The scope of the app is to query two endpoints (users and purchases) and with with the data retrieved allow the user to know the most sold item, the most loyal user and the total spend of a specific user.

1. Faraday HTTP/REST API client library.
2. Rspec BDD for Ruby
3. Vcr Record your test suite's HTTP interactions and replay them during future test runs for fast, deterministic, accurate tests.
4. email_address The EmailAddress Gem to work with and validate email addresses.

install the dependency: bundle install then ruby app.rb most_sold to get the most sold item ruby app.rb total_spend [EMAIL]to get the total spend of a user ruby app.rb most_loyal to get the email of the most loyal user (most purchases)

or require the file driftlock.rb in another ruby script to have access to the sam function in a programmatic way

ruby app.rb most_sold total_spend [EMAIL]to get the total spend of a user most_loyal to get the email of the most loyal user (most purchases)

Driftrock.most_sold will return a string with the name of the most sold item (in a real world application I would return the product object) Driftrock.total_spend([EMAIL]) will return a float number with the total spent from the user Driftrock.most_loyal will return a user object of the userwith the most purchases

the app will raise a this exception: Malformed command if a parameter is passed to commands that dont need it (most_sold, most_loyal) Missing argument if the email parameter is not passed to the most_loyal command Unrecognized command if the command cannot be recognized

Malfomed Hash if the monkey patched method top_element is used on an hash not composed of only array as values

Attribute not available if an unavailable attribute is passed to the all_by method

Malformed Email Address if the email address for the find_by_email function is invalid User not found if a user is not found in the methods find and find_by_email