Building observable, testable, even driven Beer bar powered by NodeJS

1. bdd
2. jsdoc for comments

bar should be named bar has seating capacity (queue) bar has a bartender bar has waiting queue bar maintain count of successfully served customer and count of loss customers

customer each customer first waits in bar waiting queue if the queue is full, the customer cannot join and considered as lost count for the bar customer has to be seated first before ordering drink each customer can drink between 1 - 10 drinks it takes between 100 to 500 ms to drink one drink customer pays bill before leaving the seat

bar tender moves customer from waiting queue to seating queue serves drinks handle payment

bar events

newCustomer (customer generator produces this event) -> adds the customer to waiting queue / increase the lost count for bar produces waitOnQueue on customer

ExitFromSeat removes customer from seat or from seating increments success count try to seat next person waiting on queue

ExitFromWaitQ removes customer from waitQ or from seating

LoseCustomer increments bar loss count removes customer from the waitQ

bar tender events

waitingOnQueue try to add customer to seating queue if successful produces exit-from-waitq event on bar produces seated event on customer if unsuccessful do nothing orderDrinks produces drinkServed event on customer handleCheck removes customer from seated queue

customer events

waitOnQueue (bar produces this event) updates customer status to 'waiting' sets up wait timeout produces waitingOnQueue on bar tender

seated (bar tender produces this event) sets customer status to 'seated' clearTimeout wait timeout produces orderDrinks on bar tender drinkServed (bar tender produces this event) waits between 100 to 500 ms if more drinks needed produces orderDrinks on bar tender else produces handleCheck on bar tender

Bar

listens: ['new-customer'] produces: [{ctx: Customer, events: ['wait-on-queue']}]

Customer

listens: ['wait-on-queue', 'seated', 'drink-served'] produces: [{ctx: Bartender, events: ['waiting-on-queue', 'order-drinks', 'handle-check']}]

Bartender

listens: ['waiting-on-queue', 'order-drinks', 'handle-check'] produces: [{ctx: Customer, events: ['wait-on-queue', 'seated', 'drink-served']}]

lets assume there is no bartender, add a bartender and seating later make bar singleton bar.getInstance track total number of customers served implement eventcollector track total number of beers served add price for beer track total revenue bar open since time lot

make map out of customer name from current seated customer make different parts of template and combine it together waiting queue view