rspec test fails to enable javascript - ruby-on-rails

Question

I have the next test with rspec and selenium:
require 'rails_helper'
feature "Creating an student" do
context "When an student visit the sign_up page" do
scenario "Should be able to create an student" do
state = FactoryGirl.create(:state)
city = FactoryGirl.create(:city, state: state)
institution = FactoryGirl.create(:institution)
visit root_path
.........
The devise function to register is this:
def new
#institutions = Institution.all.order(:name)
#states = State.all
#cities = City.all
super
end
when I search in my controller the States and Cities, I found this, but when I enable javascript
scenario "Should be able to create an student", js: true do
the States and Cities return nil.
Update 1
My spec_helper file is this:
require 'database_cleaner'
require 'capybara'
Capybara.register_driver :chrome do |app|
Capybara::Selenium::Driver.new(app, :browser => :chrome)
end
Capybara.javascript_driver = :chrome
Capybara.default_max_wait_time = 10
RSpec.configure do |config|
config.before(:suite) do
DatabaseCleaner.clean_with(:truncation)
DatabaseCleaner.strategy = :transaction
end⋅
config.before(:each) do
DatabaseCleaner.start
end⋅
config.after(:each) do
DatabaseCleaner.clean
end⋅
end
I do not know why this happens.