Simple File Downloader in Ruby using Net::HTTP, it downloads by chuncks into a file to keep memory as low as possible

file_downloader.rb

# frozen_string_literal: true

require "net/http"

class FileDownloader
  attr_reader :uri, :http_response

  HTTPS_SCHEME = "https"

  def initialize(url:, target:)
    @uri = URI(url)
    @target = target
    @http_response = nil
  end

  def self.download(url:, target:)
    new(url: url, target: target).download
  end

  def download
    Net::HTTP.start(@uri.host, @uri.port, use_ssl: https?) do |http|
      request = Net::HTTP::Get.new @uri
      http.request request do |response|
        @http_response = response
        case response.code
        when "302"
          @uri = URI(response["location"])
          return download
        when "200"
          @target.binmode # no newline conversion | no encoding conversion | encoding is ASCII-8BIT
          response.read_body do |chunk|
            chunk = yield chunk if block_given?
            @target.write(chunk)
          end
          return @target.tap(&:close)
        else
          raise Net::HTTPError.new(response.body, nil)
        end
      end
    end
  end

  private

  def https?
    @uri.scheme == HTTPS_SCHEME
  end
end

# USAGE
file = FileDownloader.download(url: "url-to-file", target: Tempfile.new)

file = Tempfile.new
FileDownloader.download(url: "url-to-file", target: file)