assertions.js

(function($, QUnit){
  QUnit.assert.hasSelector = function(node, selector) {
    var el = $('<div>' + node.outerHTML + '</div>'),
      ok = el.has(selector);

    this.push(ok, el.html(), selector, "expected to have selector '" +  selector +"'.");
  };

  QUnit.assert.hasLink = function(node, text, href) {
    var el = $('<div>' + node.outerHTML + '</div>'),
        anchors = el.find('a').filter(function() {
          return this.text === text && (!href || this.href === href);
        });

    this.push(!!anchors.length, el.html(), text, "expected to have link '" + text + "'('" + href + "')");
  }

  QUnit.assert.hasText = function(node, selector, text) {
    this.hasSelector(node, selector);
    var el = $('<div>' + node.outerHTML + '</div>').find(selector);

    if (el.length) {
      var source = el.text(),
          ok = el.text().includes(text);
      this.push(ok, source, text, "expected '" +  selector + "' to have contain '" + text + "', but contains '" + source + "' instead.");
    }
  };
})(jQuery, QUnit);

react.js

(function(QUnit, document) {
  var React = require('react');

  QUnit.assert.renderComponent = function(Component, props, callback) {
    var element = React.createElement(Component, props),
        root = document.createElement('div'),
        done = this.async();

    var instance = React.render(element, root, function() {
      setTimeout(function() {
        callback(root.childNodes[0], instance);
        done();
      })
    });
  }
})(QUnit, document);

tweet_test.js

var TweetMessage = require('components/messages/tweet');

QUnit.module('Components.Messages.Tweet');

QUnit.test('renders the tweet message element', function(assert) {
  var message = { author: { name: 'Test Author', avatar_url: '' }, body: 'depois de um dia meio chato\nmuito friu -- @rondi, https://twitter.com/Rondi/status/108781678809460736' };

  assert.renderComponent(TweetMessage, { message: message }, function(node) {
    assert.hasSelector(node, '.chat-message-text-container');
    assert.hasSelector(node, 'blockquote.embedded-tweet');

    assert.hasText(node, 'blockquote p', 'depois de um dia meio chatomuito friu');

    assert.hasLink(node, 'rondi', 'https://twitter.com/rondi');
    assert.hasLink(node, 'https://twitter.com/Rondi/status/108781678809460736', 'https://twitter.com/Rondi/status/108781678809460736');
  });
});