what exactly is this rspec stub :where and what does it do? - ruby-on-rails

I am looking through some tests written by other people and i keep seeing ':where' in their tests. I guess its a stub, but just finding my feet with testing and want to know is it any different from a normal stubs, what does the naming imply?
describe "delete destroy" do
context "is not allowed by user" do
before do
allow(model).to receive(:where).and_return(no_instances)
allow(no_instances).to receive(:first).and_return(no_instances)
end
context "where the record is destroyed" do
before do
allow(instance).to receive(:destroy).and_return(true)
delete :destroy, params_id
end
sets_flash(:notice)
redirects_to('/airbrake_accounts')
end
context "where the record is not destroyed" do
before do
allow(instance).to receive(:destroy).and_return(false)
delete :destroy, params_id
end
sets_flash(:error)
redirects_to('/airbrake_accounts')
end
end
context "where the record is not found" do
before do
allow(model).to receive(:where).and_return(no_instances)
delete :destroy, params_id
end
sets_flash(:error)
redirects_to('/airbrake_accounts')
end
end
I can see what is going on here (I think), things like ':new' are controller actions right?
describe "photo create" do
before do
allow(model).to receive(:new).and_return(instance)
end
context "where all is not well" do
before do
allow(instance).to receive(:save).and_return(false)
post :create, params_new_instance
end
sets_flash(:error)
it "should render the new form" do
expect(response).to render_template("entries/new")
end
end
context "where all is well" do
before do
allow(instance).to receive(:save).and_return(true)
post :create, params_new_photo
end
sets_flash(:notice)
redirects_to ('/photos')
end
end

They are class or instance methods on the model. Lets just say that the model variable in your example is set to the Dog model and this is testing the DogController.
# model
class Dog
def where(params)
do_stuff
end
end
# controller
class DogController > ApplicationController
def destroy
#dogs = Dog.where(id: 1)
redirect :new
end
end
Now I want to test whats going on in my controller, but I don't want to test anything that my model actually does. I'm isolating a unit of my code to be tested. This is different than testing how it all works integrated together (google unit testing or integration testing).
In order to test just whats going on in my controller I stub the methods happening on my model to keep things isolated and clean. The way I do this is by stubbing it out in my controller spec. So In my DogControllerSpec I do:
before do
allow(Dog).to receive(:where).and_return([])
end
So I'm saying allow my dog class to receive the 'where' method call, but don't execute its logic, and instead return me an empty array.
Then I can setup up the code I'm actually testing which is that my destroy method renders new when called.
it "should render the new form" do
expect(response).to render_template("dogs/new")
end
The key here is really that you are attempting to decouple your tests, so that when you unit test your DogController#destroy you are not testing your Dog.where method. The reasoning being that if you change code in your Dog model it should not break specs in your DogControllerSpec.

They are using symbol #to_proc, I believe, to 'stub' calling the method #where on model. So that means the line:
allow(model).to receive(:where).and_return(no_instances)
is essentially
model.where #=> [].
:new is a controller action, but the way this code is using it is more like SomeClass.new, i.e. the method to create an instance of a class(which is the model).

Related

How to test that a class is called in a controller method with RSpec

I am testing my controller to ensure that a library class is called and that the functionality works as expected. NB: This might have been asked somewhere else but I need help with my specific problem. I would also love pointers on how best to test for this.
To better explain my problem I will provide context through code.
I have a class in my /Lib folder that does an emission of events(don't mind if you don't understand what that means). The class looks something like this:
class ChangeEmitter < Emitter
def initialize(user, role, ...)
#role = role
#user = user
...
end
def emit(type)
case type
when CREATE
payload = "some payload"
when UPDATE
payload = "some payload"
...
end
send_event(payload, current_user, ...)
end
end
Here is how I am using it in my controller:
class UsersController < ApplicationController
def create
#user = User.new(user_params[:user])
if #user.save
render :json => {:success => true, ...}
else
render :json => {:success => false, ...}
end
ChangeEmitter.new(#user, #user.role, ...).emit(ENUMS::CREATE)
end
end
Sorry if some code doesn't make sense, I am trying to explain the problem without exposing too much code.
Here is what I have tried for my tests:
describe UsersController do
before { set_up_authentication }
describe 'POST #create' do
it "calls the emitter" do
user_params = FactoryGirl.attributes_for(:user)
post :create, user: user_params
expect(response.status).to eq(200)
// Here is the test for the emitter
expect(ChangeEmitter).to receive(:new)
end
end
end
I expect the ChangeEmitter class to receive new since it is called immediately the create action is executed.
Instead, here is the error I get:
(ChangeEmitter (class)).new(*(any args))
expected: 1 time with any arguments
received: 0 times with any arguments
What am I missing in the above code and why is the class not receiving new. Is there a better way to test the above functionality? Note that this is Rspec. Your help will be much appreciated. Thanks.
You need to put your expect(ChangeEmitter).to receive(:new) code above the post request. When you are expecting a class to receive a method your "expect" statement goes before the call to the controller. It is expecting something to happen in the future. So your test should look something like:
it "calls the emitter" do
user_params = FactoryGirl.attributes_for(:user)
expect(ChangeEmitter).to receive(:new)
post :create, user: user_params
expect(response.status).to eq(200)
end
EDIT
After noticing that you chain the "emit" action after your call to "new" I realized I needed to update my answer for your specific use case. You need to return an object (I usually return a spy or a double) that emit can be called on. For more information on the difference between spies and doubles check out:
https://www.ombulabs.com/blog/rspec/ruby/spy-vs-double-vs-instance-double.html
Basically a spy will accept any method called on it and return itself whereas with a double you have to specify what methods it can accept and what is returned. For your case I think a spy works.
So you want to do this like:
it "calls the emitter" do
user_params = FactoryGirl.attributes_for(:user)
emitter = spy(ChangeEmitter)
expect(ChangeEmitter).to receive(:new).and_return(emitter)
post :create, user: user_params
expect(response.status).to eq(200)
end

How to call the create action from the controller in RSpec

I have a controller create action that creates a new blog post, and runs an additional method if the post saves successfully.
I have a separate factory girl file with the params for the post I want to make. FactoryGirl.create calls the ruby create method, not the create action in my controller.
How can I call the create action from the controller in my RSpec? And how would I send it the params in my factory girl factories.rb file?
posts_controller.rb
def create
#post = Post.new(params[:post])
if #post.save
#post.my_special_method
redirect_to root_path
else
redirect_to new_path
end
end
spec/requests/post_pages_spec.rb
it "should successfully run my special method" do
#post = FactoryGirl.create(:post)
#post.user.different_models.count.should == 1
end
post.rb
def my_special_method
user = self.user
special_post = Post.where("group_id IN (?) AND user_id IN (?)", 1, user.id)
if special_post.count == 10
DifferentModel.create(user_id: user.id, foo_id: foobar.id)
end
end
end
Request specs are integration tests, using something like Capybara to visit pages as a user might and perform actions. You wouldn't test a create action from a request spec at all. You'd visit the new item path, fill in the form, hit the Submit button, and then confirm that an object was created. Take a look at the Railscast on request specs for a great example.
If you want to test the create action, use a controller spec. Incorporating FactoryGirl, that would look like this:
it "creates a post" do
post_attributes = FactoryGirl.attributes_for(:post)
post :create, post: post_attributes
response.should redirect_to(root_path)
Post.last.some_attribute.should == post_attributes[:some_attribute]
# more lines like above, or just remove `:id` from
# `Post.last.attributes` and compare the hashes.
end
it "displays new on create failure" do
post :create, post: { some_attribute: "some value that doesn't save" }
response.should redirect_to(new_post_path)
flash[:error].should include("some error message")
end
These are the only tests you really need related to creation. In your specific example, I'd add a third test (again, controller test) to ensure that the appropriate DifferentModel record is created.

Set current_user in test

I have a test that looks like this:
test "should get create" do
current_user = FactoryGirl.build(:user, email: 'not_saved_email#example.com')
assert_difference('Inquiry.count') do
post :create, FactoryGirl.build(:inquiry)
end
assert_not_nil assigns(:inquiry)
assert_response :redirect
end
That's testing this part of the controller:
def create
#inquiry = Inquiry.new(params[:inquiry])
#inquiry.user_id = current_user.id
if #inquiry.save
flash[:success] = "Inquiry Saved"
redirect_to root_path
else
render 'new'
end
end
and the factory:
FactoryGirl.define do
factory :inquiry do
product_id 2
description 'I have a question about....'
end
end
but I keep getting errors in my tests:
1) Error:
test_should_get_create(InquiriesControllerTest):
RuntimeError: Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id
What am I doing wrong? I need to set the current_user, and I believe I am in the test, but obviously, that's not working.
You didn't create current_user. It was initialized only in test block.
There are two differents ways to do it:
First, use devise test helpers. Something like that
let(:curr_user) { FactoryGirl.create(:user, ...attrs...) }
sign_in curr_user
devise doc
Second, you can stub current_user method in your controllers for test env
controller.stub(current_user: FactroryGirl.create(:user, ...attrs...))
And you should use FactoryGirld.create(...) instead of FactoryGirl.build(...), because you factory objects have to be persisted.(be saved in db and has id attribute not nil)
There are several things which come to mind:
FactoryGirl.build(:user, ...) returns unsaved instance of a user. I'd suggest to use Factory.create instead of it, because with unsaved instance there's no id and there's no way for (usually session based) current_user getter to load it from database. If you're using Devise, you should "sign in" user after creating it. This includes saving record in DB and putting reference to it into session. See devise wiki
Also, passing ActiveRecord object to create action like this looks weird to me:
post :create, FactoryGirl.build(:inquiry)
Maybe there's some rails magic in play which recognizes your intent, but I'd suggest doing it explicitly:
post :create, :inquiry => FactoryGirl.build(:inquiry).attributes
or better yet, decouple it from factory (DRY and aesthetic principles in test code differ from application code):
post :create, :inquiry => {product_id: '2', description: 'I have a question about....'}
This references product with id = 2, unless your DB doesn't have FK reference constraints, product instance may need to be present in DB before action fires.

Ruby On Rails Function Testing :index with a polymorphic model

I have a polymorphic model called Address, I am trying to currently write some basic function tests for this model and controller. For the controller I am at a loss on how to go about this. For example I have another model called Patient, each Patient will have an address, so i have started writing the following function test, but i have no idea how to use "get" with a nested polymorphic resource. Now I was able to find some polymorphic test information on Fixtures here: http://api.rubyonrails.org/classes/Fixtures.html
but this will not help me test against the index. Any help is much appreciated im at a total and complete loss here.
FILE: test/functional/addresses_controller_test.rb
require 'test_helper'
class AddressesControllerTest < ActionController::TestCase
setup do
#address = addresses(:of_patient)
#patient = patients(:one)
activate_authlogic
end
test "patient addresses index without user" do
get :index <<<<<<<<<<<< what goes here????
assert_redirected_to :login
end
end
Assuming your controller is setup the way I think it might be:
def index
if #current_user
#addresses = #current_user.addresses.all
else
redirect_to login_path
end
end
Then the test will probably look like this:
test "patient addresses index without user" do
get :index, :patient_id => #patient.id
assert_redirected_to :login
end
test "patient addresses with user" do
#current_user = #patient
get :index, :patient_id => #patient.id
assert_response :success
end
The thing to keep in mind is that the index method needs the patient_id to process.

How to spec controller where model associations occur

I'm trying to spec the controller code:
# ClustersController
def create
# create new cluster
#cluster.user = current_user
# save code
end
I am using Rails 3 / RSpec 2 and I'm fairly new to the TDD flow. I basically want to make sure that the user attribute is assigned during the create action.
To begin with i don't think you should create, update an save the object. You can pass the user to the create method, like this:
Cluster.create(:user => current_user)
And to test this you can do:
describe ClusterController do
describe "POST create" do
it "creates a new cluster" do
lamda do
post :create
end.should change(Cluster, :count).by(1)
end
it "set the current user as the new cluster's user" do
user = mock()
Cluster.should_receive(:create).with(:user => user)
post :create
assign(:cluster).user.should == user
end
end
end
I think that will do.
Hope that help.

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