Rspec for conditional code if-else? - ruby-on-rails

Question

I am new to RSpec but here I am trying to create tests based on this code and I am keep on getting this error. Any suggestions?
CODE:
serialization_scope nil
before_action :set_list, only: [:show, :destroy, :update]
before_action :verify_user, only: :show
def create
#list = current_user.lists.build(list_params)
if #list.save
render json: {message: ['Success']}, status: 200
else
render json: {errors:[#list.errors.full_messages]}, status: 400
end
end
Here is the RSpec file that I started :
require "rails_helper"
RSpec.describe V1::ListsController, :type => :controller do
describe "POST create" do
it "returns HTTP status" do
expect(post :create).to change(#list, :count).by(+1)
expect(response).to have_http_status :success #200
end
end
describe 'GET status if its not created' do
it "return HTTP status - reports BAD REQUEST (HTTP status 400)" do
expect(response.status).to eq 400
end
end
end
And the error that I got is :
Failures:
1) V1::ListsController GET status if its created returns HTTP status
Failure/Error: expect(post :create).to change(#list, :count).by(+1)
expected #count to have changed by 1, but was not given a block
# ./spec/controllers/lists_controller_spec.rb:8:in `block (3 levels) in <top (required)>'
2) GET status if its not created return HTTP status - reports BAD REQUEST (HTTP status 400)
Failure/Error: expect(response.status).to eq 400
expected: 400
got: 200
(compared using ==)

Answer 1

Try this code.
require 'rails_helper'
RSpec.describe V1::ListsController, type: :request do
describe 'valid request' do
it 'returns HTTP status' do
post '/list', params: { list: { list_name: 'xyz' } }
expect(response.status).to eq 201
end
end
describe 'invalid request' do
it "should return unauthorized" do
post '/list'
assert_response :unauthorized
end
end
end
In params you need to pass your list_params.

Answer 2

Spec would look like:
describe "POST create" do
context 'valid request' do
it 'should increase #list item' do
expect { post :create }.to change(List, :count).by(1)
end
it "returns HTTP status" do
post :create
expect(response).to have_http_status :success #200
end
end
context 'invalid request' do
it "return HTTP status - reports BAD REQUEST (HTTP status 400)" do
get :create
expect(response.status).to eq 400
end
end
end
Cheers!

Answer 3

You can test an object not being created by intentionally causing some of its validations to fail e.g. you can pass a mandatory attribute as nil from the RSpec.
Sample request: post :create, { title: nil }.
But as per your RSpec code, it seems there are no validations on List model. So, lets try to stub save and return false for this particular test.
describe 'GET status if its not created' do
# Assuming your model name is `List`
before { allow_any_instance_of(List).to receive(:save) { false } }
it "return HTTP status - reports BAD REQUEST (HTTP status 400)" do
post :create
expect(response.status).to eq 400
end
end
Please post your model for list and i can update the answer with more appropriate test.

Answer 4

Ishika, let me see if I can help you :)
RSpec official documentation recommends you to use request specs instead of controller specs. That is recommended because Rails 5 deprecated some methods used on controller testings. You can read more about this here at RSpec blog
ps.: You can use controller tests so far, but it can be deprecated in a future major version of RSpec.
There are some notes I left after the code, please read them also.
I would write a request spec like this:
# spec/requests/v1/lists_controller_create_spec.rb
require "rails_helper"
RSpec.describe V1::ListsController do
describe 'success' do
it 'returns ok and creates a list', :aggregate_failures do # :aggregate_failures is available only for RSpec 3.3+
expect do
post '/list', title: 'foo' # This will also test your route, avoiding routing specs to be necessary
end.to change { List.count }.from(0).to(1)
expect(response).to have_http_status(:ok)
end
end
describe 'bad request' do
before do
# This is needed because your controller is not validating the object, but look at my
# comment below (out of the code), to think about this behavior, please.
allow_any_instance_of(List).to receive(:save).and_return(false)
end
it 'returns a bad request and does not create a list' do
expect do
post '/list', title: 'foo' # This will also test your route, avoiding routing specs to be necessary
end.not_to change { List.count }
expect(response).to have_http_status(:bad_request)
end
end
end
Notes:
I suggested using more than 1 expectation by example, that is ok in this spec because they are simple and because I'm using :aggregate_failures option. With this option, if the first expectation fails, the next expectations will also be executed, considering that in this case, the following expectations does not depend on the first one, it is ok to use more than 1 expectation for the example.Reference
You are returning a bad request if the object is not saved, but you are not validating it. If your model has validations that will validate the object there, please adjust the specs to fail the save (instead of using the mock I used) and consider rendering an error message in the response
If you think that making the post inside a expect block, you can do different: Store the count of Lists in a variable before making the post and after the post you test if the variable has changed or not, maybe you think it will be more clear and it will do exactly the same thing in the background.