RSpec sending raw JSON parameters post request - ruby-on-rails

Question

So I'm trying to test a post request in order to save some book details. The response comes as raw JSON due to its being stringified in the client using formData. So that I can format the response appropriately in the controller.
I cannot find any clear way to send raw JSON parameters as rails automatically coerce these parameters as a HASH. Any suggestion?
Rails 5.1.4
Rspec 3.7.2
books_spec.rb
# Test suite for POST /books
describe 'POST /books' do
# valid payload
let(:valid_attributes) do
# send stringify json payload
{
"title": "Learn Elm",
"description": "Some good",
"price": 10.20,
"released_on": Time.now,
"user_id": user.id,
"image": "example.jpg"
}.to_json
end
# no implicit conversion of ActiveSupport::HashWithIndifferentAccess into String
context 'when the request is valid' do
before { post '/books', params: valid_attributes, headers: headers }
it 'creates a books' do
expect(json['book']['title']).to eq('Learn Elm')
end
it 'returns status code 201' do
expect(response).to have_http_status(201)
end
end
context 'when the request is invalid' do
let(:valid_attributes) { { title: nil, description: nil }.to_json }
before { post '/books', params: valid_attributes, headers: headers }
it 'returns status code 422' do
expect(response).to have_http_status(422)
end
it 'returns a validation failure message' do
expect(response.body)
.to match(/Validation failed: Title can't be blank, Description can't be blank/)
end
end
end
books_controller.rb
# POST /books
def create
#book = current_user.books.create!(book_params)
render json: #book, status: :created
end
def book_params
binding.pry # request.params[:book] = HASH
parsed = JSON.parse(request.params[:book])
params = ActionController::Parameters.new(parsed)
params['image'] = request.params[:image]
params.permit(
:title,
:description,
:image,
:price,
:released_on,
:user
)
end

Answer 1

#you should try test the request first like this and if you see this helping you I will send you the 200 test
describe "#create" do
context "when the request format is not json" do
let(:error_message) do
{ "Invalid Request Format" => "Request format should be json" }
end
before do
post :create, headers: { "CONTENT_TYPE": "XML" }
end
it "should return a status of 400" do
expect(response).to have_http_status(400)
end
it "should return an invalid request format in the body" do
expect(json(response.body)).to eql error_message
end
end
end