tiny-version-compare/index.js

Compare two software versions, with any number of points (<1KB)

const splitDev = v => String(v).split('-');

const splitSub = v => String(v)
	.replace(/^[vr]/, '') // Drop initial 'v' or 'r'
	.replace(/([a-z]+)/gi, '.$1.') // Sort each word separately
	.replace(/\.+/g, '.') // Trim repeating separators
	.split('.');

// Development versions are considered "negative",
// but localeCompare doesn't handle negative numbers.
// This offset is applied to reset the lowest development version to 0
const offset = part => {
	// Not numeric, return as is
	if (isNaN(part)) {
		return part;
	}

	return 5 + Number(part);
};

const parseSub = part => {
	// Missing, consider it zero
	if (typeof part === 'undefined') {
		return 0;
	}

	// Sort development versions
	switch (part.toLowerCase()) {
		case 'dev': return -5;
		case 'alpha': case 'a': return -4;
		case 'beta': case 'b': return -3;
		case 'rc': case 'c': return -2;
		case 'pre': return -1;
		default:
	}

	// Return as is, it’s either a plain number or text that will be sorted alphabetically
	return part;
};

function compareSubs(a, b) {
	for (let i = 0; i < a.length || i < b.length; i++) {
		const ai = offset(parseSub(a[i]));
		const bi = offset(parseSub(b[i]));
		const sort = String(ai).localeCompare(bi, 'en', {
			numeric: true,
		});

		// Once the difference is found,
		// stop comparing the rest of the parts
		if (sort !== 0) {
			return sort;
		}
	}

	return 0;
}

export default function compareVersions(a, b) {
	if (a === b) {
		return 0;
	}

	const [aMain, aDev] = splitDev(a).map(splitSub);
	const [bMain, bDev] = splitDev(b).map(splitSub);

	const mainSort = compareSubs(aMain, bMain);
	if (mainSort !== 0) {
		return mainSort;
	}

	if (aDev && !bDev) {
		return -1;
	}

	if (!aDev && bDev) {
		return 1;
	}

	if (aDev && bDev) {
		return compareSubs(aDev, bDev);
	}

	// No difference found
	return 0;
}