github.com/Masterminds/semver/v3 v3.2.0: semver.Constraints

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 semver.Constraints in pkg:golang/github.com/Masterminds/semver/v3@v3.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/Masterminds/semver/v3@v3.2.0
Demonstrate these symbols/APIs:
  - semver.Constraints

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:sha256:6d8c53be168c587be521f7018e91f66f9e9565b7f60fc6a87576a92ab5eb4437","contract":["semver.NewConstraint parses valid semantic version constraint expressions into a Constraints object","Constraints.Check evaluates whether a Version satisfies constraint ranges and comparison operators","Constraints.Validate returns true with no validation errors when a Version matches the constraint, and false with error details when it does not","semver.NewConstraint returns an error when given an invalid constraint expression"],"goal":"verify semver.Constraints in pkg:golang/github.com/Masterminds/semver/v3@v3.2.0","kind":"HOW","packages":["pkg:golang/github.com/Masterminds/semver/v3@v3.2.0"],"schemaVersion":1,"symbols":["semver.Constraints"]},"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/Masterminds/semver/v3@v3.2.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/Masterminds/semver/v3@v3.2.0","symbols":["semver.Constraints"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/Masterminds/semver/v3 v3.2.0

github.com/Masterminds/semver/v3 v3.2.0 h1:3MEsd0SM6jqZojhjLWWeBY+Kcjy9i6MQAeY7YgDP83g=
github.com/Masterminds/semver/v3 v3.2.0/go.mod h1:qvl/7zhW3nngYb5+80sSMF+FG2BjYrf8m9wsX0PNOMQ=

package main

import (
	"fmt"
	"log"

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

func main() {
	constraintStr := ">= 1.2.0, < 2.0.0"
	c, err := semver.NewConstraint(constraintStr)
	if err != nil {
		log.Fatalf("failed to parse constraint: %v", err)
	}

	v1 := semver.MustParse("1.5.0")
	v2 := semver.MustParse("2.1.0")

	fmt.Printf("Constraint: %s\n", c.String())
	fmt.Printf("Is %s valid? %v\n", v1, c.Check(v1))
	fmt.Printf("Is %s valid? %v\n", v2, c.Check(v2))
}

{
  "schemaVersion": 1,
  "goal": "verify semver.Constraints in pkg:golang/github.com/Masterminds/semver/v3@v3.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/Masterminds/semver/v3@v3.2.0"
  ],
  "symbols": [
    "semver.Constraints"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: semver.NewConstraint parses valid semantic version constraint expressions into a Constraints object
	c1, err := semver.NewConstraint(">= 1.2.0, < 2.0.0")
	if err != nil || c1 == nil {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected valid Constraints object, got err=%v\n", err)
		os.Exit(1)
	}

	// Assertion 2: Constraints.Check evaluates whether a Version satisfies constraint ranges and comparison operators
	vMatch := semver.MustParse("1.5.0")
	vMismatch := semver.MustParse("2.0.0")
	vLower := semver.MustParse("1.1.9")

	if !c1.Check(vMatch) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected %s to satisfy %s\n", vMatch, c1)
		os.Exit(1)
	}
	if c1.Check(vMismatch) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected %s to not satisfy %s\n", vMismatch, c1)
		os.Exit(1)
	}
	if c1.Check(vLower) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected %s to not satisfy %s\n", vLower, c1)
		os.Exit(1)
	}

	// Assertion 3: Constraints.Validate returns true with no validation errors when a Version matches the constraint, and false with error details when it does not
	valid, errs := c1.Validate(vMatch)
	if !valid || len(errs) != 0 {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected valid=true, len(errs)=0 for %s, got valid=%v, errs=%v\n", vMatch, valid, errs)
		os.Exit(1)
	}
	validMismatch, errsMismatch := c1.Validate(vMismatch)
	if validMismatch || len(errsMismatch) == 0 {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected valid=false, len(errs)>0 for %s, got valid=%v, errs=%v\n", vMismatch, validMismatch, errsMismatch)
		os.Exit(1)
	}

	// Assertion 4: semver.NewConstraint returns an error when given an invalid constraint expression
	_, invalidErr := semver.NewConstraint("invalid @#$ constraint")
	if invalidErr == nil {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected error for invalid constraint expression, got nil\n")
		os.Exit(1)
	}

	fmt.Println("All contract assertions passed.")
}