title: redux dumb component function unit-test
body: <p>I'm quite familiar with smart/dumb components etc. Now I'm doing something like</p>
  
  <p>LoginContainer which connect with redux using react-redux via mapStateToProps and mapDispatchToProps. </p>
  
  <p>Then I have a LoginComponent which has the UI and stuff. </p>
  
  <p>So the question is, when a user click the login button in "LoginComponent", it has to call a function there. So I'm guess the way to do is to pass the function from LoginContainer, and then call it when the button is clicked in LoginComponent?</p>
  
  <p>But in this way, does that mean when doing unit-test, I have to mock the functionality of this button function call in the dumb component LoginComponent?</p>