lodash.mixin.js

/**
     * This function compares between two version numbers formatted x.x.x...
     * @param v1 - String
     * @param v2 - String
     * @returns {int}
     *  -1 if v1 is larger
     *  1 if v2 is larger
     *  0 if v1 & v2 are equal
     */
    versionCompare: function (v1, v2) {
        if (v1) {
            var v1parts = v1.split('.');
        } else {
            if (v2) {
                return 1; // v1 is missing. Treat v2 as larger.
            } else {
                return 0; // Both are undefined.
            }
        }

        if (v2) {
            var v2parts = v2.split('.');
        } else {
            return -1; // v2 is missing. Treat v1 as larger.
        }

        // Force equal length on both arrays:
        while (_.size(v1parts) != _.size(v2parts)) {
            if (_.size(v1parts) > _.size(v2parts)) {
                v2parts.push(0);
            } else { // (_.size(v1parts) < _.size(v2parts)
                v1parts.push(0);
            }
        }

        // Assuming equal length:
        for (var i = 0; i < v1parts.length; ++i) {
            if (v1parts[i] < v2parts[i]) { //v2 part is larger.
                return 1;
            } else if (v1parts[i] > v2parts[i]) { //v1 part is larger.
                return -1;
            } // Else equal
        }
        return 0;
    }