defineProperty vs standard property assignment

defineProperty.js

const TEST_LOOP_COUNT = 1e5;
const VAL = "woo";
const DESC = { value: VAL, configurable: true, enumerable: true, writable: true };
const propNames = [ "i0", "i1", "i2", "i3", "i4", "i5", "i6", "i7", "i8", "i9" ];
const PROP_COUNT = propNames.length;


function literal () {
    return {
      [propNames[0]]: VAL,
      [propNames[1]]: VAL,
      [propNames[2]]: VAL,
      [propNames[3]]: VAL,
      [propNames[4]]: VAL,
      [propNames[5]]: VAL,
      [propNames[6]]: VAL,
      [propNames[7]]: VAL,
      [propNames[8]]: VAL,
      [propNames[9]]: VAL,
    }
}


function assign () {
  var obj = {};
  obj[propNames[0]] = VAL;
  obj[propNames[1]] = VAL;
  obj[propNames[2]] = VAL;
  obj[propNames[3]] = VAL;
  obj[propNames[4]] = VAL;
  obj[propNames[5]] = VAL;
  obj[propNames[6]] = VAL;
  obj[propNames[7]] = VAL;
  obj[propNames[8]] = VAL;
  obj[propNames[9]] = VAL;
  return obj;
}


function assignLoop () {
  var obj = {};
  for (var i=0; i<PROP_COUNT; i++) {
    obj[propNames[i]] = VAL;
  }
  return obj;
}


function defineProperty () {
  var obj = {};
  Object.defineProperty(obj, propNames[0], DESC);
  Object.defineProperty(obj, propNames[1], DESC);
  Object.defineProperty(obj, propNames[2], DESC);
  Object.defineProperty(obj, propNames[3], DESC);
  Object.defineProperty(obj, propNames[4], DESC);
  Object.defineProperty(obj, propNames[5], DESC);
  Object.defineProperty(obj, propNames[6], DESC);
  Object.defineProperty(obj, propNames[7], DESC);
  Object.defineProperty(obj, propNames[8], DESC);
  Object.defineProperty(obj, propNames[9], DESC);
  return obj;
}


function definePropertyLoop () {
  var obj = {};
  for (var i=0; i<PROP_COUNT; i++) {
    Object.defineProperty(obj, propNames[i], DESC);
  }
  return obj;
}


// Measurement Infrastructure

function test (fn) {
var container = [];
    for (var i=0; i<TEST_LOOP_COUNT; i++) {
      container.push(fn());
    }
    return container;
}


var OBJECT_CREATOR_FNS = [
  literal,
  assign,
  assignLoop,
  defineProperty,
  definePropertyLoop,
]


// Warmup
for (const fn of OBJECT_CREATOR_FNS) {
  test(fn);
}

// Measure
for (const fn of OBJECT_CREATOR_FNS) {
  console.time(fn.name);
  var ret = test(fn);
  console.timeEnd(fn.name);
  if (ret.length !== TEST_LOOP_COUNT) { throw e; }
}