github.com/Masterminds/semver/v3 v3.3.0: NewConstraint

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/Masterminds/semver/v3.NewConstraint in pkg:golang/github.com/Masterminds/semver/v3@v3.3.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/Masterminds/semver/v3@v3.3.0
Demonstrate these symbols/APIs:
  - github.com/Masterminds/semver/v3.NewConstraint

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:sha256:2702b236bb60e8aa843531df129cd3ca541213bdd69c53976e2afe8f2ecf958f","contract":["semver.NewConstraint parses valid constraint expressions including range and wildcard syntax","semver.NewConstraint rejects invalid constraint expressions with an error","semver.NewConstraint validates whether semantic versions satisfy range constraints","semver.NewConstraint validates versions and returns failure reasons when constraints are not met"],"goal":"verify github.com/Masterminds/semver/v3.NewConstraint in pkg:golang/github.com/Masterminds/semver/v3@v3.3.0","kind":"HOW","packages":["pkg:golang/github.com/Masterminds/semver/v3@v3.3.0"],"schemaVersion":1,"symbols":["github.com/Masterminds/semver/v3.NewConstraint"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/Masterminds/semver/v3@v3.3.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/Masterminds/semver/v3@v3.3.0","symbols":["github.com/Masterminds/semver/v3.NewConstraint"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26

require github.com/Masterminds/semver/v3 v3.3.0

github.com/Masterminds/semver/v3 v3.3.0 h1:B8LGeaivUe71a5qox1ICM/JLl0NqZSW5CHyL+hmvYS0=
github.com/Masterminds/semver/v3 v3.3.0/go.mod h1:4V+yj/TJE1HU9XfppCwVMZq3I84lprf4nC11bSS5beM=

package sample

import (
	"github.com/Masterminds/semver/v3"
)

// CheckVersion parses a constraint and checks whether the provided version string satisfies it.
func CheckVersion(constraintStr, versionStr string) (bool, error) {
	c, err := semver.NewConstraint(constraintStr)
	if err != nil {
		return false, err
	}
	v, err := semver.NewVersion(versionStr)
	if err != nil {
		return false, err
	}
	return c.Check(v), nil
}

// ValidateVersion validates whether a version string satisfies a constraint, returning any validation errors.
func ValidateVersion(constraintStr, versionStr string) (bool, []error, error) {
	c, err := semver.NewConstraint(constraintStr)
	if err != nil {
		return false, nil, err
	}
	v, err := semver.NewVersion(versionStr)
	if err != nil {
		return false, nil, err
	}
	valid, errs := c.Validate(v)
	return valid, errs, nil
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/Masterminds/semver/v3.NewConstraint in pkg:golang/github.com/Masterminds/semver/v3@v3.3.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/Masterminds/semver/v3@v3.3.0"
  ],
  "symbols": [
    "github.com/Masterminds/semver/v3.NewConstraint"
  ]
}

package test

import (
	"testing"

	"github.com/Masterminds/semver/v3"
)

func TestNewConstraintParsing(t *testing.T) {
	validExpressions := []string{
		">= 1.2.0, < 2.0.0",
		"~1.2.3",
		"^1.2.3",
		"1.x",
		"*",
	}
	for _, expr := range validExpressions {
		c, err := semver.NewConstraint(expr)
		if err != nil {
			t.Fatalf("expected valid constraint for %q, got error: %v", expr, err)
		}
		if c == nil {
			t.Fatalf("expected non-nil constraint for %q", expr)
		}
	}
}

func TestNewConstraintInvalid(t *testing.T) {
	invalidExpressions := []string{
		"invalid-constraint",
		">! 1.0.0",
		"== 1.2.3.4.5",
	}
	for _, expr := range invalidExpressions {
		c, err := semver.NewConstraint(expr)
		if err == nil {
			t.Fatalf("expected error parsing invalid constraint %q, got nil constraint: %v", expr, c)
		}
	}
}

func TestConstraintCheck(t *testing.T) {
	c, err := semver.NewConstraint(">= 1.2.0, < 2.0.0")
	if err != nil {
		t.Fatalf("unexpected error creating constraint: %v", err)
	}

	passVersion, err := semver.NewVersion("1.5.0")
	if err != nil {
		t.Fatalf("unexpected error parsing version: %v", err)
	}
	if !c.Check(passVersion) {
		t.Errorf("expected version %s to satisfy %s", passVersion, c)
	}

	failVersion, err := semver.NewVersion("2.1.0")
	if err != nil {
		t.Fatalf("unexpected error parsing version: %v", err)
	}
	if c.Check(failVersion) {
		t.Errorf("expected version %s NOT to satisfy %s", failVersion, c)
	}
}

func TestConstraintValidate(t *testing.T) {
	c, err := semver.NewConstraint(">= 2.0.0")
	if err != nil {
		t.Fatalf("unexpected error creating constraint: %v", err)
	}

	vValid, err := semver.NewVersion("2.5.0")
	if err != nil {
		t.Fatalf("unexpected error parsing version: %v", err)
	}
	valid, errs := c.Validate(vValid)
	if !valid || len(errs) != 0 {
		t.Errorf("expected Validate to succeed for %s, got valid=%v, errs=%v", vValid, valid, errs)
	}

	vInvalid, err := semver.NewVersion("1.9.0")
	if err != nil {
		t.Fatalf("unexpected error parsing version: %v", err)
	}
	valid, errs = c.Validate(vInvalid)
	if valid || len(errs) == 0 {
		t.Errorf("expected Validate to fail for %s, got valid=%v, errs=%v", vInvalid, valid, errs)
	}
}