Testing with Rspec3 controllers with belongs_to association using instance_double - ruby-on-rails

Question

I'm new in testing and learning Rspec, and I can't git it working.
(I have read the book Effective testing with Rspec3, and many tutorials ...also pluralsight.com)
The situation is very simple. In a Companies controller I want to test de Create method, the company model belongs_to user, and is this the code:
I think the problem is when execute
in test: expect(Company).to receive(:new).with(company_params)
or in controller: #company.user=helpers.user
Controller:
class CompaniesController < SessionsController
def create
#company=Company.new(company_params)
#company.user=helpers.user
if #company.save()
redirect_to companies_path
else
render :edit
end
end
and Rspec:
RSpec.describe CompaniesController, type: :controller do
let(:user) { instance_double(User) }
before do
allow_any_instance_of(ApplicationHelper).to receive(:user){user}
allow(controller).to receive(:authorize){true}
end
describe 'Authenticated user with companies' do
let(:company_params) { {company:{name:"Albert",domain:"www.albert.com"}} }
let(:company) { instance_double(Company) }
before do
allow(Company).to receive(:new){company}
end
describe 'POST #create' do
context "with valid data" do
before { allow(company).to receive(:save){true} }
it "redirects to companies_path" do
expect(Company).to receive(:new).with(company_params)
expect(company).to receive(:user=).with(user)
post :create, params:{company: company_params}
expect(response).to redirect_to(companies_path)
end
My intention is very simple: Use instance_double to mock (or stub) #company, and Company.new, using instance double...to test the create action, and simulate the "save()" returning true...etc
I do not know if I explain myself very well, but given the create action of controlloer , how to test using mocks ans stubs, instance_double?
Thanks

Answer 1

First of all let me explain what we need to test here
def create
#company=Company.new(company_params)
#company.user=helpers.user
if #company.save()
redirect_to companies_path
else
render :edit
end
end
We are testing create action of a controller. First let us see what this action does? It's just takes comapany_params as input and create a company record in database.
Testing also goes like the same, we need to just pass the input that action required, and need to check whether it's creating record in database or not.
RSpec.describe CompaniesController, type: :controller do
let(:user) { instance_double(User) }
before do
# all your authentication stubing goes here
allow_any_instance_of(ApplicationHelper).to receive(:user){user}
allow(controller).to receive(:authorize){true}
end
describe 'POST#create' do
context 'with valid attributes' do
before do
post :create, { company:{ name:"Albert", domain:"www.albert.com"} }
end
it 'responds with success' do
expect(response.status).to eq(302)
end
it 'creates company' do
company = Company.find_by(name: "Albert")
expect(assigns(:company)).to eq(company)
expect(response).to redirect_to(companies_path())
end
end
context 'with invalid attributes' do
before do
post :create, { company:{ name:"", domain:""} }
end
it 'renders new template' do
expect(response).to render_template(:edit)
end
end
end
end
No need to sub anything here. As per my knowledge, Only when we use any lib classes / background jobs / third party libraries code inside action then we need to stub those code. Because for all those, we will write specs separately. So no need to test again here that's why we'll do stubing.

Answer 2

Thanks to Narsimha Reddy, I have better ideas about how to test.
Eventhough, if I want to stub
#company=Company.new(company_params)
#company.user=helpers.user
if #company.save()
For testing only de create's response , the solution was in a good use of parameters, and allowing allow(company).to receive(:user=) for the belongs_to association
let(:company_params) {{company:{name:"Albert",domain:"www.albert.com"}}}
let(:ac_company_params) {ActionController::Parameters.new(company_params).require(:company).permit!}
let(:company) { instance_double(Company) }
before do
allow(Company).to receive(:new){company}
allow(company).to receive(:user=)
allow(company).to receive(:save){true}
end
it "redirects to companies_path" do
expect(Company).to receive(:new).with(ac_company_params)
expect(company).to receive(:user=).with(user)
post :create, params: company_params
expect(response).to redirect_to(companies_path)
end