# Terminal
rails test

# test/controllers/purchases_controller_test.rb
require 'test_helper'

class PurchasesControllerTest < ActionDispatch::IntegrationTest
  setup do
    sign_in users(:user_one)
    @product = products(:tenvbucks)
  end

  test "should create purchase" do
    post purchases_url, params: { product_id: @product.id, format: :js }
    assert_response :success
  end
end

# test/fixtures/products.yml
tenvbucks:
  name: 10 vbucks
  price: 9.99
  quantity: 10

# test/fixtures/users.yml
user_one:
  first_name: John
  last_name: Doe
  email: [email protected]
  encrypted_password: <%= User.new.send(:password_digest, '123456') %>

# test/test_helper.rb
ENV['RAILS_ENV'] ||= 'test'
require_relative '../config/environment'
require 'rails/test_help'

class ActiveSupport::TestCase
  # Run tests in parallel with specified workers
  parallelize(workers: :number_of_processors)

  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
  fixtures :all

  # Add more helper methods to be used by all tests here...
  include Devise::Test::IntegrationHelpers
  include Warden::Test::Helpers
end

# test/models/payment_received_test.rb
require 'test_helper'

class PaymentReceivedTest < ActiveSupport::TestCase
  setup do
    @user = users(:user_one)
    json = {
      data: {
        object: {
          id: 'test',
          amount_subtotal: 999,
          amount_total: 999,
          client_reference_id: @user.id,
          customer: 'test_stripe_id'
        }
      }
    }.to_json
    @payment = JSON.parse(json, object_class: OpenStruct)
  end

  test "should credit user vbucks" do
    assert_equal @user.vbuck.to_i, 0
    payment_received = PaymentReceivedMock.call(@payment)
    @user.reload
    assert_equal @user.stripe_id, 'test_stripe_id'
    assert payment_received
    assert_equal @user.vbuck, 20
  end
end

class PaymentReceivedMock < PaymentReceived
  private
  def line_items
    [
      OpenStruct.new(description: '10 vbucks', quantity: 1),
      OpenStruct.new(description: '10 vbucks', quantity: 1)
    ]
  end
end

# app/models/payment_received.rb
...

  def call
    return false unless user
    user.update(stripe_id: object.customer) unless user.stripe_id
    complete_purchase
    true
  end

...