Asynchronous files downloader.

dl.rb

# frozen_string_literal: true

require 'down'
require 'dry/monads'
require 'dry/monads/result'

Down.backend :http

module DL
  class Run
    include Dry::Monads[:task]

    attr_reader :urls
    attr_reader :destination

    def initialize(urls:, destination:)
      @urls = urls
      @destination = destination
    end

    def call
      @urls.map do |url|
        Task[:io] { Down.download(url, destination: destination) }
      end.map(&:to_result)
    end
  end
end

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

gem 'down'
gem 'dry-monads'
gem 'http'