github.com/google/uuid v1.6.0: NewString, Validate, Parse

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 pkg:golang/github.com/google/uuid@v1.6.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/google/uuid@v1.6.0
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:sha256:124a787765ec612d66b644cb24baa9527c039ab32673753490f02f3e9ff7ce11","contract":["uuid.NewString generates a valid 36-character UUID string","uuid.Validate validates correct UUID strings and rejects invalid format","uuid.Parse parses UUID strings into UUID values with Version 4 and RFC4122 variant","uuid.FromBytes converts a 16-byte slice to a UUID and rejects invalid lengths","uuid.NewRandom returns a random UUID of Version 4"],"goal":"verify pkg:golang/github.com/google/uuid@v1.6.0","kind":"HOW","packages":["pkg:golang/github.com/google/uuid@v1.6.0"],"schemaVersion":1,"symbols":["github.com/google/uuid.NewString","github.com/google/uuid.Validate","github.com/google/uuid.Parse","github.com/google/uuid.FromBytes","github.com/google/uuid.NewRandom"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","ecosystem":"golang","os":"windows","osVersionBucket":"11","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/google/uuid@v1.6.0"],"schemaVersion":1,"symbols":["github.com/google/uuid.NewString","github.com/google/uuid.Validate","github.com/google/uuid.Parse","github.com/google/uuid.FromBytes","github.com/google/uuid.NewRandom"],"verifierAdapter":"golang@1"}

module sample

go 1.22.0

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"
	"log"

	"github.com/google/uuid"
)

// GenerateRandomUUIDString generates a new Version 4 UUID string.
func GenerateRandomUUIDString() string {
	return uuid.NewString()
}

// ValidateUUIDString checks if a string is a valid UUID representation.
func ValidateUUIDString(s string) error {
	return uuid.Validate(s)
}

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

func main() {
	idStr := GenerateRandomUUIDString()
	fmt.Printf("Generated UUID: %s\n", idStr)

	if err := ValidateUUIDString(idStr); err != nil {
		log.Fatalf("Validation failed: %v\n", err)
	}
	fmt.Println("UUID validated successfully.")

	parsed, err := ParseUUIDString(idStr)
	if err != nil {
		log.Fatalf("Parsing failed: %v\n", err)
	}
	fmt.Printf("Parsed UUID version: %d, variant: %d\n", parsed.Version(), parsed.Variant())
}

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

package main

import (
	"bytes"
	"fmt"
	"os"

	"github.com/google/uuid"
)

func main() {
	// Assertion 1: uuid.NewString generates valid UUID string
	str1 := uuid.NewString()
	str2 := uuid.NewString()
	if len(str1) != 36 {
		fmt.Fprintf(os.Stderr, "FAIL: expected UUID string length 36, got %d\n", len(str1))
		os.Exit(1)
	}
	if str1 == str2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected unique UUID strings, got duplicate\n")
		os.Exit(1)
	}

	// Assertion 2: uuid.Validate validates correct and incorrect UUID strings
	if err := uuid.Validate(str1); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.Validate failed on valid UUID %q: %v\n", str1, err)
		os.Exit(1)
	}
	if err := uuid.Validate("not-a-valid-uuid"); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.Validate expected error for invalid UUID, got nil\n")
		os.Exit(1)
	}

	// Assertion 3: uuid.Parse parses UUID and inspects version and variant
	parsed, err := uuid.Parse(str1)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.Parse failed on valid UUID string: %v\n", err)
		os.Exit(1)
	}
	if parsed == uuid.Nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.Parse returned Nil UUID\n")
		os.Exit(1)
	}
	if parsed.Version() != 4 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Version 4, got %v\n", parsed.Version())
		os.Exit(1)
	}
	if parsed.Variant() != uuid.RFC4122 {
		fmt.Fprintf(os.Stderr, "FAIL: expected RFC4122 variant, got %v\n", parsed.Variant())
		os.Exit(1)
	}
	if parsed.String() != str1 {
		fmt.Fprintf(os.Stderr, "FAIL: round-trip mismatch: got %q, want %q\n", parsed.String(), str1)
		os.Exit(1)
	}

	// Assertion 4: uuid.FromBytes creates UUID from byte slice
	rawBytes := []byte{
		0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
		0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10,
	}
	fromBytesUUID, err := uuid.FromBytes(rawBytes)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.FromBytes failed: %v\n", err)
		os.Exit(1)
	}
	if !bytes.Equal(fromBytesUUID[:], rawBytes) {
		fmt.Fprintf(os.Stderr, "FAIL: bytes mismatch after FromBytes\n")
		os.Exit(1)
	}
	_, errInvalidBytes := uuid.FromBytes([]byte{0x01, 0x02})
	if errInvalidBytes == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error from FromBytes with short slice, got nil\n")
		os.Exit(1)
	}

	// Assertion 5: uuid.NewRandom returns random UUID v4
	randUUID, err := uuid.NewRandom()
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.NewRandom returned error: %v\n", err)
		os.Exit(1)
	}
	if randUUID.Version() != 4 {
		fmt.Fprintf(os.Stderr, "FAIL: uuid.NewRandom expected Version 4, got %v\n", randUUID.Version())
		os.Exit(1)
	}

	fmt.Println("PASS: all contract assertions passed for pkg:golang/github.com/google/uuid@v1.6.0")
}