github.com/rogpeppe/go-internal v1.3.0: 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 github.com/rogpeppe/go-internal/semver.Compare in pkg:golang/github.com/rogpeppe/go-internal@v1.3.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/rogpeppe/go-internal@v1.3.0
Demonstrate these symbols/APIs:
  - github.com/rogpeppe/go-internal/semver.Compare

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:b89469936a3fd82de95169d0af7721ba2ac9fca47354be0299c59a831e596b76","contract":["semver.Compare returns -1 when the first version is lower than the second.","semver.Compare returns 0 when two versions are equivalent.","semver.Compare returns 1 when the first version is higher than the second.","semver.Compare correctly orders prerelease versions lower than the associated release.","semver.Compare considers invalid semantic versions lower than any valid version."],"goal":"verify github.com/rogpeppe/go-internal/semver.Compare in pkg:golang/github.com/rogpeppe/go-internal@v1.3.0","kind":"HOW","packages":["pkg:golang/github.com/rogpeppe/go-internal@v1.3.0"],"schemaVersion":1,"symbols":["github.com/rogpeppe/go-internal/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/github.com/rogpeppe/go-internal@v1.3.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/rogpeppe/go-internal@v1.3.0","symbols":["github.com/rogpeppe/go-internal/semver.Compare"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/rogpeppe/go-internal v1.3.0

github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
github.com/rogpeppe/go-internal v1.3.0 h1:RR9dF3JtopPvtkroDZuVD7qquD0bnHlKSqaQhgwt8yk=
github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=

package main

import (
	"fmt"

	"github.com/rogpeppe/go-internal/semver"
)

func main() {
	v1 := "v1.2.0"
	v2 := "v1.3.0"
	cmp := semver.Compare(v1, v2)
	fmt.Printf("semver.Compare(%q, %q) = %d\n", v1, v2, cmp)

	v3 := "v1.3.0"
	cmp2 := semver.Compare(v2, v3)
	fmt.Printf("semver.Compare(%q, %q) = %d\n", v2, v3, cmp2)

	vPre := "v1.3.0-beta.1"
	cmp3 := semver.Compare(vPre, v2)
	fmt.Printf("semver.Compare(%q, %q) = %d\n", vPre, v2, cmp3)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/rogpeppe/go-internal/semver.Compare in pkg:golang/github.com/rogpeppe/go-internal@v1.3.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/rogpeppe/go-internal@v1.3.0"
  ],
  "symbols": [
    "github.com/rogpeppe/go-internal/semver.Compare"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/rogpeppe/go-internal/semver"
)

func main() {
	// Assertion 1: semver.Compare returns -1 when the first version is lower than the second.
	if res := semver.Compare("v1.0.0", "v2.0.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0, v2.0.0) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.1.0", "v1.2.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.1.0, v1.2.0) == -1, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 2: semver.Compare returns 0 when two versions are equivalent.
	if res := semver.Compare("v1.2.3", "v1.2.3"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.2.3, v1.2.3) == 0, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.2.3+build1", "v1.2.3+build2"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.2.3+build1, v1.2.3+build2) == 0, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 3: semver.Compare returns 1 when the first version is higher than the second.
	if res := semver.Compare("v2.0.0", "v1.0.0"); res != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v2.0.0, v1.0.0) == 1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.2.1", "v1.2.0"); res != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.2.1, v1.2.0) == 1, got %d\n", res)
		os.Exit(1)
	}

	// Assertion 4: semver.Compare correctly orders prerelease versions lower than the associated release.
	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)
	}

	// Assertion 5: semver.Compare considers invalid semantic versions lower than any valid version.
	if res := semver.Compare("invalid", "v1.0.0"); res != -1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(invalid, v1.0.0) == -1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("v1.0.0", "invalid"); res != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(v1.0.0, invalid) == 1, got %d\n", res)
		os.Exit(1)
	}
	if res := semver.Compare("invalid1", "invalid2"); res != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Compare(invalid1, invalid2) == 0, got %d\n", res)
		os.Exit(1)
	}

	fmt.Println("PASS: all semver.Compare contract assertions passed.")
}