validations and extends

// ---------- extends ----------
Object.prototype.extends = function (parent) {
    this.prototype = Object.create(parent.prototype);
    this.prototype.constructor = this;
}

// ---------- is Number ----------
Number.prototype.validateIsNumber = function (value, variableName, minValue, maxValue) {
    if (typeof (value) != 'number') {
        throw new Error(variableName + " should be a number!");
    }
}

// ---------- is Integer ----------
Number.prototype.isInteger = function isInteger(x) {
    return ((x ^ 0) === x);
}

// ---------- validate integer range ----------
Number.prototype.validateIntegerRange = function (value, variableName, minValue, maxValue) {
    if (typeof (value) != 'number') {
        throw new Error(variableName + " should be a number!");
    }

    if (value !== parseInt(value, 10)) {
        throw new Error(variableName + " should be integer!");
    }

    if (value < minValue || value > maxValue) {
        throw new Error(variableName + " should be integer in the range [" + minValue + "..." + maxValue + "]!");
    }
}

// ---------- validate non-empty string ----------
String.prototype.validateNonEmptyString = function (value, variableName) {
    if (typeof (value) != 'string' || !value) {
        throw new Error(variableName + " should be non-empty string!");
    }
}

// ---------- validate boolean ----------
Boolean.prototype.validateBoolean = function (value, variableName) {
    if (typeof (value) != 'boolean') {
        throw new Error(variableName + " should be a boolean value!");
    }
}

// ---------- validate non-empty object ----------
Object.prototype.validateNonEmptyObject = function (value, className, variableName) {
    if (! (value instanceof className)) {
        throw new Error(variableName + " should be non-empty " + className.prototype.constructor.name + "!");
    }
}