# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Gitlab::RepositoryCache::Preloader, :use_clean_rails_redis_caching,
                                                   feature_category: :source_code_management do
  let(:projects) { create_list(:project, 2, :repository) }
  let(:repositories) { projects.map(&:repository) }
  let(:cache) { Gitlab::RepositoryCache.store }

  describe '#preload' do
    context 'when the values are already cached' do
      before do
        # Warm the cache but use a different model so they are not memoized
        repos = Project.id_in(projects).order(:id).map(&:repository)

        allow(repos[0].head_tree).to receive(:readme_path).and_return('README.txt')
        allow(repos[1].head_tree).to receive(:readme_path).and_return('README.md')

        repos.map(&:exists?)
        repos.map(&:readme_path)
      end

      it 'prevents individual cache reads for cached methods' do
        expect(cache).to receive(:read_multi).once.and_call_original

        described_class.new(repositories).preload(
          %i[exists? readme_path]
        )

        expect(cache).not_to receive(:read)
        expect(cache).not_to receive(:write)

        expect(repositories[0].exists?).to eq(true)
        expect(repositories[0].readme_path).to eq('README.txt')

        expect(repositories[1].exists?).to eq(true)
        expect(repositories[1].readme_path).to eq('README.md')
      end
    end

    context 'when values are not cached' do
      it 'reads and writes from cache individually' do
        described_class.new(repositories).preload(
          %i[exists? has_visible_content?]
        )

        expect(cache).to receive(:read).exactly(4).times
        expect(cache).to receive(:write).exactly(4).times

        repositories.each(&:exists?)
        repositories.each(&:has_visible_content?)
      end
    end
  end
end