if vs. assert vs. should

gistfile1.js

var assert = require('assert');
var should = require('should');

var a = 1;

var times = 1000000;
console.time('if ');
while(times--) {
  if (a === 1) ;
}
console.timeEnd('if ');

times = 1000000;
console.time('assert ');
while(times--) {
  assert.equal(a, 1);
}
console.timeEnd('assert ');

times = 1000000;
console.time('should ');
while(times--){
  a.should.equal(1);
}
console.timeEnd('should ');

gistfile2.eclass

$ node bench.js 
if : 2ms
assert : 14ms
should : 3144ms