Copy versions from Gemfile.lock to Gemfile (with iternal tests!)

copy_versions_to_new_gemfile.rb

# frozen_string_literal: true
require 'pry'

module Bundler
  class GemVersionsFiller
    GEM_NAME_REGEXP  = /\* ([\w_-]+) /
    IGNORE = %w(xxx)

    attr_reader :old_gemfile_lines, :new_gemfile_lines

    def initialize(gem_file, gemlock_file)
      if gem_file.is_a?(String)
        @old_gemfile_lines = lines_from(gem_file)
        @gemlock_file_lines = lines_from(gemlock_file)
      elsif gem_file.is_a?(File)
        @old_gemfile_lines = gem_file.readlines
        @gemlock_file_lines = gemlock_file.readlines
      else
        raise "Unsupported input. Use String or File"
      end
      @new_gemfile_lines = []
    end

    def append_versions
      old_gemfile_lines.each do |line|
        if change_line?(line)
          # puts("changing line: #{line}")
          new_gemfile_lines << append_version_to(line)
        else
          new_gemfile_lines << line
        end
      end
      return make_result
    end

    private

    def lines_from(multiline_string)
      lines = []
      multiline_string.each_line { |line| lines << line }
      lines
    end

    def change_line?(line)
      return false if line.empty? || line.match(/git:|github:|^#/)
      return false if line.match(/,\s?'[\d.]+'/) # gemline with version
      !line.match(/^\s*gem/).nil?
    end

    def append_version_to(line)
      m = line.match(/^\s*gem\s+['"](\w[-\w]+(.rb)?)['"]/)
      raise "Gem name could not be found on line #{line}" if m.nil?
      gemname = m[1]

      line.gsub(m[0], m[0] + ", '#{version_from_gemlock(gemname)}'")
    end

    def unlocked_gems
      File.readlines('Gemfile').reject { |line| line =~ /git:|github:|^#/ || IGNORE.detect { |i| line.include?(i) } }
    end

    def version_from_gemlock(gemname)
      v = locked_versions[gemname]
      raise "#{gemname} not founded between locked versions! Locked versions: #{locked_versions}" if v.nil?
      v
    end

    def locked_versions
      @locked_versions ||= read_locked_versions
    end

    def read_locked_versions
      versions = {}
      read_versions = false
      intendation = nil

      @gemlock_file_lines.each do |line|
        read_versions = true if line.match(/^GEM/)
        break if line.match(/^PLATFORMS/)
        next unless read_versions
        if (m = line.match(/(\s*)(\w[-\w]*(.rb)?) \((.*)\)$/)) # gem with version
          intendation = m[1] if intendation.nil?
          versions[m[2]] = m[4] if m[1] == intendation #just the main ones
        end
      end
      puts("LOCKED_VERSIONS: #{versions}")
      versions
    end

    def make_result
      new_gemfile_lines.join('')
    end
  end
end

def test_it
  gemfile = <<-GEMFILE
# frozen_string_literal: true
source 'https://rubygems.org'
ruby '2.4.1'
gem 'cocoon', '1.2.9'
gem 'hash-diff' # I need this badly
gem 'ruby-eet-cz', github: 'ciihla/ruby-eet-cz', require: 'eet_cz'
gem 'activemodel-serializers-xml', git: 'https://github.com/rails/activemodel-serializers-xml', require: false
gem 'gtin.rb'
group :development, :test do
  gem 'factory_girl_rails'
  gem 'faker', '1.7.2'
  gem "letter_opener"
end
GEMFILE

  gemfilelock = <<-GEMFILELOCK
GIT
  remote: git://github.com/ciihla/ruby-eet-cz.git
  revision: 8fc7897e484de52c7058847e7a2741fe66bfde61
  specs:
    ruby-eet-cz (1.0.0.pre)
      activemodel (>= 4.2)
      activesupport (>= 4.2)
      savon (~> 2.11.0)

GIT
  remote: https://github.com/rails/activemodel-serializers-xml
  revision: dd9c0acf26aab111ebc647cd8deb99ebc6946531
  specs:
    activemodel-serializers-xml (1.0.1)
      activemodel (> 5.x)
      activesupport (> 5.x)
      builder (~> 3.1)

GEM
remote: https://rubygems.org/
  specs:
    actionmailer (5.1.2)
      actionpack (= 5.1.2)
      actionview (= 5.1.2)
    active_model_serializers (0.10.6)
      actionpack (>= 4.1, < 6)
      activemodel (>= 4.1, < 6)
      case_transform (>= 0.2)
      jsonapi-renderer (>= 0.1.1.beta1, < 0.2)
    cocoon (1.2.10)
    database_cleaner (1.6.1)
    factory_girl (4.8.0)
      activesupport (>= 3.0.0)
    factory_girl_rails (4.8.0)
      factory_girl (~> 4.8.0)
      railties (>= 3.0.0)
    faker (1.7.3)
      i18n (~> 0.5)
    gtin.rb (0.1.2)
    hash-diff (0.3.4)
    letter_opener (1.4.1)
      launchy (~> 2.2)
    public_suffix (2.0.5)
    puma (3.9.1)
    pundit (1.1.0)
      activesupport (>= 3.0.0)
    rake (12.0.0)
    xpath (2.1.0)
      nokogiri (~> 1.3)

PLATFORMS
  ruby

DEPENDENCIES
  database_cleaner
  puma

RUBY VERSION
   ruby 2.4.1p111

BUNDLED WITH
   1.15.1

GEMFILELOCK

  result = Bundler::GemVersionsFiller.new(gemfile, gemfilelock).append_versions

  expected_result = <<-EXPECTEDGEMFILE
# frozen_string_literal: true
source 'https://rubygems.org'
ruby '2.4.1'
gem 'cocoon', '1.2.9'
gem 'hash-diff', '0.3.4' # I need this badly
gem 'ruby-eet-cz', github: 'ciihla/ruby-eet-cz', require: 'eet_cz'
gem 'activemodel-serializers-xml', git: 'https://github.com/rails/activemodel-serializers-xml', require: false
gem 'gtin.rb', '0.1.2'
group :development, :test do
  gem 'factory_girl_rails', '4.8.0'
  gem 'faker', '1.7.2'
  gem "letter_opener", '1.4.1'
end
EXPECTEDGEMFILE

  if result.eql? expected_result
    puts 'self test OK'
  else
    puts "self test FAILED: expected ------\n#{expected_result}-------- \n\ngot -----\n#{result}--------"
  end
end

test_it

gemfile = File.open('Gemfile', 'r')
gemfile_lock = File.open('Gemfile.lock', 'r')
new_gemfile_content = Bundler::GemVersionsFiller.new(gemfile, gemfile_lock).append_versions
gemfile.close
gemfile_lock.close

gemfile = File.open('Gemfile_with_versions', 'w')
gemfile.write(new_gemfile_content)
gemfile.close