SQL Queries Summaries helper

sql_query_countiner.rb

module SqlQueryCountingHelpers
  # This helper can be used to instrument a segment of test code to analyze the
  # SQL queries being executed for that portion of the code path.
  #
  # It's intended to be used around specific portions of a spec rather than an
  # entire spec as the FactoryBot usage adds a good amount of noise to the SQL
  # analysis due to the many objects & associations created.
  #
  # Usage example (using spec/requests/api/v1/projects_spec.rb):
  #
  # ``` rb
  # with_sql_count do
  #   get '/api/v1/projects', headers: auth_headers(user)
  # end
  # ```
  #
  # which will produce output like:
  #
  #     Get /api/v1/projects
  #     User Load
  #     User Load
  #
  #     Project Load
  #     Project Load
  #     Area Load
  #     SharedImage Load
  #     Action Load
  #     SCHEMA
  #     DailyReminder Load
  #     SCHEMA
  #     SCHEMA
  #     ==================================================
  #     There were 14 SQL calls
  #     --------------------------------------------------
  #
  # You can then tweak the implementation and see how the structure and count of
  # SQL queries changes
  def with_sql_count(&block)
    sql_count = 0
    callback = ->(*args) do
      event = ActiveSupport::Notifications::Event.new *args
      puts event.payload[:name].presence || event.payload[:sql].first(50)
      sql_count +=1
    end
    ActiveSupport::Notifications.subscribed(callback, "sql.active_record") do
      yield
    end

    puts <<~EOM
      #{'='*50}
      There were #{sql_count} SQL calls
      #{'-'*50}
    EOM
  end
end

RSpec.configure { |config| config.include SqlQueryCountingHelpers }