Semver Comparison

semver-compare.js

function test() {
    var results = [];
    results.push(compareSemver("1.8.3", "1.8.3", "=="));
    results.push(compareSemver("1.9.1", "1.11.1", "<"));
    results.push(compareSemver("1.5.3", "1.9", "<"));
    results.push(compareSemver("1.3.2", "1.10.2", "<="));
    results.push(compareSemver("1.3.2", "1.3.2", "<="));
    results.push(compareSemver("1.11.1", "1.9.1", ">"));
    results.push(compareSemver("1.11.1", "1.11.0", ">"));
    results.push(compareSemver("1.10.2", "1.5.2", ">="));
    console.log(results);
}

function compareSemver(v1, v2, op) {
	var result = false,
        p1 = normalizeSemVer(v1),
	    p2 = normalizeSemVer(v2);

	if (/^===?$/.test(op)) {
		result = semverEqual(p1, p2, 3);
	} else if (/^</.test(op)) {
		result = p1[0] < p2[0] || (semverEqual(p1, p2, 1) && p1[1] < p2[1]) || (semverEqual(p1, p2, 2) && p1[2] < p2[2]);
		if (!result && /^<=$/.test(op)) {
			result = semverEqual(p1, p2, 3);
		}
	} else if (/^>/.test(op)) {
		result = p1[0] > p2[0] || (semverEqual(p1, p2, 1) && p1[1] > p2[1]) || (semverEqual(p1, p2, 2) && p1[2] > p2[2]);
	}
	if (!result && /^[<>]=$/.test(op)) {
		result = semverEqual(p1, p2, 3);
	}
	return result;
}
function semverEqual(p1, p2, cnt) {
	var i, equal = true;
	for (i=0; i<cnt; ++i) {
		equal = equal && (p1[i] === p2[i]);
	}
	return equal;
}
function normalizeSemVer(v) {
	if (v.length < 1) { return "0.0.0"; }
	var p = v.toString().split('.');
	if (p.length < 2) { p[1] = "0"; }
	if (p.length < 3) { p[2] = "0"; }
	return [Number(p[0]), Number(p[1]), Number(p[2])];
}

test();