zip_file_generator.rb

require "zip/zip"

# Usage:
#   directory_to_zip = "/tmp/input"
#   output_file = "/tmp/out.zip"
#   zf = ZipFileGenerator.new(directoryToZip, output_file).write
class ZipFileGenerator
  EXCLUDED_ENTRIES = [".", "..", ".git"]

  def initialize(input_dir, output_file)
    @input_dir = input_dir
    @output_file = output_file
  end

  def write
    io = Zip::ZipFile.open(@output_file, Zip::ZipFile::CREATE)
    write_entries(strip_entries(@input_dir), "", io)
    io.close
  end

  private

  def write_entries(entries, path, io)
    entries.each do |e|
      byebug
      zip_file_path = path.blank? ? e : File.join(path, e)
      disk_file_path = File.join(@input_dir, zip_file_path)
      if File.directory?(disk_file_path)
        io.mkdir(zip_file_path)
        subdir = strip_entries(disk_file_path)
        write_entries(subdir, zip_file_path, io)
      else
        io.get_output_stream(zip_file_path) do |f|
          f.puts(File.open(disk_file_path, "rb").read)
        end
      end
    end
  end

  def strip_entries(dir)
    Dir.entries(dir).delete_if { |a| EXCLUDED_ENTRIES.include?(a) }
  end
end