go.opentelemetry.io/otel/trace v1.47.0: TraceID

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.TraceID in pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/trace.TraceID

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:ba01094bcbb2c977ad117ac478451205c7de0d9d46b7d6b9710615b516e8c102","contract":["TraceIDFromHex creates a valid TraceID from a 32-character hexadecimal string.","TraceIDFromHex returns an error for invalid length or invalid hexadecimal characters.","TraceID zero value is invalid and produces a 32-character zero string.","TraceID preserves raw byte array values and formats correctly via String.","TraceID MarshalJSON outputs a valid quoted JSON hex string.","TraceID integrates with SpanContext to identify traces."],"goal":"verify go.opentelemetry.io/otel/trace.TraceID in pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/trace.TraceID"]},"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@v1.47.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0","symbols":["go.opentelemetry.io/otel/trace.TraceID"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.opentelemetry.io/otel/trace v1.47.0

require (
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	go.opentelemetry.io/otel v1.47.0 // indirect
)

github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
go.opentelemetry.io/otel v1.47.0 h1:j7ALJ/zgkS7Z6aeJW09p8VC9804bC+PpeTfCD4XPnOM=
go.opentelemetry.io/otel v1.47.0/go.mod h1:8wS9O2qfXrYrzp6hIF/HOYJJf/wIhFPhR2xLuP+iXQU=
go.opentelemetry.io/otel/trace v1.47.0 h1:JOjX/Oci8K94QHddo+bbfya/Ai/nf6/dt9ZfrFNWSrM=
go.opentelemetry.io/otel/trace v1.47.0/go.mod h1:jNaSLa2PZEYFG6fRjJABAu+bw4FS08uDmPg28lTghu0=

package main

import (
	"encoding/json"
	"fmt"

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

func main() {
	// 1. Create a TraceID from hex string (32 hex characters)
	hexStr := "4bf92f3577b34da6a3ce929d0e0e4736"
	traceID, err := trace.TraceIDFromHex(hexStr)
	if err != nil {
		panic(err)
	}
	fmt.Printf("TraceID: %s, IsValid: %t\n", traceID.String(), traceID.IsValid())

	// 2. Create TraceID from raw byte array (16 bytes)
	raw := [16]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10}
	rawTraceID := trace.TraceID(raw)
	fmt.Printf("Raw TraceID: %s\n", rawTraceID.String())

	// 3. Marshal TraceID to JSON
	data, err := json.Marshal(traceID)
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON representation: %s\n", string(data))

	// 4. Integrate with SpanContext
	sc := trace.NewSpanContext(trace.SpanContextConfig{
		TraceID: traceID,
	})
	fmt.Printf("SpanContext TraceID: %s, HasTraceID: %t\n", sc.TraceID().String(), sc.HasTraceID())
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/trace.TraceID in pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/trace@v1.47.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/trace.TraceID"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: TraceIDFromHex creates a valid TraceID from a 32-character hexadecimal string.
	hexStr := "4bf92f3577b34da6a3ce929d0e0e4736"
	traceID, err := trace.TraceIDFromHex(hexStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: TraceIDFromHex returned error: %v\n", err)
		os.Exit(1)
	}
	if !traceID.IsValid() {
		fmt.Fprintf(os.Stderr, "FAIL: expected traceID to be valid\n")
		os.Exit(1)
	}
	if traceID.String() != hexStr {
		fmt.Fprintf(os.Stderr, "FAIL: expected String() to be '%s', got '%s'\n", hexStr, traceID.String())
		os.Exit(1)
	}

	// Assertion 2: TraceIDFromHex returns an error for invalid length or invalid hexadecimal characters.
	if _, err := trace.TraceIDFromHex("1234"); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error for short hex string\n")
		os.Exit(1)
	}
	if _, err := trace.TraceIDFromHex("4bf92f3577b34da6a3ce929d0e0e473678"); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error for long hex string\n")
		os.Exit(1)
	}
	if _, err := trace.TraceIDFromHex("4bf92f3577b34da6a3ce929d0e0e47zz"); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error for non-hex characters\n")
		os.Exit(1)
	}

	// Assertion 3: TraceID zero value is invalid and produces a 32-character zero string.
	var zero trace.TraceID
	if zero.IsValid() {
		fmt.Fprintf(os.Stderr, "FAIL: expected zero TraceID to be invalid\n")
		os.Exit(1)
	}
	if zero.String() != "00000000000000000000000000000000" {
		fmt.Fprintf(os.Stderr, "FAIL: expected zero TraceID string '00000000000000000000000000000000', got '%s'\n", zero.String())
		os.Exit(1)
	}

	// Assertion 4: TraceID preserves raw byte array values and formats correctly via String.
	raw := [16]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f}
	rawTraceID := trace.TraceID(raw)
	if !rawTraceID.IsValid() {
		fmt.Fprintf(os.Stderr, "FAIL: expected rawTraceID with non-zero bytes to be valid\n")
		os.Exit(1)
	}
	if rawTraceID.String() != "000102030405060708090a0b0c0d0e0f" {
		fmt.Fprintf(os.Stderr, "FAIL: expected String() to be '000102030405060708090a0b0c0d0e0f', got '%s'\n", rawTraceID.String())
		os.Exit(1)
	}
	if [16]byte(rawTraceID) != raw {
		fmt.Fprintf(os.Stderr, "FAIL: byte representation mismatch\n")
		os.Exit(1)
	}

	// Assertion 5: TraceID MarshalJSON outputs a valid quoted JSON hex string.
	jsonData, err := traceID.MarshalJSON()
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: MarshalJSON returned error: %v\n", err)
		os.Exit(1)
	}
	expectedJSON := fmt.Sprintf("%q", hexStr)
	if string(jsonData) != expectedJSON {
		fmt.Fprintf(os.Stderr, "FAIL: expected JSON %s, got %s\n", expectedJSON, string(jsonData))
		os.Exit(1)
	}

	// Assertion 6: TraceID integrates with SpanContext to identify traces.
	sc := trace.NewSpanContext(trace.SpanContextConfig{
		TraceID: traceID,
	})
	if !sc.HasTraceID() {
		fmt.Fprintf(os.Stderr, "FAIL: expected SpanContext to have TraceID\n")
		os.Exit(1)
	}
	if sc.TraceID() != traceID {
		fmt.Fprintf(os.Stderr, "FAIL: expected SpanContext TraceID '%s', got '%s'\n", traceID.String(), sc.TraceID().String())
		os.Exit(1)
	}

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