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

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.STRING 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.STRING

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:sha256:32fedd3e18ee2961dabcb97be970104d13126c058c07e499f048c256fdcf7f9c","contract":["attribute.STRING is the Type constant representing string values and has string representation STRING.","attribute.StringValue creates a Value with Type equal to attribute.STRING.","attribute.String creates a KeyValue whose Value has Type attribute.STRING.","Value of Type attribute.STRING returns its underlying string through AsString and Emit.","Type switch discriminates attribute.STRING from other attribute types."],"goal":"verify go.opentelemetry.io/otel/attribute.STRING 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.STRING"]},"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.STRING"],"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() {
	// Demonstrate attribute.STRING type constant
	targetType := attribute.STRING
	fmt.Printf("Demonstrating attribute type: %s\n", targetType)

	// Create a StringValue and verify its type matches attribute.STRING
	val := attribute.StringValue("example-value")
	if val.Type() == attribute.STRING {
		fmt.Printf("StringValue has expected type STRING: %s\n", val.AsString())
	}

	// Create a KeyValue using attribute.String and inspect its Type
	kv := attribute.String("example.key", "attribute-data")
	if kv.Value.Type() == attribute.STRING {
		fmt.Printf("KeyValue '%s' carries STRING type with value: %s\n", kv.Key, kv.Value.Emit())
	}
}

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

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: attribute.STRING is the Type constant representing string values and has string representation STRING.
	if attribute.STRING.String() != "STRING" {
		fmt.Fprintf(os.Stderr, "FAIL: expected attribute.STRING.String() == 'STRING', got '%s'\n", attribute.STRING.String())
		os.Exit(1)
	}
	if attribute.STRING == attribute.INVALID || attribute.STRING == attribute.BOOL || attribute.STRING == attribute.INT64 || attribute.STRING == attribute.FLOAT64 || attribute.STRING == attribute.STRINGSLICE {
		fmt.Fprintf(os.Stderr, "FAIL: attribute.STRING conflicts with other types\n")
		os.Exit(1)
	}

	// Assertion 2: attribute.StringValue creates a Value with Type equal to attribute.STRING.
	val := attribute.StringValue("sample-payload")
	if val.Type() != attribute.STRING {
		fmt.Fprintf(os.Stderr, "FAIL: expected StringValue type to be attribute.STRING, got %v\n", val.Type())
		os.Exit(1)
	}

	// Assertion 3: attribute.String creates a KeyValue whose Value has Type attribute.STRING.
	kv := attribute.String("http.route", "/items")
	if kv.Value.Type() != attribute.STRING {
		fmt.Fprintf(os.Stderr, "FAIL: expected attribute.String Value.Type() to be attribute.STRING, got %v\n", kv.Value.Type())
		os.Exit(1)
	}
	key := attribute.Key("custom.id")
	kvFromKey := key.String("12345")
	if kvFromKey.Value.Type() != attribute.STRING {
		fmt.Fprintf(os.Stderr, "FAIL: expected Key.String Value.Type() to be attribute.STRING, got %v\n", kvFromKey.Value.Type())
		os.Exit(1)
	}

	// Assertion 4: Value of Type attribute.STRING returns its underlying string through AsString and Emit.
	if s := val.AsString(); s != "sample-payload" {
		fmt.Fprintf(os.Stderr, "FAIL: expected AsString 'sample-payload', got '%s'\n", s)
		os.Exit(1)
	}
	if e := val.Emit(); e != "sample-payload" {
		fmt.Fprintf(os.Stderr, "FAIL: expected Emit 'sample-payload', got '%s'\n", e)
		os.Exit(1)
	}

	// Assertion 5: Type switch discriminates attribute.STRING from other attribute types.
	classify := func(t attribute.Type) string {
		switch t {
		case attribute.STRING:
			return "matched_string"
		case attribute.BOOL:
			return "matched_bool"
		case attribute.INT64:
			return "matched_int64"
		default:
			return "matched_other"
		}
	}
	if classify(attribute.STRING) != "matched_string" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed to match attribute.STRING\n")
		os.Exit(1)
	}
	if classify(attribute.BOOL) != "matched_bool" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed on BOOL\n")
		os.Exit(1)
	}
	if classify(attribute.INT64) != "matched_int64" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed on INT64\n")
		os.Exit(1)
	}

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