Let's build a Food Delivery program for a restaurant.

The software will run in one restaurant only, so no need to think of a multi-restaurant one (no need for a Restaurant model for instance).

The main components are:

• Employees (managers, delivery guys)
• Customers of the Restaurant
• Meals that can be ordered
• Orders made by customers, and assigned to a given delivery guy.

1 - (Meal) What's on the menu?

Your restaurant sells food, so you must store somewhere the meals that can be ordered. A meal typically has a name and a price. Write some code to model this, along with the repository which will read/write the meals from a CSV.

Then let's move to the controller. Here are the user actions we want to implement:

• List all meals available in the restaurant
• Add a new meal (later, we'll restrict that to the manager role)

The rake should help you go through all these steps. Follow your guide!

To launch only meal tests, use rspec -t meal

Done? Good! Time to commit and push.

2 - We need a router!

We haven't launch our app code yet. We need a router and a run method. Go back to the Cookbook code to get some inspiration. Make sure that you can run the two meals-related user actions when launching the program:

ruby app.rb

Done? Good! Time to commit and push.

3 - (Customer) Who's always right?

We will maintain a list of all our customers. When a new customer calls to order, we'll first need to add him/her to our list. A customer has a name and an address. Work on the model, the repository to store the CSV (it's a different file than meals.csv!) and finally the controller to implement the following user actions:

• List all customers available in the restaurant
• Add a new customer (later, we'll restrict that to the manager role as well)

Once your controller methods are implemented, add them to the router! Make sure your 4 user actions work before moving on to the next feature.

ruby app.rb

To launch only customer tests, use rspec -t customer

Done? Good! Time to commit and push.

4 - (Optional) Inheritance to the rescue

When you look at MealRepository and CustomerRepository, don't you see similarities? We want to stay DRY, so time to introduce a parent class, BaseRepository, which will hold the common behavior.

Reminder: as it's an optional section, you can skip it and come back to it later.

5 - (Employee) Who's working here?

The restaurant has two types of employees, managers and delivery guys. We want to implement a read-only logic for EmployeeRepository from a CSV file that we fill manually (no need for an add action).

Open your employees.csv file and manually add some employees:

id,username,password,role
1,paul,secret,manager
2,john,secret,delivery_guy

With that information, we can implement a login logic in our app to have two menus in the router depending on the user role: a menu for the manager, and a menu for the delivery guy (with less user actions available).

To handle that, we'll introduce a notion of session. At the router level, we'll store the logged in user in a session.

The sign sequence should go like this:

> username?
paul
> password?
blablabla
Wrong credentials... Try again!
> username?
paul
> password?
secret
Welcome paul!

Now when you run the food delivery app, the first thing you can do is to sign in, and then the menu printed to you should be dependent on your role:

ruby app.rb

To launch only employee tests, use rspec -t employee

Done? Good! Time to commit and push.

Optional: Their password would be stored in clear in the CSV / display in clear, is that a good idea? What could we do?

6 - (Order) Time to link all the models!

An order is taken for a given customer, a given meal (we'll simplify to say that an order is just one meal) and assigned to a given delivery guy. Moreover, the Order model should store the info that it has been delivered (or not).

That's where our models become connected together. Write the Order model class and its repository.

Then, make sure that the following user stories are implemented in your program:

• As an employee, I can log in
• As a manager, I can add a meal
• As a manager, I can view all the meals
• As a manager, I can add a customer
• As a manager, I can view all the customers
• As a manager, I can view all the undelivered orders
• As a manager, I can add an order for a customer and assign it to a delivery guy
• As a delivery guy, I can view my undelivered orders
• As a delivery guy, I can mark an order as delivered

To launch only order tests, use rspec -t _order

7 - (Optional) - Destroy actions

We did not talk about deleting stuff here. What happens if you want to implement these new user stories?

• As a manager, I can delete a meal
• As a manager, I can delete a customer