old_contents: /*global describe, it */
  'use strict';
  
  var assert = require('assert');
  var viewport = require('./');
  
  describe('viewport()', function () {
      it('should return viewports', function (cb) {
          viewport('iphone 4', function (err, res) {
              cb(assert.strictEqual(res.length, 2));
          });
      });
  
      it('should return viewports using an array of keywords', function (cb) {
          viewport(['iphone 4', 'iphone 5'], function (err, res) {
              cb(assert.strictEqual(res.length, 5));
          });
      });
  
      it('should return all viewports', function (cb) {
          viewport(function (err, res) {
              cb(assert(res.length > 50));
          });
      });
  });
  
new_contents: 'use strict';
  
  var test = require('ava');
  var viewport = require('./');
  
  test('return viewports', function (t) {
      t.plan(2);
  
      viewport('iphone 4', function (err, res) {
          t.assert(!err);
          t.assert(res.length === 2);
      });
  });
  
  test('return viewports using an array of keywords', function (t) {
      t.plan(2);
  
      viewport(['iphone 4', 'iphone 5'], function (err, res) {
          t.assert(!err);
          t.assert(res.length === 5);
      });
  });
  
  test('return all viewports', function (t) {
      t.plan(2);
  
      viewport(function (err, res) {
          t.assert(!err);
          t.assert(res.length > 50);
      });
  });
  
subject: Use ava for testing