app.js

const root = <Relay.RootContainer
  Component={TodoApp}
  route={new ViewerRoute()}
  renderFetched={(data) => {
    return (
      <TodoApp
        {...data}
      />
    )
  }}
  renderLoading={() => <div>Loading</div>}
  renderFailure={(error) => <div>{error}</div>}
/>
ReactDOM.render(
  root,
  document.getElementById('root')
)