golang.org/x/mod v0.24.0: validate, escape, and sort Go module paths and versions with module

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: validate, escape, and sort Go module paths and versions with module
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/mod@v0.24.0
Demonstrate these symbols/APIs:
  - golang.org/x/mod/module.Check
  - golang.org/x/mod/module.CheckPath
  - golang.org/x/mod/module.EscapePath
  - golang.org/x/mod/module.Sort
  - golang.org/x/mod/module.UnescapePath

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:sha256:1741a67e0b1e76cee6bc588843bcb9e4da896e9e9b9fd0a2788f65ebbc2278d3","contract":["module.CheckPath accepts valid module paths and rejects paths with invalid characters or leading slashes","module.Check validates that both module path and semantic version string are well-formed","module.Check rejects module versions missing the required v prefix","module.EscapePath replaces uppercase ASCII characters with exclamation marks followed by lowercase characters","module.UnescapePath restores escaped module paths back to their original uppercase characters","module.Sort sorts a slice of module versions primarily by path and secondarily by semantic version order"],"goal":"validate, escape, and sort Go module paths and versions with module","kind":"HOW","packages":["pkg:golang/golang.org/x/mod@v0.24.0"],"schemaVersion":1,"symbols":["golang.org/x/mod/module.Check","golang.org/x/mod/module.CheckPath","golang.org/x/mod/module.EscapePath","golang.org/x/mod/module.Sort","golang.org/x/mod/module.UnescapePath"]},"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@v0.24.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/mod@v0.24.0","symbols":["golang.org/x/mod/module.Check","golang.org/x/mod/module.CheckPath","golang.org/x/mod/module.EscapePath","golang.org/x/mod/module.Sort","golang.org/x/mod/module.UnescapePath"],"verifierAdapter":"golang@1"}

module sample-golang-mod

go 1.23.0

require golang.org/x/mod v0.24.0

golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww=

package main

import (
	"fmt"

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

func main() {
	path := "example.com/user/repo"
	if err := module.CheckPath(path); err != nil {
		fmt.Printf("invalid module path: %v\n", err)
		return
	}
	fmt.Printf("valid module path: %s\n", path)

	ver := "v1.2.0"
	if err := module.Check(path, ver); err != nil {
		fmt.Printf("invalid module version: %v\n", err)
		return
	}
	fmt.Printf("valid module: %s@%s\n", path, ver)

	caseSensitivePath := "github.com/Azure/azure-sdk-for-go"
	escaped, err := module.EscapePath(caseSensitivePath)
	if err != nil {
		fmt.Printf("escape path error: %v\n", err)
		return
	}
	fmt.Printf("escaped path: %s\n", escaped)

	unescaped, err := module.UnescapePath(escaped)
	if err != nil {
		fmt.Printf("unescape path error: %v\n", err)
		return
	}
	fmt.Printf("unescaped path: %s\n", unescaped)

	modules := []module.Version{
		{Path: "example.com/b", Version: "v1.1.0"},
		{Path: "example.com/a", Version: "v1.2.0"},
		{Path: "example.com/a", Version: "v1.0.0"},
	}
	module.Sort(modules)
	fmt.Println("Sorted modules:")
	for _, m := range modules {
		fmt.Printf("  %s@%s\n", m.Path, m.Version)
	}
}

{
  "schemaVersion": 1,
  "goal": "validate, escape, and sort Go module paths and versions with module",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/mod@v0.24.0"
  ],
  "symbols": [
    "golang.org/x/mod/module.Check",
    "golang.org/x/mod/module.CheckPath",
    "golang.org/x/mod/module.EscapePath",
    "golang.org/x/mod/module.Sort",
    "golang.org/x/mod/module.UnescapePath"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: module.CheckPath accepts valid module paths and rejects paths with invalid characters or leading slashes
	{
		validPaths := []string{
			"example.com/pkg",
			"golang.org/x/mod",
			"github.com/user/project",
		}
		for _, p := range validPaths {
			if err := module.CheckPath(p); err != nil {
				fmt.Fprintf(os.Stderr, "FAIL: CheckPath rejected valid path %q: %v\n", p, err)
				os.Exit(1)
			}
		}

		invalidPaths := []string{
			"/leading/slash",
			"trailing/slash/",
			"",
			"-invalid/start",
		}
		for _, p := range invalidPaths {
			if err := module.CheckPath(p); err == nil {
				fmt.Fprintf(os.Stderr, "FAIL: CheckPath accepted invalid path %q\n", p)
				os.Exit(1)
			}
		}
	}

	// Assertion 2: module.Check validates that both module path and semantic version string are well-formed
	{
		if err := module.Check("example.com/my/mod", "v1.2.3"); err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: Check rejected valid module and version: %v\n", err)
			os.Exit(1)
		}
	}

	// Assertion 3: module.Check rejects module versions missing the required v prefix
	{
		if err := module.Check("example.com/my/mod", "1.2.3"); err == nil {
			fmt.Fprintf(os.Stderr, "FAIL: Check accepted version without 'v' prefix\n")
			os.Exit(1)
		}
	}

	// Assertion 4: module.EscapePath replaces uppercase ASCII characters with exclamation marks followed by lowercase characters
	{
		escaped, err := module.EscapePath("github.com/Azure/azure-sdk")
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: EscapePath returned error: %v\n", err)
			os.Exit(1)
		}
		if escaped != "github.com/!azure/azure-sdk" {
			fmt.Fprintf(os.Stderr, "FAIL: EscapePath produced %q, expected 'github.com/!azure/azure-sdk'\n", escaped)
			os.Exit(1)
		}
	}

	// Assertion 5: module.UnescapePath restores escaped module paths back to their original uppercase characters
	{
		unescaped, err := module.UnescapePath("github.com/!azure/azure-sdk")
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: UnescapePath returned error: %v\n", err)
			os.Exit(1)
		}
		if unescaped != "github.com/Azure/azure-sdk" {
			fmt.Fprintf(os.Stderr, "FAIL: UnescapePath produced %q, expected 'github.com/Azure/azure-sdk'\n", unescaped)
			os.Exit(1)
		}
	}

	// Assertion 6: module.Sort sorts a slice of module versions primarily by path and secondarily by semantic version order
	{
		mods := []module.Version{
			{Path: "example.com/z", Version: "v1.0.0"},
			{Path: "example.com/a", Version: "v1.5.0"},
			{Path: "example.com/a", Version: "v1.1.0"},
			{Path: "example.com/a", Version: "v1.2.0-beta.1"},
		}
		module.Sort(mods)

		expected := []module.Version{
			{Path: "example.com/a", Version: "v1.1.0"},
			{Path: "example.com/a", Version: "v1.2.0-beta.1"},
			{Path: "example.com/a", Version: "v1.5.0"},
			{Path: "example.com/z", Version: "v1.0.0"},
		}

		if len(mods) != len(expected) {
			fmt.Fprintf(os.Stderr, "FAIL: sorted slice length mismatch\n")
			os.Exit(1)
		}

		for i := range mods {
			if mods[i] != expected[i] {
				fmt.Fprintf(os.Stderr, "FAIL: at index %d, got %+v, expected %+v\n", i, mods[i], expected[i])
				os.Exit(1)
			}
		}
	}

	fmt.Println("PASS: module contract passed")
}