semver 6.3.1: lt

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.lt 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.lt
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:sha256:81caeb5b604b9b94c4f8098d72e59504787736786b847d9cfe60cac983bd3e02","constraints":{"executionContext":"node"},"contract":["lt returns true when the first version is lower than the second version","lt returns false when the first version is greater than or equal to the second version","lt considers prerelease versions lower than the corresponding release version","lt ignores build metadata when comparing versions","lt supports loose option to parse prefixed or loose version strings","lt throws TypeError when an invalid version string is provided"],"goal":"verify semver.lt in pkg:npm/semver@6.3.1","kind":"HOW","packages":["pkg:npm/semver@6.3.1"],"schemaVersion":1,"symbols":["semver.lt"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","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.lt"],"verifierAdapter":"node-typescript@1"}

const semver = require('semver');

/**
 * Compare two versions and return true if v1 is less than v2.
 *
 * @param {string} v1 - First version string.
 * @param {string} v2 - Second version string.
 * @param {boolean|object} [options] - Optional loose mode flag or options object.
 * @returns {boolean} True if v1 is strictly less than v2.
 */
function isLessThan(v1, v2, options) {
  return semver.lt(v1, v2, options);
}

module.exports = {
  isLessThan,
};

{
  "name": "sample-semver-lt",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-semver-lt",
      "version": "1.0.0",
      "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-lt",
  "version": "1.0.0",
  "private": true,
  "description": "Verify semver.lt in pkg:npm/semver@6.3.1",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "semver": "6.3.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify semver.lt in pkg:npm/semver@6.3.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/semver@6.3.1"
  ],
  "symbols": [
    "semver.lt"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

const assert = require('node:assert');
const semver = require('semver');
const { isLessThan } = require('../index.js');

// 1. lt returns true when the first version is lower than the second version
{
  assert.strictEqual(isLessThan('1.2.3', '1.2.4'), true);
  assert.strictEqual(isLessThan('1.0.0', '2.0.0'), true);
  assert.strictEqual(semver.lt('1.2.3', '1.2.4'), true);
}

// 2. lt returns false when the first version is greater than or equal to the second version
{
  assert.strictEqual(isLessThan('1.2.4', '1.2.3'), false);
  assert.strictEqual(isLessThan('1.2.3', '1.2.3'), false);
  assert.strictEqual(semver.lt('2.0.0', '1.0.0'), false);
}

// 3. lt considers prerelease versions lower than the corresponding release version
{
  assert.strictEqual(isLessThan('1.0.0-alpha', '1.0.0-beta'), true);
  assert.strictEqual(isLessThan('1.0.0-alpha', '1.0.0'), true);
  assert.strictEqual(isLessThan('1.0.0-rc.1', '1.0.0-rc.2'), true);
}

// 4. lt ignores build metadata when comparing versions
{
  assert.strictEqual(isLessThan('1.0.0+build1', '1.0.0+build2'), false);
  assert.strictEqual(isLessThan('1.0.0+build2', '1.0.0+build1'), false);
  assert.strictEqual(isLessThan('1.0.0+build1', '1.0.1+build1'), true);
}

// 5. lt supports loose option to parse prefixed or loose version strings
{
  assert.strictEqual(isLessThan('v1.2.3', 'v1.2.4'), true);
  assert.strictEqual(isLessThan('=1.2.3', '1.2.4', { loose: true }), true);
  assert.strictEqual(isLessThan('=1.2.3', '1.2.4', true), true);
}

// 6. lt throws TypeError when an invalid version string is provided
{
  assert.throws(() => isLessThan('invalid', '1.2.3'), TypeError);
  assert.throws(() => isLessThan('1.2.3', 'not-a-version'), TypeError);
  assert.throws(() => isLessThan(null, '1.2.3'), TypeError);
}