Post request in controller specs - ruby-on-rails

Question

I have problem with testing my controller. I've test post request in 2 context. With valid attributes and with invalid attributes. I have problem with valid attributes context.
I have the following test:
describe "POST #create" do
context "with valid attributes" do
it "saves the new car_configuration in the database" do
expect{
post :create, car_configuration: attributes_for(:car_configuration)
}.to change(CarConfiguration, :count).by(1)
end
it "redirects to the index car_configuration" do
post :create, car_configuration: attributes_for(:car_configuration)
should redirect_to admin_car_configurations_url
end
end
end
And my car_configuration factory is:
FactoryGirl.define do
factory :car_configuration do
sequence(:image) {|n| "Image #{n}"}
small_cases_count 5
big_cases_count 2
association :body_style, factory: :car_body_style
association :model, factory: :car_model
association :car_class
end
end
And errors that rspec shows:
1) Admin::CarConfigurationsController POST #create with valid attributes saves the new car_configuration in the database
Failure/Error: expect{
count should have been changed by 1, but was changed by 0
# ./spec/controllers/admin/car_configurations_controller_spec.rb:42:in `block (4 levels) in <top (required)>'
2) Admin::CarConfigurationsController POST #create with valid attributes redirects to the index car_configuration
Failure/Error: should redirect_to admin_car_configurations_url
Expected response to be a <redirect>, but was <200>
# ./spec/controllers/admin/car_configurations_controller_spec.rb:49:in `block (4 levels) in <top (required)>'

Answer 1

spec/controllers/admin/car_configuratoins_controller_spec.rb
require 'spec_helper'
describe Admin::CarConfigurationsController do
let(:configuration) { build :configuration }
context "POST create" do
it "creates a config" do
expect { perform }.to change(CarConfiguration, :count).by(1)
end
def perform
post :create, car_configuration: configuration.attributes
end
end
end