// Assertion 4: trace.WithSpanKind configures span kind when starting a span with a Tracer
	tr := noop.NewTracerProvider().Tracer("example.com/test")
	ctx, span := tr.Start(context.Background(), "test-span", trace.WithSpanKind(trace.SpanKindClient))
	if span == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-nil span\n")
		os.Exit(1)
	}
	defer span.End()
	if ctx == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-nil ctx\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all trace.WithSpanKind contract assertions passed.")
}