node/deps/npm/node_modules/node-uuid/test/test.js

if (typeof(uuid) == 'undefined') {
  uuid = require('../uuid');
}

var UUID_FORMAT = /[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89a-fAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}/;
var N = 1e5;

function log(msg) {
  if (typeof(document) != 'undefined') {
    document.write('<div>' + msg + '</div>');
  }
  if (typeof(console) != 'undefined') {
    console.log(msg);
  }
}

function rate(msg, t) {
  log(msg + ': ' + (N / (Date.now() - t) * 1e3 | 0) + ' uuids/second');
}

// Perf tests
log('- - - Performance Data - - -');
for (var i = 0, t = Date.now(); i < N; i++) uuid();
rate('uuid()', t);
for (var i = 0, t = Date.now(); i < N; i++) uuid('binary');
rate('uuid(\'binary\')', t);
var buf = new uuid.BufferClass(16);
for (var i = 0, t = Date.now(); i < N; i++) uuid('binary', buf);
rate('uuid(\'binary\', buffer)', t);

var counts = {}, max = 0;

var b  = new uuid.BufferClass(16);
for (var i = 0; i < N; i++) {
  id = uuid();
  if (!UUID_FORMAT.test(id)) {
    throw Error(id + ' is not a valid UUID string');
  }

  if (id != uuid.unparse(uuid.parse(id))) {
    throw Error(id + ' does not parse/unparse');
  }

  // Count digits for our randomness check
  var digits = id.replace(/-/g, '').split('');
  for (var j = digits.length-1; j >= 0; j--) {
    var c = digits[j];
    max = Math.max(max, counts[c] = (counts[c] || 0) + 1);
  }
}

// Get %'age an actual value differs from the ideal value
function divergence(actual, ideal) {
  return Math.round(100*100*(actual - ideal)/ideal)/100;
}

log('<br />- - - Distribution of Hex Digits (% deviation from ideal) - - -');

// Check randomness
for (var i = 0; i < 16; i++) {
  var c = i.toString(16);
  var bar = '', n = counts[c], p = Math.round(n/max*100|0);

  // 1-3,5-8, and D-F: 1:16 odds over 30 digits
  var ideal = N*30/16;
  if (i == 4) {
    // 4: 1:1 odds on 1 digit, plus 1:16 odds on 30 digits
    ideal = N*(1 + 30/16);
  } else if (i >= 8 && i <= 11) {
    // 8-B: 1:4 odds on 1 digit, plus 1:16 odds on 30 digits
    ideal = N*(1/4 + 30/16);
  } else {
    // Otherwise: 1:16 odds on 30 digits
    ideal = N*30/16;
  }
  var d = divergence(n, ideal);

  // Draw bar using UTF squares (just for grins)
  var s = n/max*50 | 0;
  while (s--) bar += '=';

  log(c + ' |' + bar + '| ' + counts[c] + ' (' + d + '%)');
}