golang.org/x/mod v0.1.0

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/golang.org/x/mod@v0.1.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/mod@v0.1.0

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:c4a6bfca055c667a66e87a9b5e879d912a4d4344d8bc5e7ab00d5331fe81eddb","contract":["module.Check returns nil for a valid module path and semantic version","module.Check returns nil for major version \u003e= 2 when path includes matching /vN suffix","module.Check returns an error when major version \u003e= 2 lacks matching /vN path suffix","module.EscapePath and module.UnescapePath round-trip uppercase characters in module paths","module.Sort sorts module.Version slices by path and semantic version","semver.Canonical normalizes valid semantic versions and strips build metadata","semver.Compare orders semantic versions and treats build metadata as equal"],"goal":"verify pkg:golang/golang.org/x/mod@v0.1.0","kind":"HOW","packages":["pkg:golang/golang.org/x/mod@v0.1.0"],"schemaVersion":1},"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/golang.org/x/mod@v0.1.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/mod@v0.1.0","verifierAdapter":"golang@1"}

module example.com/sample

go 1.21

require golang.org/x/mod v0.1.0

golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/mod v0.1.0 h1:sfUMP1Gu8qASkorDVjnMuvgJzwFbTZSeXFiGBYAVdl4=
golang.org/x/mod v0.1.0/go.mod h1:0QHyrYULN0/3qlju5TqG8bIK38QM8yzMo5ekMj3DlcY=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/mod@v0.1.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/mod@v0.1.0"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/mod/module"
	"golang.org/x/mod/semver"
)

func fail(msg string) {
	fmt.Fprintln(os.Stderr, msg)
	os.Exit(1)
}

func main() {
	// 1. module.Check validates module path and semantic version pairs
	if err := module.Check("example.com/pkg", "v1.2.3"); err != nil {
		fail(fmt.Sprintf("expected nil for v1.2.3, got %v", err))
	}
	if err := module.Check("example.com/pkg/v2", "v2.0.0"); err != nil {
		fail(fmt.Sprintf("expected nil for /v2 with v2.0.0, got %v", err))
	}
	if err := module.Check("example.com/pkg", "v2.0.0"); err == nil {
		fail("expected error when major version >= 2 lacks matching /v2 path suffix, got nil")
	}

	// 2. module.EscapePath and module.UnescapePath round-trip uppercase characters
	escaped, err := module.EscapePath("example.com/MyPkg")
	if err != nil || escaped != "example.com/!my!pkg" {
		fail(fmt.Sprintf("unexpected EscapePath result: %q, %v", escaped, err))
	}
	unescaped, err := module.UnescapePath(escaped)
	if err != nil || unescaped != "example.com/MyPkg" {
		fail(fmt.Sprintf("unexpected UnescapePath result: %q, %v", unescaped, err))
	}

	// 3. module.Sort sorts module.Version slices by path and semantic version
	versions := []module.Version{
		{Path: "example.com/b", Version: "v1.0.0"},
		{Path: "example.com/a", Version: "v1.10.0"},
		{Path: "example.com/a", Version: "v1.2.0"},
	}
	module.Sort(versions)
	if versions[0].Path != "example.com/a" || versions[0].Version != "v1.2.0" ||
		versions[1].Version != "v1.10.0" || versions[2].Path != "example.com/b" {
		fail(fmt.Sprintf("unexpected module.Sort order: %+v", versions))
	}

	// 4. semver.Canonical and semver.Compare normalize and order semantic versions
	if got := semver.Canonical("v1.2.3+build1"); got != "v1.2.3" {
		fail(fmt.Sprintf("expected Canonical v1.2.3, got %q", got))
	}
	if cmp := semver.Compare("v1.2.0", "v1.10.0"); cmp >= 0 {
		fail(fmt.Sprintf("expected v1.2.0 < v1.10.0, got %d", cmp))
	}
	if cmp := semver.Compare("v1.2.3+meta1", "v1.2.3+meta2"); cmp != 0 {
		fail(fmt.Sprintf("expected build metadata to compare equal, got %d", cmp))
	}
}