How can I test my API created stripe customer properly? - ruby-on-rails

Question

I want to test the API request that creates Stripe customers.
Controller
def create
user = User.create(create_params)
stripe_customer = Stripe::Customer.create({
email: create_params[:email],
name: [create_params[:first_name], create_params[:last_name]].join(' ')
})
user.update(stripe_customer_id: stripe_customer.id)
render(json: { user: user }, status: :ok)
end
private
def create_params
params.permit(
:email,
:first_name,
:last_name
)
end
I saw there is stripe-ruby-mock gem but I am not sure how I can use it?

Answer 1

First of all, you should be able to trust that Stipe's gem will do the right thing when you call it. So, there's no need to test that their create method returns the correct thing. So, all you need to test is that you are calling their API correctly. All you need to do this is an RSpec mock.
Since your code is in a controller, you'll either need to use a controller spec, or you'll need to refactor your code into another class. My preference is the refactor. So, that's what I'll show here.
Controller
Refactored to move business logic into a command class.
def create
user = CreateUser.new(create_params).perform
render(json: { user: user }, status: :ok)
end
CreateUser command class
Refactored a bit to only make one call to the database.
class CreateUser
attr_reader :params
def initialize(params)
#params = params
end
def perform
stripe_customer = Stripe::Customer.create({
email: params[:email],
name: [params[:first_name], params[:last_name]].join(' ')
})
User.create(params.merge(stripe_customer_id: stripe_customer.id))
end
end
Spec file for CreateUser command class
describe CreateUser do
subject(:create_user) { described_class.new(params)
let(:params) do
email: 'some#email.address',
first_name: 'first',
last_name: 'last'
end
describe 'perform' do
let(:stripe_customer_id) { 123 }
before do
allow(Stripe::Customer).to receive(:create).and_return(stripe_customer_id)
allow(User).to receive(:create)
end
it 'creates a Stripe customer' do
create_user.perform
expect(Stripe::Customer).to have_received(:create).with(
email: 'some#email.address',
name: 'first last'
)
end
it 'creates a user with a stripe customer id' do
create_user.perform
expect(User).to have_received(:create).with(
email: 'some#email.address',
first_name: 'first',
last_name: 'last',
stripe_customer_id: 123
)
end
end
end