Request in Rails Testing not returning body - ruby-on-rails

Question

I'm starting to do some testing to my app in rails, and following official tutorial, I've written this:
class UserFlowTest < ActionDispatch::IntegrationTest
def login
post ns_login_user_path, { :user => { :username => 'user', :password => 'password' } }
assert_response 200
end
test "should complete a flow" do
login
post create_participant_path(:event_id => events(:myevent).id), {
:format => :json,
:event_role => event_roles(:regular_participant).id,
:in_team => true
}
r = JSON.parse(response.body)
assert_response 200
puts "response creating participation #{r.as_json}"
participant_id = r[:participant_id]
end
end
It does the login OK, but after that, when trying to create the participant, response is a variable with no .body attribute, just the number 200 (the status), so the JSON.parse method crashes.
This is the relevant part of my routes.rb:
# Events
scope 'events', :controller => :events do
# some routes
scope ':event_id', :controller => :events do
# some routes
scope 'participants', :controller => :participants do
post '', :action => :create_participant, :as => :create_participant
# some routes
end
end
end
And the controller ParticipantsController.rb:
class ParticipantsController < ApiController
before_action :require_login, :only => [:create_participant, :update_participant]
# Creates a participation of a person in the event
# Receives the following params:
# - +event_id+
# - +in_team+::_boolean
# - +event_role+
def create_participant
# … some logic
if participant.save
render :status => :ok, :json => Hash[
:participant_id => participant.id,
:team_participant_id => participant.team_participant_id
]
else
render :status => 406, :json => Hash[
:message => t('alerts.error_saving'),
:errors => participant.errors.as_json
]
end
end
end

Answer 1

I've seen the full response object on controller specs, but looking at the code, it appears that the ActionDispatch::IntegrationTest code only returns the response.status, not the entire response object.
The documentation doesn't directly say that you can access the response object. You might try doing a render_views and see if that makes any difference, but based on inspection of the code, it doesn't seem like it will.