Test N+1 in Spec

n1_spec.rb

# Source: https://evilmartians.com/chronicles/squash-n-plus-one-queries-early-with-n-plus-one-control-test-matchers-for-ruby-and-rails
  
# Gemfile
gem 'n_plus_one_control', group: :test

# rails_helper.rb
require 'n_plus_one_control/rspec'

# spec.rb
context 'N+1', :n_plus_one do
  populate { |n| create_list(:reservation_detail, n) }

  specify do
    expect { described_class.new(Date.current, Date.current.next_month).n1 }.to perform_constant_number_of_queries
  end
end