How do I mock a ReactClass dependency in Jest

I've built a reactJS class like so:

'use strict';
var React, ChatApp, ChatPanel;

React = require('react');
ChatPanel = require('./chat_panel');

ChatApp = React.createClass({
  render() {
    this.i18n = require('../locales/i18n');
    return (
      <div className="chat-app">
        <h1>{this.i18n.t("app.title")}</h1>
        <ChatPanel />
      </div>
    );
  }
});

module.exports = ChatApp;

As you can see the render() method has a dependency on a local library (i18n), which gets mocked in the test for ChatApp (as I want it to).

But in the test I have no way of overriding the mocked Return Values of the i18n library (which is why it's currently sitting on this. so I could try and access it)

this is the test snippet

'use strict';
var React, ChatApp, TestUtils, path;

path = '../../../scripts/components/';
jest.dontMock( path + 'chat_app');

React = require('react/addons');
ChatApp = require( path + 'chat_app');
TestUtils = React.addons.TestUtils;

describe('ChatApp', () => {
  var ChatAppElement = TestUtils.renderIntoDocument(<ChatApp />);

  it('renders a title on the page', () => {
    ChatApp.i18n.t.mockReturnValue('Chat App');
    var title = TestUtils.findRenderedDOMComponentWithTag(ChatAppElement, 'h1');
    expect(title.props.children).toEqual('Chat App');
  });
});

I can see why it's probably not working as this. in the render method isn't actually putting the i18n object on to the ChatApp object, which is why I can't access it.

This may be the complete wrong way of approaching it too.

I thought perhaps pass it in as a prop, but then when I have nested components the props will be created by the i18n function again so I'll want to mock it again.