go.opentelemetry.io/otel/trace v1.24.0: TraceIDFromHex

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 TraceIDFromHex in pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0
Demonstrate these symbols/APIs:
  - TraceIDFromHex

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:sha256:6b5a0bb32016390cd276c624ef69cb22c55c669b0854a3b35450ff34b6e0c2a0","contract":["TraceIDFromHex parses a valid 32-character lowercase hex string into a valid TraceID","TraceIDFromHex round-trips correctly with TraceID.String","TraceIDFromHex rejects an all-zero hex string with an error","TraceIDFromHex rejects hex strings not matching length 32","TraceIDFromHex rejects hex strings with uppercase or non-hex characters"],"goal":"verify TraceIDFromHex in pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0"],"schemaVersion":1,"symbols":["TraceIDFromHex"]},"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@v1.24.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0","symbols":["TraceIDFromHex"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.opentelemetry.io/otel/trace v1.24.0

require go.opentelemetry.io/otel v1.24.0 // 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 v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
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 v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
go.opentelemetry.io/otel v1.24.0 h1:0LAOdjNmQeSTzGBzduGe/rU4tZhMwL5rWgtp9Ku5Jfo=
go.opentelemetry.io/otel v1.24.0/go.mod h1:W7b9Ozg4nkF5tWI5zsXkaKKDjdVjpD4oAt9Qi/MArHo=
go.opentelemetry.io/otel/trace v1.24.0 h1:CsKnnL4dUAr/0llH9FKuc698G04IrpWV0MQA/Y1YELI=
go.opentelemetry.io/otel/trace v1.24.0/go.mod h1:HPc3Xr/cOApsBI154IU0OI0HJexz+aw5uPdbs3UCjNU=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

{
  "schemaVersion": 1,
  "goal": "verify TraceIDFromHex in pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/trace@v1.24.0"
  ],
  "symbols": [
    "TraceIDFromHex"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: TraceIDFromHex parses a valid 32-character lowercase hex string into a valid TraceID
	validHex := "4bf92f3577b34da6a3ce929d0e0e4736"
	tid, err := trace.TraceIDFromHex(validHex)
	if err != nil {
		fmt.Fprintf(os.Stderr, "expected nil error for valid hex %s, got: %v\n", validHex, err)
		os.Exit(1)
	}
	if !tid.IsValid() {
		fmt.Fprintf(os.Stderr, "expected tid.IsValid() to be true for %s\n", validHex)
		os.Exit(1)
	}

	// Assertion 2: TraceIDFromHex round-trips correctly with TraceID.String
	if str := tid.String(); str != validHex {
		fmt.Fprintf(os.Stderr, "expected round-trip string %q, got %q\n", validHex, str)
		os.Exit(1)
	}

	// Assertion 3: TraceIDFromHex rejects an all-zero hex string with an error
	zeroHex := "00000000000000000000000000000000"
	zeroTid, zeroErr := trace.TraceIDFromHex(zeroHex)
	if zeroErr == nil {
		fmt.Fprintf(os.Stderr, "expected error for all-zero hex string, got nil\n")
		os.Exit(1)
	}
	if zeroTid.IsValid() {
		fmt.Fprintf(os.Stderr, "expected all-zero TraceID to be invalid\n")
		os.Exit(1)
	}

	// Assertion 4: TraceIDFromHex rejects hex strings not matching length 32
	shortHex := "4bf92f3577b34da6"
	if _, err := trace.TraceIDFromHex(shortHex); err == nil {
		fmt.Fprintf(os.Stderr, "expected error for short hex string %s, got nil\n", shortHex)
		os.Exit(1)
	}
	longHex := "4bf92f3577b34da6a3ce929d0e0e4736ff"
	if _, err := trace.TraceIDFromHex(longHex); err == nil {
		fmt.Fprintf(os.Stderr, "expected error for long hex string %s, got nil\n", longHex)
		os.Exit(1)
	}

	// Assertion 5: TraceIDFromHex rejects hex strings with uppercase or non-hex characters
	upperHex := "4BF92F3577B34DA6A3CE929D0E0E4736"
	if _, err := trace.TraceIDFromHex(upperHex); err == nil {
		fmt.Fprintf(os.Stderr, "expected error for uppercase hex string, got nil\n")
		os.Exit(1)
	}
	invalidChars := "4bf92f3577b34da6a3ce929d0e0e473g"
	if _, err := trace.TraceIDFromHex(invalidChars); err == nil {
		fmt.Fprintf(os.Stderr, "expected error for invalid hex character, got nil\n")
		os.Exit(1)
	}

	// Helper verification using sample package
	parsed, err := sample.ParseTraceID(validHex)
	if err != nil || parsed != tid {
		fmt.Fprintf(os.Stderr, "sample.ParseTraceID mismatch\n")
		os.Exit(1)
	}

	mustParsed := sample.MustTraceID(validHex)
	if mustParsed != tid {
		fmt.Fprintf(os.Stderr, "sample.MustTraceID mismatch\n")
		os.Exit(1)
	}

	fmt.Println("PASS")
}

package sample

import (
	"fmt"

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

// ParseTraceID parses a 32-character hexadecimal string into an OpenTelemetry TraceID.
// It returns an error if the hex string is invalid, not 32 characters, contains uppercase characters,
// or consists of all zeros.
func ParseTraceID(hexID string) (trace.TraceID, error) {
	tid, err := trace.TraceIDFromHex(hexID)
	if err != nil {
		return trace.TraceID{}, fmt.Errorf("failed to parse trace ID: %w", err)
	}
	return tid, nil
}

// MustTraceID parses a hex string and panics if parsing fails.
func MustTraceID(hexID string) trace.TraceID {
	tid, err := ParseTraceID(hexID)
	if err != nil {
		panic(err)
	}
	return tid
}