luxon 3.6.1: DateTime

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 luxon.DateTime in pkg:npm/luxon@3.6.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/luxon@3.6.1
Demonstrate these symbols/APIs:
  - luxon.DateTime

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:sha256:577b7da4ad88297959ad16d82892d3d7a417b62b9758cda5a435dc763a496e23","contract":["assert DateTime is exported as a function/class from luxon","assert DateTime.fromISO parses ISO 8601 strings into valid UTC DateTime instances","assert DateTime.utc creates valid UTC DateTime instances with exact date components","assert DateTime.plus performs date arithmetic by adding duration offsets","assert DateTime.fromISO returns invalid DateTime with invalidReason on malformed input"],"goal":"verify luxon.DateTime in pkg:npm/luxon@3.6.1","kind":"HOW","packages":["pkg:npm/luxon@3.6.1"],"schemaVersion":1,"symbols":["luxon.DateTime"]},"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/luxon@3.6.1"],"schemaVersion":1,"subject":"pkg:npm/luxon@3.6.1","symbols":["luxon.DateTime"],"verifierAdapter":"node-typescript@1"}

import { DateTime } from 'luxon';

/**
 * Creates a UTC DateTime from an ISO string.
 * @param {string} isoString
 * @returns {DateTime}
 */
export function parseIsoUtc(isoString) {
  return DateTime.fromISO(isoString, { zone: 'utc' });
}

/**
 * Creates a DateTime in UTC for specific date components.
 * @param {number} year
 * @param {number} month
 * @param {number} day
 * @param {number} hour
 * @param {number} minute
 * @param {number} second
 * @returns {DateTime}
 */
export function createUtcDateTime(year, month, day, hour = 0, minute = 0, second = 0) {
  return DateTime.utc(year, month, day, hour, minute, second);
}

/**
 * Formats a DateTime instance to an ISO 8601 string.
 * @param {DateTime} dt
 * @returns {string|null}
 */
export function formatToIso(dt) {
  return dt.toISO();
}

/**
 * Adds a duration object to a DateTime.
 * @param {DateTime} dt
 * @param {object} durationObj
 * @returns {DateTime}
 */
export function addDuration(dt, durationObj) {
  return dt.plus(durationObj);
}

export { DateTime };

{
  "name": "sample-luxon-datetime",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-luxon-datetime",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "luxon": "3.6.1"
      }
    },
    "node_modules/luxon": {
      "version": "3.6.1",
      "resolved": "https://registry.npmjs.org/luxon/-/luxon-3.6.1.tgz",
      "integrity": "sha512-tJLxrKJhO2ukZ5z0gyjY1zPh3Rh88Ej9P7jNrZiHMUXHae1yvI2imgOZtL1TO8TW6biMMKfTtAOoEJANgtWBMQ==",
      "license": "MIT",
      "engines": {
        "node": ">=12"
      }
    }
  }
}

{
  "name": "sample-luxon-datetime",
  "version": "1.0.0",
  "description": "Clean-room sample verifying luxon.DateTime functionality",
  "type": "module",
  "main": "index.js",
  "license": "MIT-0",
  "scripts": {
    "contract": "node test/contract.mjs"
  },
  "dependencies": {
    "luxon": "3.6.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify luxon.DateTime in pkg:npm/luxon@3.6.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/luxon@3.6.1"
  ],
  "symbols": [
    "luxon.DateTime"
  ]
}

import assert from 'node:assert/strict';
import { DateTime, parseIsoUtc, createUtcDateTime, formatToIso, addDuration } from '../index.js';

// 1. Verify DateTime import and type
assert.equal(typeof DateTime, 'function', 'DateTime should be exported as a class/function');

// 2. Verify DateTime.fromISO creates valid UTC DateTime instances
const iso = '2025-07-09T12:30:00.000Z';
const dtFromIso = parseIsoUtc(iso);
assert.equal(dtFromIso.isValid, true, 'DateTime.fromISO should return a valid DateTime');
assert.equal(dtFromIso.zoneName, 'UTC', 'DateTime zone should be UTC');
assert.equal(formatToIso(dtFromIso), iso, 'formatToIso should match original ISO string');
assert.equal(dtFromIso.year, 2025, 'Year should match');
assert.equal(dtFromIso.month, 7, 'Month should match');
assert.equal(dtFromIso.day, 9, 'Day should match');
assert.equal(dtFromIso.hour, 12, 'Hour should match');
assert.equal(dtFromIso.minute, 30, 'Minute should match');
assert.equal(dtFromIso.second, 0, 'Second should match');

// 3. Verify DateTime.utc construction
const dtUtc = createUtcDateTime(2025, 7, 9, 12, 30, 0);
assert.equal(dtUtc.isValid, true, 'DateTime.utc should return a valid DateTime');
assert.equal(dtUtc.toISO(), iso, 'DateTime.utc ISO string should match expected value');
assert.equal(dtUtc.equals(dtFromIso), true, 'DateTime created via fromISO and utc should be equal');

// 4. Verify arithmetic with plus
const dtPlusOneDay = addDuration(dtFromIso, { days: 1 });
assert.equal(dtPlusOneDay.isValid, true, 'DateTime after addition should be valid');
assert.equal(dtPlusOneDay.day, 10, 'Day should be incremented');
assert.equal(dtPlusOneDay.toISO(), '2025-07-10T12:30:00.000Z', 'Resulting ISO string should match expected added date');

// 5. Verify invalid date handling
const invalidDt = DateTime.fromISO('not-a-valid-date');
assert.equal(invalidDt.isValid, false, 'Invalid ISO string should produce an invalid DateTime');
assert.ok(invalidDt.invalidReason, 'Invalid DateTime should provide an invalidReason');

console.log('All luxon.DateTime contract assertions passed.');