go.opentelemetry.io/otel v1.37.0: attribute.NewSet

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/attribute.NewSet in pkg:golang/go.opentelemetry.io/otel@v1.37.0
Kind: HOW

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

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:sha256:9062b47299bc900a500d41073134f7d3b6184c4a6fe845320f1a2c327d3e6569","contract":["attribute.NewSet creates an empty Set when called with no arguments.","attribute.NewSet constructs a Set containing the provided KeyValues.","attribute.NewSet deduplicates keys using last-value-wins semantics.","attribute.NewSet sorts attributes by key in ToSlice output.","attribute.NewSet produces Sets that support Equals and Equivalent comparison."],"goal":"verify go.opentelemetry.io/otel/attribute.NewSet in pkg:golang/go.opentelemetry.io/otel@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel@v1.37.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/attribute.NewSet"]},"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@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel@v1.37.0","symbols":["go.opentelemetry.io/otel/attribute.NewSet"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.opentelemetry.io/otel v1.37.0

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=
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 (
	"fmt"

	"go.opentelemetry.io/otel/attribute"
)

func main() {
	// Construct a Set using attribute.NewSet
	set := attribute.NewSet(
		attribute.String("service.name", "order-service"),
		attribute.Int("service.port", 8080),
		attribute.Bool("production", true),
	)

	fmt.Printf("Set length: %d\n", set.Len())

	if val, ok := set.Value("service.name"); ok {
		fmt.Printf("service.name: %s\n", val.AsString())
	}

	// Demonstrate last-value-wins deduplication
	dedupSet := attribute.NewSet(
		attribute.String("env", "staging"),
		attribute.String("env", "production"),
	)
	if val, ok := dedupSet.Value("env"); ok {
		fmt.Printf("env: %s\n", val.AsString())
	}
}

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

package main

import (
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
)

func main() {
	// Assertion 1: attribute.NewSet creates an empty Set when called with no arguments.
	emptySet := attribute.NewSet()
	if emptySet.Len() != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected empty set length 0, got %d\n", emptySet.Len())
		os.Exit(1)
	}
	if len(emptySet.ToSlice()) != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected empty slice for empty set\n")
		os.Exit(1)
	}
	if emptySet.HasValue(attribute.Key("nonexistent")) {
		fmt.Fprintf(os.Stderr, "FAIL: HasValue returned true on empty set\n")
		os.Exit(1)
	}

	// Assertion 2: attribute.NewSet constructs a Set containing the provided KeyValues.
	set := attribute.NewSet(
		attribute.String("service.name", "auth"),
		attribute.Int("service.port", 8080),
		attribute.Bool("debug", true),
	)
	if set.Len() != 3 {
		fmt.Fprintf(os.Stderr, "FAIL: expected set length 3, got %d\n", set.Len())
		os.Exit(1)
	}
	if !set.HasValue(attribute.Key("service.name")) {
		fmt.Fprintf(os.Stderr, "FAIL: expected HasValue('service.name') to be true\n")
		os.Exit(1)
	}
	if val, ok := set.Value(attribute.Key("service.name")); !ok || val.AsString() != "auth" {
		fmt.Fprintf(os.Stderr, "FAIL: expected service.name 'auth', got '%s' (ok=%v)\n", val.AsString(), ok)
		os.Exit(1)
	}
	if val, ok := set.Value(attribute.Key("service.port")); !ok || val.AsInt64() != 8080 {
		fmt.Fprintf(os.Stderr, "FAIL: expected service.port 8080, got %d (ok=%v)\n", val.AsInt64(), ok)
		os.Exit(1)
	}
	if val, ok := set.Value(attribute.Key("debug")); !ok || val.AsBool() != true {
		fmt.Fprintf(os.Stderr, "FAIL: expected debug true, got %v (ok=%v)\n", val.AsBool(), ok)
		os.Exit(1)
	}

	// Assertion 3: attribute.NewSet deduplicates keys using last-value-wins semantics.
	dedupSet := attribute.NewSet(
		attribute.String("key", "first"),
		attribute.String("other", "val"),
		attribute.String("key", "second"),
	)
	if dedupSet.Len() != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected dedup set length 2, got %d\n", dedupSet.Len())
		os.Exit(1)
	}
	if val, ok := dedupSet.Value(attribute.Key("key")); !ok || val.AsString() != "second" {
		fmt.Fprintf(os.Stderr, "FAIL: expected last-value-wins 'second', got '%s'\n", val.AsString())
		os.Exit(1)
	}

	// Assertion 4: attribute.NewSet sorts attributes by key in ToSlice output.
	sortedSet := attribute.NewSet(
		attribute.String("z", "last"),
		attribute.String("a", "first"),
		attribute.String("m", "middle"),
	)
	slice := sortedSet.ToSlice()
	if len(slice) != 3 {
		fmt.Fprintf(os.Stderr, "FAIL: expected slice length 3, got %d\n", len(slice))
		os.Exit(1)
	}
	if slice[0].Key != attribute.Key("a") || slice[1].Key != attribute.Key("m") || slice[2].Key != attribute.Key("z") {
		fmt.Fprintf(os.Stderr, "FAIL: expected sorted keys [a, m, z], got [%s, %s, %s]\n",
			slice[0].Key, slice[1].Key, slice[2].Key)
		os.Exit(1)
	}

	// Assertion 5: attribute.NewSet produces Sets that support Equals and Equivalent comparison.
	s1 := attribute.NewSet(attribute.String("k1", "v1"), attribute.Int("k2", 2))
	s2 := attribute.NewSet(attribute.Int("k2", 2), attribute.String("k1", "v1"))
	if !s1.Equals(&s2) {
		fmt.Fprintf(os.Stderr, "FAIL: expected s1.Equals(&s2) to be true\n")
		os.Exit(1)
	}
	if s1.Equivalent() != s2.Equivalent() {
		fmt.Fprintf(os.Stderr, "FAIL: expected s1.Equivalent() == s2.Equivalent()\n")
		os.Exit(1)
	}
	s3 := attribute.NewSet(attribute.String("k1", "different"))
	if s1.Equals(&s3) {
		fmt.Fprintf(os.Stderr, "FAIL: expected s1.Equals(&s3) to be false\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all attribute.NewSet contract assertions passed.")
}