github.com/google/uuid v1.6.0: generate and parse UUIDv4

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: generate and parse UUIDv4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/google/uuid@v1.6.0
Demonstrate these symbols/APIs:
  - NewRandom
  - Parse
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@11.8.0
  - runtime: node@24.13.1

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:de1727b573889e4c2614b92ff99dc63ce5e6f52b4e3d1a095e53ea5a5a4ee9d9","contract":["generate_random_uuid_v4","parse_valid_uuid_string","reject_invalid_uuid_string"],"goal":"generate and parse UUIDv4","kind":"HOW","packages":["pkg:golang/github.com/google/uuid@v1.6.0"],"schemaVersion":1,"symbols":["NewRandom","Parse"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","ecosystem":"golang","language":"go","os":"windows","osVersionBucket":"11","packageManager":"go","packageManagerVersion":"1.26.5","runtime":"go","runtimeVersion":"1.26.5","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/google/uuid@v1.6.0"],"schemaVersion":1,"symbols":["NewRandom","Parse"],"verifierAdapter":"golang@1"}

module contract

go 1.26.5

require github.com/google/uuid v1.6.0

github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

package main

import (
	"fmt"

	"github.com/google/uuid"
)

// GenerateUUIDv4 generates a new random RFC 4122 version 4 UUID.
func GenerateUUIDv4() (uuid.UUID, error) {
	return uuid.NewRandom()
}

// ParseUUID parses a string into a UUID.
func ParseUUID(s string) (uuid.UUID, error) {
	return uuid.Parse(s)
}

func main() {
	id, err := GenerateUUIDv4()
	if err != nil {
		panic(err)
	}
	fmt.Printf("Generated UUID: %s\n", id.String())

	parsed, err := ParseUUID(id.String())
	if err != nil {
		panic(err)
	}
	fmt.Printf("Parsed UUID version: %d\n", parsed.Version())
}

{
  "schemaVersion": 1,
  "goal": "generate and parse UUIDv4",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/google/uuid@v1.6.0"
  ],
  "symbols": [
    "NewRandom",
    "Parse"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@11.8.0",
    "runtime": "node@24.13.1"
  }
}

package test

import (
	"testing"

	"github.com/google/uuid"
)

func TestNewRandom(t *testing.T) {
	id, err := uuid.NewRandom()
	if err != nil {
		t.Fatalf("unexpected error generating random UUID: %v", err)
	}
	if id.Version() != 4 {
		t.Fatalf("expected UUID version 4, got %d", id.Version())
	}
	if id.Variant() != uuid.RFC4122 {
		t.Fatalf("expected RFC4122 variant, got %v", id.Variant())
	}
	if id.String() == "" {
		t.Fatal("expected non-empty UUID string")
	}
}

func TestParseValidUUID(t *testing.T) {
	raw := "6ba7b810-9dad-11d1-80b4-00c04fd430c8"
	parsed, err := uuid.Parse(raw)
	if err != nil {
		t.Fatalf("unexpected error parsing valid UUID: %v", err)
	}
	if parsed.String() != raw {
		t.Fatalf("expected %s, got %s", raw, parsed.String())
	}
	if parsed.Version() != 1 {
		t.Fatalf("expected version 1, got %d", parsed.Version())
	}
}

func TestParseInvalidUUID(t *testing.T) {
	invalid := "invalid-uuid-format"
	_, err := uuid.Parse(invalid)
	if err == nil {
		t.Fatal("expected error parsing invalid UUID, got nil")
	}
}