text: var assert = require('assert');
  
  var uuid = require('../');
  
  var log = console.log;
  
  var generators = {
    v1: uuid.v1,
    v4: uuid.v4
  };
  
  var UUID_FORMAT = {
    v1: /[0-9a-f]{8}-[0-9a-f]{4}-1[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}/i,
    v4: /[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}/i
  };
  
  var N = 1e4;
  
  // Get %'age an actual value differs from the ideal value
  function divergence(actual, ideal) {
    return Math.round(100*100*(actual - ideal)/ideal)/100;
  }
  
  function rate(msg, t) {
    log(msg + ': ' + (N / (Date.now() - t) * 1e3 | 0) + ' uuids\/second');
  }
  
  for (var version in generators) {
    var counts = {}, max = 0;
    var generator = generators[version];
    var format = UUID_FORMAT[version];
  
    log('\nSanity check ' + N + ' ' + version + ' uuids');
    for (var i = 0, ok = 0; i < N; i++) {
      id = generator();
      if (!format.test(id)) {
        throw Error(id + ' is not a valid UUID string');
      }
  
      if (id != uuid.unparse(uuid.parse(id))) {
        assert(fail, id + ' is not a valid id');
      }
  
      // Count digits for our randomness check
      if (version == 'v4') {
        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);
        }
      }
    }
  
    // Check randomness for v4 UUIDs
    if (version == 'v4') {
      // Limit that we get worried about randomness. (Purely empirical choice, this!)
      var limit = 2*100*Math.sqrt(1/N);
  
      log('\nChecking v4 randomness.  Distribution of Hex Digits (% deviation from ideal)');
  
      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 += '=';
  
        assert(Math.abs(d) < limit, c + ' |' + bar + '| ' + counts[c] + ' (' + d + '% < ' + limit + '%)');
      }
    }
  }
  
  // Perf tests
  for (var version in generators) {
    log('\nPerformance testing ' + version + ' UUIDs');
    var generator = generators[version];
    var buf = new uuid.BufferClass(16);
  
    for (var i = 0, t = Date.now(); i < N; i++) generator();
    rate('uuid.' + version + '()', t);
  
    for (var i = 0, t = Date.now(); i < N; i++) generator('binary');
    rate('uuid.' + version + '(\'binary\')', t);
  
    for (var i = 0, t = Date.now(); i < N; i++) generator('binary', buf);
    rate('uuid.' + version + '(\'binary\', buffer)', t);
  }
  