Authy

Purpose: Authorize a transaction against a persistent datastore.

Simulates a credit card transaction by a merchant against a financial institution.

Includes card and merchant provisioning features, locks to prevent concurrent writes, and a reasonable test suite.

Author: Brian Lucas

Pre-requisites

• Ruby 2.3.0+
• Bundler
• SQLite

Getting started

1. Clone this repo and install dependencies

# bundle install

bundle install
The latest bundler is 1.16.2, but you are currently running 1.15.4.
To update, run `gem install bundler`
Using bundler 1.15.4
Using byebug 10.0.2
Using diff-lcs 1.3
Using rspec-support 3.8.0
Using sequel 5.15.0
Using sqlite3 1.3.13
Using rspec-core 3.8.0
Using rspec-expectations 3.8.2
Using rspec-mocks 3.8.0
Using rspec 3.8.0
Bundle complete! 4 Gemfile dependencies, 10 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

2. Set up the database (via RECREATE_DATABASE=true rspec) or the example.
3. Run tests via rspec. Simulate concurrent tests via rspec & rspec.
4. Try running the example file (ruby authy_example.rb) for a quick primer.

Database

Authy uses Sequel for database functions.

authorize = Authy.new(env: 'default')
authorize.drop_db
authorize.setup_db

You can easily populate a test database by running:

RECREATE_DATABASE=true rspec

authorize = Authy.new(env: 'default')
authorize.drop_db
authorize.setup_db

You can easily populate a test database by running:

RECREATE_DATABASE=true rspec

Environments

Authy uses Dotenv for sane environment configuration defaults. Example:

# .env.test
ENVIRONMENT=test
DEFAULT_CARD_LIMIT=20000
DEFAULT_VELOCITY_LIMIT=1000
LOG_LEVEL=DEBUG

Usage

auth = Authy.new(env: 'default')
success = authy.authorize(<token>, <amount>, <merchant name>)
if success
  puts "Authorization succeeded"
end

Add merchant:

Creates a merchant record for test purposes. Expects an options hash.

Options:
   +name+             - String representing the merchant name

 == Examples:

   Authy.create_merchant(name: 'Philz')

name = "Peets Coffee"
merchant = authy.create_merchant(name: name)

Issue card:

Issues a card for administrative or test purposes. Expects an options hash.

Options:
   +limit+             - Integer representing the card limit in cents ($10.00 = 1000).
   +balance+           - Integer representing the starting balance.
   +velocity_limit+    - Integer representing max amount to spend during velocity_interval
   +velocity_interval+ - Integer representing seconds in the velocity interval
   +token+             - Optional string that can override a random token

Examples:

   card = authy.issue_card(limit: 2000000, balance: 0)
   card = authy.issue_card(token: 'ABCD')

Tests

A full test-suite is available. RECREATE_DATABASE=true rspec

Run rspec from the project root to run all unit and integration tests.

$ rspec
.....D, [2018-12-10T09:49:48.844916 #85049] DEBUG -- : Validating token:
...

Finished in 10.91 seconds (files took 0.32723 seconds to load)
11 examples, 0 failures

To-do's

• Implement a velocity limit and velocity interval as a form of fraud prevention. Set a maxiumum limit that can be authorized in a period of time.