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

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.KeyValue 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.KeyValue

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:c226cd176f9f2cb0af3af0908c3f85beb2a9f44034f61db29f228f4233e39cd0","contract":["attribute.KeyValue stores a typed Key and Value, accessible via struct fields.","attribute.KeyValue.Valid returns false for a zero-value KeyValue and true for an initialized KeyValue.","attribute.KeyValue instances with identical keys and values compare equal with standard equality operator.","attribute.KeyValue pairs can be aggregated into an attribute.Set, providing key-based lookup and deduplication.","attribute.KeyValue supports various Value types including string, bool, int64, and float64."],"goal":"verify go.opentelemetry.io/otel/attribute.KeyValue 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.KeyValue"]},"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.KeyValue"],"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 KeyValue directly and via helper
	kvDirect := attribute.KeyValue{
		Key:   attribute.Key("service.name"),
		Value: attribute.StringValue("payment-service"),
	}
	kvHelper := attribute.Int64("service.port", 8080)

	fmt.Printf("Direct KeyValue: %s=%s (valid: %t)\n",
		kvDirect.Key, kvDirect.Value.AsString(), kvDirect.Valid())
	fmt.Printf("Helper KeyValue: %s=%d (valid: %t)\n",
		kvHelper.Key, kvHelper.Value.AsInt64(), kvHelper.Valid())

	// Build an attribute set using KeyValues
	set := attribute.NewSet(kvDirect, kvHelper)
	if val, ok := set.Value(kvDirect.Key); ok {
		fmt.Printf("Set lookup '%s': %s\n", kvDirect.Key, val.AsString())
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/attribute.KeyValue 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.KeyValue"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: attribute.KeyValue stores a typed Key and Value, accessible via struct fields.
	k := attribute.Key("custom.attribute")
	v := attribute.StringValue("custom.value")
	kv := attribute.KeyValue{Key: k, Value: v}

	if kv.Key != k {
		fmt.Fprintf(os.Stderr, "FAIL: expected Key '%s', got '%s'\n", k, kv.Key)
		os.Exit(1)
	}
	if kv.Value.Type() != attribute.STRING {
		fmt.Fprintf(os.Stderr, "FAIL: expected Value type STRING, got %v\n", kv.Value.Type())
		os.Exit(1)
	}
	if kv.Value.AsString() != "custom.value" {
		fmt.Fprintf(os.Stderr, "FAIL: expected Value AsString 'custom.value', got '%s'\n", kv.Value.AsString())
		os.Exit(1)
	}

	// Assertion 2: attribute.KeyValue.Valid returns false for a zero-value KeyValue and true for an initialized KeyValue.
	var zeroKV attribute.KeyValue
	if zeroKV.Valid() {
		fmt.Fprintf(os.Stderr, "FAIL: expected zero-value KeyValue.Valid() to be false\n")
		os.Exit(1)
	}
	if !kv.Valid() {
		fmt.Fprintf(os.Stderr, "FAIL: expected initialized KeyValue.Valid() to be true\n")
		os.Exit(1)
	}

	// Assertion 3: attribute.KeyValue instances with identical keys and values compare equal with standard equality operator.
	kvA1 := attribute.KeyValue{Key: attribute.Key("app.version"), Value: attribute.StringValue("1.0.0")}
	kvA2 := attribute.KeyValue{Key: attribute.Key("app.version"), Value: attribute.StringValue("1.0.0")}
	kvDiffKey := attribute.KeyValue{Key: attribute.Key("app.name"), Value: attribute.StringValue("1.0.0")}
	kvDiffVal := attribute.KeyValue{Key: attribute.Key("app.version"), Value: attribute.StringValue("2.0.0")}

	if kvA1 != kvA2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected identical KeyValue structs to compare equal\n")
		os.Exit(1)
	}
	if kvA1 == kvDiffKey {
		fmt.Fprintf(os.Stderr, "FAIL: expected KeyValues with different keys to not compare equal\n")
		os.Exit(1)
	}
	if kvA1 == kvDiffVal {
		fmt.Fprintf(os.Stderr, "FAIL: expected KeyValues with different values to not compare equal\n")
		os.Exit(1)
	}

	// Assertion 4: attribute.KeyValue pairs can be aggregated into an attribute.Set, providing key-based lookup and deduplication.
	kv1 := attribute.KeyValue{Key: attribute.Key("tag"), Value: attribute.StringValue("initial")}
	kv2 := attribute.KeyValue{Key: attribute.Key("env"), Value: attribute.StringValue("test")}
	kv1Override := attribute.KeyValue{Key: attribute.Key("tag"), Value: attribute.StringValue("updated")}

	set := attribute.NewSet(kv1, kv2, kv1Override)
	if set.Len() != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected set length 2 after deduplication, got %d\n", set.Len())
		os.Exit(1)
	}
	if val, ok := set.Value(attribute.Key("tag")); !ok || val.AsString() != "updated" {
		fmt.Fprintf(os.Stderr, "FAIL: expected 'tag' to be 'updated', got '%s' (ok=%v)\n", val.AsString(), ok)
		os.Exit(1)
	}
	if val, ok := set.Value(attribute.Key("env")); !ok || val.AsString() != "test" {
		fmt.Fprintf(os.Stderr, "FAIL: expected 'env' to be 'test', got '%s' (ok=%v)\n", val.AsString(), ok)
		os.Exit(1)
	}
	if _, ok := set.Value(attribute.Key("missing")); ok {
		fmt.Fprintf(os.Stderr, "FAIL: expected 'missing' key lookup to return false\n")
		os.Exit(1)
	}

	// Assertion 5: attribute.KeyValue supports various Value types including string, bool, int64, and float64.
	strKV := attribute.String("attr.string", "sample-text")
	boolKV := attribute.Bool("attr.bool", true)
	intKV := attribute.Int64("attr.int64", int64(123456))
	floatKV := attribute.Float64("attr.float64", 3.14159)

	if strKV.Value.Type() != attribute.STRING || strKV.Value.AsString() != "sample-text" {
		fmt.Fprintf(os.Stderr, "FAIL: string KeyValue mismatch\n")
		os.Exit(1)
	}
	if boolKV.Value.Type() != attribute.BOOL || !boolKV.Value.AsBool() {
		fmt.Fprintf(os.Stderr, "FAIL: bool KeyValue mismatch\n")
		os.Exit(1)
	}
	if intKV.Value.Type() != attribute.INT64 || intKV.Value.AsInt64() != int64(123456) {
		fmt.Fprintf(os.Stderr, "FAIL: int64 KeyValue mismatch\n")
		os.Exit(1)
	}
	if floatKV.Value.Type() != attribute.FLOAT64 || floatKV.Value.AsFloat64() != 3.14159 {
		fmt.Fprintf(os.Stderr, "FAIL: float64 KeyValue mismatch\n")
		os.Exit(1)
	}

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