Vending Machine

SketchSystems.spec

Vending Machine
 OrderProcessStarted
 
 WaitingForMoney*
   insert coin -> validating coin
   select product -> validating selection
   request return coins -> returning coins
 
 validating coin
   valid -> WaitingForMoney
   invalid -> Returning Coin

 validating selection
   product available? -> validating price
   product not available? -> WaitingForMoney
   
 validating price
   exact coins? -> dispensing product
   too many coins? -> returning change
   not enough coins? -> WaitingForMoney
   
 Returning Coin
   return coin -> WaitingForMoney
   
 returning change
   return coin -> dispensing product
   
 returning coins
   returning all coins -> WaitingForMoney
   
 dispensing product
   dispense -> WaitingForMoney

SketchSystems_prototype.js

function render(model){
  let current_state_name = model.active_states[0].name;
  return $("h1",
           {style: {color: "darkBlue"}},
           `The current state is: ${current_state_name}`);
}