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

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.MustParse 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.MustParse

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:sha256:19a848ebe6c02805f1a19e454ec4b8b45c107289e865c9d91041406198e2e747","contract":["uuid.MustParse parses canonical 36-character RFC 4122, URN, and braced UUID strings into identical 16-byte uuid.UUID values","uuid.MustParse panics when given an invalid UUID string"],"goal":"verify github.com/google/uuid.MustParse 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.MustParse"]},"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.MustParse"],"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.MustParse 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.MustParse"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/google/uuid"
)

func expectPanic(fn func()) (panicked bool) {
	defer func() {
		if r := recover(); r != nil {
			panicked = true
		}
	}()
	fn()
	return false
}

func main() {
	// 1. Standard canonical RFC 4122 UUID string parses without panic and round-trips via String().
	canonical := "6ba7b810-9dad-11d1-80b4-00c04fd430c8"
	u1 := uuid.MustParse(canonical)
	if u1.String() != canonical {
		fmt.Fprintf(os.Stderr, "expected %q, got %q\n", canonical, u1.String())
		os.Exit(1)
	}
	if u1.Version() != 1 || u1.Variant() != uuid.RFC4122 {
		fmt.Fprintf(os.Stderr, "unexpected version/variant: %v / %v\n", u1.Version(), u1.Variant())
		os.Exit(1)
	}

	// 2. URN and braced formats parse to the identical 16-byte UUID value.
	uURN := uuid.MustParse("urn:uuid:6ba7b810-9dad-11d1-80b4-00c04fd430c8")
	uBraced := uuid.MustParse("{6ba7b810-9dad-11d1-80b4-00c04fd430c8}")
	if uURN != u1 || uBraced != u1 {
		fmt.Fprintf(os.Stderr, "URN or braced UUID did not match canonical UUID\n")
		os.Exit(1)
	}

	// 3. Invalid UUID string causes MustParse to panic.
	if !expectPanic(func() {
		_ = uuid.MustParse("not-a-valid-uuid")
	}) {
		fmt.Fprintf(os.Stderr, "expected MustParse to panic on invalid input\n")
		os.Exit(1)
	}
}