Simple sem ver class.

version.js

function Version(versionString) {
    this.version = {
        major: 0,
        minor: 0,
        patch: 0
    };
    if (versionString) {
        this.parse(versionString);
    }
}

Version.prototype.parse = function (versionString) {
    var chunks = versionString.split('.');
    var getIntValue = function (value) {
        var i = parseInt(value, 10);
        return isNaN(i) ? 0 : i;
    }
    switch (chunks.length) {
        case 3:
            this.version.patch = getIntValue(chunks[2]);
        case 2:
            this.version.minor = getIntValue(chunks[1]);
        case 1:
            this.version.major = getIntValue(chunks[0]);
            break;
        default:
            this.version.major = getIntValue(versionString);
    }
}

Version.prototype.toArray = function (truncate) {
    var output = [this.version.major, this.version.minor, this.version.patch];
    if (truncate) {
        var newLength = output.length;
        for (var i = output.length - 1; i > 0; --i) {
            if (output[i] <= 0) {
                newLength--;
            } else {
                break;
            }
        }
        return output.slice(0, newLength);
    }
    return output;
}

Version.prototype.toString = function (truncate) {
    return this.toArray(truncate).join('.')
}

/*
 * Return 1 if the receiver is greater than the argument.
 * Return 0 if the receiver and the argument are equal.
 * Return -1 if the receiver is less than the argument.
 **/
Version.prototype.compare = function (toVersion) {
    var fma = this.version.major;
    var fmi = this.version.minor;
    var fpa = this.version.patch;
    var tma = toVersion.version.major;
    var tmi = toVersion.version.minor;
    var tpa = toVersion.version.patch;
    if (fma == tma && fmi == tmi && fpa == tpa) {
        return 0;
    } else if (fma > tma ||
               (fma == tma && fmi > tmi) ||
               (fma == tma && fmi == tmi && fpa > tpa)
              ) {
        return 1;
    }
    return -1;
}

Version.prototype.compareToVersionString = function (toVersionString) {
    return this.compare(new Version(toVersionString));
}

module.exports = Version;