github.com/google/uuid v1.1.1: NewSHA1

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 github.com/google/uuid.NewSHA1 in pkg:golang/github.com/google/uuid@v1.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/google/uuid@v1.1.1
Demonstrate these symbols/APIs:
  - github.com/google/uuid.NewSHA1

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:sha256:237c05cabae3d5487647b09231cf11ec7c432b81e819d52f140468b688f02eb9","contract":["uuid.NewSHA1(uuid.NameSpaceDNS, []byte(\"example.com\")) returns a Version 5 (SHA-1) RFC4122 UUID equal to cfbff0d1-9375-5685-968c-48ce8b15ae17","Calling uuid.NewSHA1 with the same namespace and data is deterministic and returns an identical UUID, while changing the namespace produces a distinct UUID"],"goal":"verify github.com/google/uuid.NewSHA1 in pkg:golang/github.com/google/uuid@v1.1.1","kind":"HOW","packages":["pkg:golang/github.com/google/uuid@v1.1.1"],"schemaVersion":1,"symbols":["github.com/google/uuid.NewSHA1"]},"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/github.com/google/uuid@v1.1.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/google/uuid@v1.1.1","symbols":["github.com/google/uuid.NewSHA1"],"verifierAdapter":"golang@1"}

module sample

go 1.21

require github.com/google/uuid v1.1.1

github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

{
  "schemaVersion": 1,
  "goal": "verify github.com/google/uuid.NewSHA1 in pkg:golang/github.com/google/uuid@v1.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/google/uuid@v1.1.1"
  ],
  "symbols": [
    "github.com/google/uuid.NewSHA1"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/google/uuid"
)

func main() {
	u1 := uuid.NewSHA1(uuid.NameSpaceDNS, []byte("example.com"))
	if u1.Version() != 5 {
		fmt.Fprintf(os.Stderr, "expected version 5, got %v\n", u1.Version())
		os.Exit(1)
	}
	if u1.Variant() != uuid.RFC4122 {
		fmt.Fprintf(os.Stderr, "expected RFC4122 variant, got %v\n", u1.Variant())
		os.Exit(1)
	}
	expected := "cfbff0d1-9375-5685-968c-48ce8b15ae17"
	if u1.String() != expected {
		fmt.Fprintf(os.Stderr, "expected %s, got %s\n", expected, u1.String())
		os.Exit(1)
	}

	u2 := uuid.NewSHA1(uuid.NameSpaceDNS, []byte("example.com"))
	if u1 != u2 {
		fmt.Fprintf(os.Stderr, "expected deterministic UUIDs, got %s and %s\n", u1, u2)
		os.Exit(1)
	}

	u3 := uuid.NewSHA1(uuid.NameSpaceURL, []byte("example.com"))
	if u1 == u3 {
		fmt.Fprintf(os.Stderr, "expected different namespace to produce different UUID\n")
		os.Exit(1)
	}
}