semver 6.3.1: diff

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.diff in pkg:npm/semver@6.3.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/semver@6.3.1
Demonstrate these symbols/APIs:
  - semver.diff

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:sha256:1f060835bec930a3f265aa950a82fdb23f77cd944512a1298bd2ba1d1c44f231","contract":["semver.diff returns major, minor, or patch release difference for non-prerelease version transitions","semver.diff returns premajor, preminor, or prepatch release difference when changing release segment with prerelease identifier","semver.diff returns prerelease when version numbers match and only prerelease identifiers differ","semver.diff returns null when comparing two identical versions","semver.diff throws TypeError when provided with an invalid version string or null","semver.diff accepts SemVer instances directly as arguments"],"goal":"verify semver.diff in pkg:npm/semver@6.3.1","kind":"HOW","packages":["pkg:npm/semver@6.3.1"],"schemaVersion":1,"symbols":["semver.diff"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/semver@6.3.1"],"schemaVersion":1,"subject":"pkg:npm/semver@6.3.1","symbols":["semver.diff"],"verifierAdapter":"node-typescript@1"}

import semver from 'semver';

/**
 * Determines the difference type between two version strings or SemVer instances.
 * @param {string|import('semver').SemVer} v1 - First version.
 * @param {string|import('semver').SemVer} v2 - Second version.
 * @param {object|string} [optionsOrLoose] - Comparison options or loose boolean.
 * @returns {import('semver').ReleaseType|null} Release difference type or null if equal.
 */
export function diffVersions(v1, v2, optionsOrLoose) {
  return semver.diff(v1, v2, optionsOrLoose);
}

export { semver };
export default semver;

{
  "name": "sample-semver-diff",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-semver-diff",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "semver": "6.3.1"
      }
    },
    "node_modules/semver": {
      "version": "6.3.1",
      "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
      "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA==",
      "license": "ISC",
      "bin": {
        "semver": "bin/semver.js"
      }
    }
  }
}

{
  "name": "sample-semver-diff",
  "version": "1.0.0",
  "description": "Verify semver.diff in pkg:npm/semver@6.3.1",
  "main": "index.mjs",
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "semver": "6.3.1"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify semver.diff in pkg:npm/semver@6.3.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/semver@6.3.1"
  ],
  "symbols": [
    "semver.diff"
  ]
}

import assert from 'node:assert/strict';
import semver, { diffVersions } from '../index.mjs';

// 1. semver.diff returns major, minor, or patch release difference for non-prerelease version transitions
{
  assert.equal(semver.diff('1.2.3', '2.0.0'), 'major');
  assert.equal(semver.diff('1.2.3', '1.3.0'), 'minor');
  assert.equal(semver.diff('1.2.3', '1.2.4'), 'patch');
  assert.equal(diffVersions('0.1.0', '1.0.0'), 'major');
  assert.equal(diffVersions('0.1.0', '0.2.0'), 'minor');
  assert.equal(diffVersions('0.1.0', '0.1.1'), 'patch');
}

// 2. semver.diff returns premajor, preminor, or prepatch release difference when changing release segment with prerelease identifier
{
  assert.equal(semver.diff('1.2.3', '2.0.0-alpha.0'), 'premajor');
  assert.equal(semver.diff('1.2.3', '1.3.0-rc.1'), 'preminor');
  assert.equal(semver.diff('1.2.3', '1.2.4-beta.0'), 'prepatch');
  assert.equal(diffVersions('1.0.0', '2.0.0-0'), 'premajor');
  assert.equal(diffVersions('1.0.0', '1.1.0-0'), 'preminor');
  assert.equal(diffVersions('1.0.0', '1.0.1-0'), 'prepatch');
}

// 3. semver.diff returns prerelease when version numbers match and only prerelease identifiers differ
{
  assert.equal(semver.diff('1.2.3-alpha.0', '1.2.3-alpha.1'), 'prerelease');
  assert.equal(semver.diff('1.2.3-alpha.0', '1.2.3-beta.0'), 'prerelease');
  assert.equal(diffVersions('1.0.0-rc.1', '1.0.0-rc.2'), 'prerelease');
}

// 4. semver.diff returns null when comparing two identical versions
{
  assert.equal(semver.diff('1.2.3', '1.2.3'), null);
  assert.equal(semver.diff('2.0.0-alpha.1', '2.0.0-alpha.1'), null);
  assert.equal(diffVersions('0.0.1', '0.0.1'), null);
}

// 5. semver.diff throws TypeError when provided with an invalid version string or null
{
  assert.throws(
    () => {
      semver.diff('not-a-version', '1.2.3');
    },
    {
      name: 'TypeError'
    }
  );
  assert.throws(
    () => {
      semver.diff('1.2.3', 'invalid');
    },
    {
      name: 'TypeError'
    }
  );
  assert.throws(
    () => {
      diffVersions(null, '1.2.3');
    },
    {
      name: 'TypeError'
    }
  );
}

// 6. semver.diff accepts SemVer instances directly as arguments
{
  const v1 = new semver.SemVer('1.2.3');
  const v2 = new semver.SemVer('2.0.0');
  const v3 = new semver.SemVer('1.2.3');
  assert.equal(semver.diff(v1, v2), 'major');
  assert.equal(diffVersions(v1, v3), null);
}

console.log('All semver.diff contract tests passed.');