Kaskata validations

// ---------- string is null or empty ----------
String.prototype.isNullOrEmpty = function (varName) {
    if (typeof (this.valueOf()) != 'string') {
        throw new Error(varName + "must be String");
    }

    if (!this.valueOf()) {
        throw new Error(varName + " cannot be undefined or empty");
    }
}

// ---------- is integer in range ----------
Number.prototype.isIntegerAndInRange = function (minValue, maxValue, varName) {
    if (typeof ( this.valueOf() ) != 'number') {
        throw new Error(varName + " must be Number.");
    }
    if (this === parseInt( this.valueOf() , 10)) {
        throw new Error(varName + " must be Integer.");
    }
    if (this.valueOf() < minValue || this.valueOf() > maxValue) {
        throw new Error(varName + " must be Integer in range[" + minValue + "..." + maxValue + "].");
    }
    return true;
}

// ---------- is boolean ----------
Boolean.prototype.isBoolean = function (varName) {
    if (typeof (this.valueOf()) != 'boolean') {
        throw new Error(varName + " must be Boolean value.");
    }
    return true;
}