Mastering React Test-Driven Development

Invoking render functions and inspecting their properties

The other routes in App aren't so simple. They require the use of state and props. For example, here's how we rendered AppointmentFormLoader before, which needs to be passed a customer object and an onSave handler:

switch(view) {  case 'addAppointment':    return <AppointmentFormLoader      customer={customer}      onSave={transitionToDayView} />;

To do the same with React Router, we need to use the render prop on a Route:

<Route  path="/addAppointment"  render={() => (    <AppointmentFormLoader      customer={customer}      onSave={transitionToDayView} />  )}/>

This render prop poses a problem. How can we verify that the AppointmentFormLoader was passed the right props?

We need to invoke the render function, but ...