The restaurant has two tables: one with 2 seats, and one with 4 seats. The tables cannot be combined The restaurant is open from 5pm-10pm Monday through Friday. All reservations are two hours long without exception. No longer, no shorter. A user can come to the site and request a reservation. They will indicate the name, the date, the time, and the number of people in the party. If a table is available, reserve it. Show the error otherwise.
Example of Test-Driven-Development using Ruby on Rails & RSpec