hopkinsd / take_home

The Solution

I've implemented a solution that uses Ruby, Sequel (gem) and Sqlite3.

Setup

I recommend using RVM with gemsets (even though I had an issue with RVM/Bundler/something not using what it should have; generally it is pretty seamless to use).

Some systems may need to prefix rake and bin commands with bundle exec.

The project uses bundler so setup should be as simple as:

gem install bundler
bundle install
rake db:migrate

You can open up a console:

bin/console

and add a few products

(1..4).map do |num|
  Product.create title: "product #{num}", available_inventory: 10 * num, price: 20.02 * num
end

Usage

The main entry point for the api is bin/api and takes two command line parameters: the action and a json param string. Errors are printed to STDERR and response json is printed to STDOUT. A nonzero exit status code means the request has an error.

Here are the possible actions with required json keys and STDOUT responses:

• add
  • requires: user_id, product_id, quantity
  • prints json of current cart
  • example: bin/api add '{"user_id": 1, "product_id": 1, "quantity": 1}'
• remove
  • requires: user_id, product_id
  • prints json of current cart
  • example: bin/api remove '{"user_id": 1, "product_id": 1}'
• cart
  • requires: user_id
  • prints json of current cart
  • example: bin/api cart '{"user_id": 1}'
• purchase
  • requires: user_id
  • nothing printed to STDOUT
  • example: bin/api purchase '{"user_id": 1}'
• history
  • requires: user_id
  • prints json hash of past purchases, keyed by date
  • example: bin/api history '{"user_id": 1}'

More

Developed with RVM and Ruby 2.4.1

Please let me know if you have any questions.