n-way comparison of string parts using Array.every

gistfile1.js

/**
 * Splits a string on a given separator and compares each part
 * @returns {Boolean} True is all parts are equal, false if not
 */ 
String.prototype.equate = function (separator) {
    return this.split(separator).every(function(element, index, array){
            return (element === array[0]);
            });    
        }

// true
console.log("this this this".equate(' '));

// false
console.log("this that this".equate(' '));

// true
console.log("bbbbbbbbb".equate(''));

// true
console.log("1 2 3 4 5 6 7 8 9".equate(/(d)/));

// true (no separator = one string)
console.log("whateverwewant".equate());