How to Set Session on Rails Request Spec

routes.rb

# frozen_string_literal: true

Rails.application.routes.draw do
  if Rails.env.test?
    namespace :test do
      resource :session, only: :create
    end
  end
end

spec_helper.rb

def set_request_session(variables)
  post test_session_path, params: { variables: variables }
end

test_sessions_controller.rb

# frozen_string_literal: true

module Test
  class SessionsController < ApplicationController
    def create
      variables = params.permit(variables: {})

      variables[:variables].each { |variable, value| session[variable] = value }

      head(:created)
    end
  end
end

test_sessions_create_spec.rb

# frozen_string_literal: true

require "spec_helper"

RSpec.describe Test::SessionsController, type: :request do
  it "sets values on session" do
    post test_session_path, params: { variables: { variable_1: "value_1", variable_2: "value_2" } }

    expect(response).to have_http_status(:created)

    session[:variable_1] = "value_1"
    session[:variable_2] = "value_2"
  end
end