index.js

import os from 'node:os';
import {execaSync} from 'execa';

// Reference: https://www.gaijin.at/en/lstwinver.php
// Windows 11 reference: https://docs.microsoft.com/en-us/windows/release-health/windows11-release-information
const names = new Map([
	['10.0.2', '11'], // It's unclear whether future Windows 11 versions will use this version scheme: https://github.com/sindresorhus/windows-release/pull/26/files#r744945281
	['10.0', '10'],
	['6.3', '8.1'],
	['6.2', '8'],
	['6.1', '7'],
	['6.0', 'Vista'],
	['5.2', 'Server 2003'],
	['5.1', 'XP'],
	['5.0', '2000'],
	['4.90', 'ME'],
	['4.10', '98'],
	['4.03', '95'],
	['4.00', '95'],
]);

export default function windowsRelease(release) {
	const version = /(\d+\.\d+)(?:\.(\d+))?/.exec(release || os.release());

	if (release && !version) {
		throw new Error('`release` argument doesn\'t match `n.n`');
	}

	let ver = version[1] || '';
	const build = version[2] || '';

	// Server 2008, 2012, 2016, and 2019 versions are ambiguous with desktop versions and must be detected at runtime.
	// If `release` is omitted or we're on a Windows system, and the version number is an ambiguous version
	// then use `wmic` to get the OS caption: https://msdn.microsoft.com/en-us/library/aa394531(v=vs.85).aspx
	// If `wmic` is obsolete (later versions of Windows 10), use PowerShell instead.
	// If the resulting caption contains the year 2008, 2012, 2016, 2019 or 2022, it is a server version, so return a server OS name.
	if ((!release || release === os.release()) && ['6.1', '6.2', '6.3', '10.0'].includes(ver)) {
		let stdout;
		try {
			stdout = execaSync('wmic', ['os', 'get', 'Caption']).stdout || '';
		} catch {
			stdout = execaSync('powershell', ['(Get-CimInstance -ClassName Win32_OperatingSystem).caption']).stdout || '';
		}

		const year = (stdout.match(/2008|2012|2016|2019|2022/) || [])[0];

		if (year) {
			return `Server ${year}`;
		}
	}

	// Windows 11
	if (ver === '10.0' && build.startsWith('2')) {
		ver = '10.0.2';
	}

	return names.get(ver);
}