RSpec API controllers testing

Question

At first, sorry for my English :)

I need to realize API controller's tests in Ruby on Rails application (v 4.2.0). When I do request to GET Advertising Sources I have a json response like this:

{"advertising_sources":[{"id":59,"title":"accusantium"},{"id":60,"title":"assumenda"}]} 

JSON response template was defined by front-end developer. Now I trying to create tests for: 1. JSON size (2 advert sources) 2. included attributes (id, title)

My tests:

it 'returns list of advertising sources' do
  expect(response.body).to have_json_size(2)
end

%w(id title).each do |attr|
  it "returns json with #{attr} included" do
    hash_body = JSON.parse(response.body)
    expect(hash_body).to include(attr)
  end
end

Failures:

1. Failure/Error: expect(response.body).to have_json_size(2)
   expected {"advertising_sources":[{"id":59,"title":"accusantium"},{"id":60,"title":"assumenda"}]} to respond to `has_json_size?`

2. Failure/Error: expect(hash_body).to include(attr)

   expected {"advertising_sources" => [{"id" => 71, "title" => "necessitatibus"}, {"id" => 72, "title" => "impedit"}]} to include "id"
   Diff:
   @@ -1,2 +1,2 @@
   -["id"]
   +"advertising_sources" => [{"id"=>71, "title"=>"necessitatibus"}, {"id"=>72, "title"=>"impedit"}],

Can anyone help me to correctify my tests code? Thanks!

Answer 1

Given the shape of your response and the characteristics you are interested in testing, you can write your tests as follows:

describe 'advertising_sources' do
  let(:parsed_response_body) { JSON.parse(response.body) }
  let(:advertising_sources) { parsed_response_body['advertising_sources'] }

  it 'returns list of advertising sources' do
    expect(advertising_sources.size).to eq(2)
  end

  %w(id title).each do |attr|
    it "returns json with #{attr} included" do
      advertising_sources.each { |source| expect(source.keys).to include(attr) }
    end
  end
end

I would personally simplify this even further to:

describe 'advertising_sources' do
  let(:parsed_response_body) { JSON.parse(response.body) }
  let(:advertising_sources) { parsed_response_body['advertising_sources'] }

  it 'returns list of advertising sources' do
    expect(advertising_sources.size).to eq(2)
  end

  it 'includes an id and title for each source' do
    advertising_sources.each { |source| expect(source.keys).to match_array(%w(id title)) }
  end
end