golang.org/x/mod v0.18.0: semver.Compare

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 golang.org/x/mod/semver.Compare in pkg:golang/golang.org/x/mod@v0.18.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/mod@v0.18.0
Demonstrate these symbols/APIs:
  - golang.org/x/mod/semver.Compare
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:e70cfa67c5e972318cb6cc853a22f1ad0a0496a0f3cafc1aedd17654b04939f9","contract":["semver.Compare returns -1, 0, or 1 for standard semantic versions based on major, minor, and patch precedence","semver.Compare orders prerelease versions below the corresponding release version","semver.Compare ignores build metadata when evaluating version precedence","semver.Compare orders invalid semantic version strings before any valid semantic version"],"goal":"verify golang.org/x/mod/semver.Compare in pkg:golang/golang.org/x/mod@v0.18.0","kind":"HOW","packages":["pkg:golang/golang.org/x/mod@v0.18.0"],"schemaVersion":1,"symbols":["golang.org/x/mod/semver.Compare"]},"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@v0.18.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/mod@v0.18.0","symbols":["golang.org/x/mod/semver.Compare"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require golang.org/x/mod v0.18.0

golang.org/x/mod v0.18.0 h1:5+9lSbEzPSdWkH32vYPBwEpX8KwDbM52Ud9xBUvNlb0=
golang.org/x/mod v0.18.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=

package main

import (
	"fmt"

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

// CompareVersions compares two semantic versions using semver.Compare.
func CompareVersions(v1, v2 string) int {
	return semver.Compare(v1, v2)
}

func main() {
	v1 := "v1.2.3"
	v2 := "v1.2.4"
	v3 := "v1.2.3-alpha"
	v4 := "v1.2.3+build.1"

	fmt.Printf("Compare(%s, %s) = %d\n", v1, v2, CompareVersions(v1, v2))
	fmt.Printf("Compare(%s, %s) = %d\n", v3, v1, CompareVersions(v3, v1))
	fmt.Printf("Compare(%s, %s) = %d\n", v1, v4, CompareVersions(v1, v4))
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/mod/semver.Compare in pkg:golang/golang.org/x/mod@v0.18.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/mod@v0.18.0"
  ],
  "symbols": [
    "golang.org/x/mod/semver.Compare"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: semver.Compare returns -1, 0, or 1 for standard semantic versions based on major, minor, and patch precedence
	if res := semver.Compare("v1.2.3", "v1.2.4"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.2.3, v1.2.4) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v2.0.0", "v1.9.9"); res != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v2.0.0, v1.9.9) == 1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.5.0", "v1.5.0"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.5.0, v1.5.0) == 0, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 2: semver.Compare orders prerelease versions below the corresponding release version
	if res := semver.Compare("v1.0.0-alpha", "v1.0.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0-alpha, v1.0.0) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.0.0-alpha", "v1.0.0-beta"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0-alpha, v1.0.0-beta) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.0.0-alpha.1", "v1.0.0-alpha.2"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0-alpha.1, v1.0.0-alpha.2) == -1, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 3: semver.Compare ignores build metadata when evaluating version precedence
	if res := semver.Compare("v1.0.0+build1", "v1.0.0+build2"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0+build1, v1.0.0+build2) == 0, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.0.0-alpha+001", "v1.0.0-alpha+exp.sha.5114f85"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0-alpha+001, v1.0.0-alpha+exp.sha.5114f85) == 0, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 4: semver.Compare orders invalid semantic version strings before any valid semantic version
	if res := semver.Compare("invalid", "v0.0.1"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(invalid, v0.0.1) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("1.0.0", "v1.0.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(1.0.0, v1.0.0) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("", "v0.0.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare('', v0.0.0) == -1, got %d\n", res)
		os.Exit(1)
	}

	fmt.Println("PASS: golang.org/x/mod/semver.Compare contract verified")
}