Test script for the Decidim surveys memory leak

decidim_survey_test.rake

# frozen_string_literal: true

namespace :decidim do
  namespace :surveys do
    task test_memory_leak: :environment do
      unless Rails.env.test?
        puts %(Please run this with "RAILS_ENV=test")
        next
      end

      puts "Cleaning the test database..."
      Rake::Task["db:schema:load"].invoke

      puts ""
      puts "== Starting memory leak test"
      puts "Creating the necessary structure for the test..."
      organization = Decidim::Organization.create!(
        name: "Memory leak test",
        host: "memoryleak.lvh.me",
        external_domain_whitelist: ["decidim.org", "github.com"],
        description: { en: "<p>Test for memory leak.</p>" },
        default_locale: "en",
        available_locales: ["en"],
        reference_prefix: "MEMLEAK",
        available_authorizations: [],
        users_registration_mode: :enabled,
        tos_version: Time.current,
        badges_enabled: true,
        user_groups_enabled: true,
        send_welcome_notification: true,
        file_upload_settings: Decidim::OrganizationSettings.default(:upload)
      )
      participatory_space = Decidim::ParticipatoryProcess.create!(
        title: { en: "Memory leak" },
        slug: "memleak",
        subtitle: { en: "Test for memory leak" },
        short_description: { en: "<p>Test for memory leak.</p>" },
        description: { en: "<p>Test for memory leak.</p>" },
        organization:,
        published_at: Time.current,
        start_date: Date.current,
        end_date: 2.months.from_now
      )
      component = Decidim::Component.create!(
        name: { en: "Survey" },
        manifest_name: :surveys,
        published_at: Time.current,
        participatory_space:
      )
      survey = Decidim::Surveys::Survey.new(component:)
      questionnaire = Decidim::Forms::Questionnaire.create!(
        title: { en: "Test survey" },
        description: { en: "<p>#{"a" * 1_000_000}</p>" },
        tos: { en: "<p>You need to accept testing.</p>" },
        questionnaire_for: survey
      )
      question = Decidim::Forms::Question.create!(
        questionnaire:,
        position: 0,
        body: { en: "Answer this question" },
        question_type: "short_answer"
      )

      puts "Creating 3000 answers (this may take a while, please wait)..."
      3000.times do |num|
        Decidim::Forms::Answer.create!(
          questionnaire:,
          question:,
          body: "Answer from user #{num}",
          session_token: "token-#{num}",
          ip_hash: "xyz"
        )
      end

      puts "Serializing the answer sets..."
      all_answers = Decidim::Forms::QuestionnaireUserAnswers.for(questionnaire)

      initial_memory = memory_usage
      all_answers.each_with_index do |answer_set, idx|
        puts "Memory usage (#{idx}): #{memory_usage}" if (idx % 100).zero?
        Decidim::Forms::UserAnswersSerializer.new(answer_set).serialize
      end
      puts "Memory usage (end): #{memory_usage}"
      puts "Diff: #{memory_usage - initial_memory}"

      puts "Cleaning the test database..."
      Rake::Task["db:schema:load"].invoke
    end

    def memory_usage
      `ps -o rss #{Process.pid}`.lines.last.to_i
    end
  end
end