Experimental semi-auto updater for firefox-bin package in nixpkgs

git.rb

$nixpkgs_dir = File.expand_path("~/src/nixpkgs")

def git(*arguments)
  options = if arguments.last.kind_of? Hash
              options = arguments.pop
            else
              {}
            end

  nixpkgs_dir = if options.include?(:nixpkgs_dir)
                  options[:nixpkgs_dir]
                else
                  $nixpkgs_dir
                end

  puts((["git", "-C", nixpkgs_dir] + arguments).join(" "))
  
  output = IO.popen(["git", "-C", nixpkgs_dir] + arguments) do |io|
    io.read
  end

  if not $?.success?
    fail
  end

  output
end

def create_new_branch_at_new_worktree(new_branch_name, worktree_path)
  if git("branch").include?(new_branch_name)
    if File.exist?(worktree_path)
      puts("worktree already exists")

      false
    else
      puts("checking out a branch #{new_branch_name} at #{worktree_path}")
      git("worktree", "add", "-f", worktree_path, new_branch_name)

      true
    end
  else
    puts("fetching upstream...") 
    git("fetch", "upstream")

    puts("creating new branch #{new_branch_name} at #{worktree_path}")
    git("worktree", "add", "-f", "-b", new_branch_name, worktree_path,
        "upstream/master")

    true
  end
end

update.rb

require('open-uri')
require_relative('git')

$user = "taku0"

def read_current_version_in_nixpkgs(sources_relative_path)
  if git("show", "master:" + sources_relative_path) =~ /version = "([0-9.]*)";/
    $1
  else
    nil
  end
end

def get_last_version_at_mozilla(uri)
  available_versions = open(uri) do |io|
    io.read.scan(%r|>([0-9.]*)/</a>|).map do |match|
      match[0].split(".").map(&:to_i)
    end.sort
  end

  if not available_versions.empty?
    available_versions[-1].join(".")
  else
    nil
  end
end

def update_if_needed(package_name, package_relative_path, base_uri)
  sources_relative_path = File.join(package_relative_path, "sources.nix")

  old_version = read_current_version_in_nixpkgs(sources_relative_path)
  new_version = get_last_version_at_mozilla(base_uri)
  
  puts("old version: #{old_version}")
  puts("new version: #{new_version}")
  
  if old_version.nil? || new_version.nil? || old_version == new_version
    return
  end
  
  puts("new version found.")

  new_branch_name = "#{package_name}-#{new_version}"
  worktree_path = File.expand_path("~/tmp/#{new_branch_name}")

  if not create_new_branch_at_new_worktree(new_branch_name, worktree_path)
    puts("delete it to retry")

    return
  end

  Dir.chdir(File.join(worktree_path, package_relative_path))

  puts("getting archives")

  IO.popen(["ruby", "generate_sources.rb", new_version]) do |io|
    IO.write("sources.nix", io.read)
  end

  git("add", File.join(package_relative_path, "sources.nix"),
      :nixpkgs_dir => worktree_path)
  git("commit", "-m", "#{package_name}: #{old_version} -> #{new_version}",
      :nixpkgs_dir => worktree_path)
  git("push", "origin", "HEAD", :nixpkgs_dir => worktree_path)
  system("hub", "compare", "master...#{$user}:#{new_branch_name}")

  puts("building")

  Dir.chdir(worktree_path)
  system("nix-env", "-i", "-f", worktree_path, package_name)
  # system("nix-shell", "-p", "nox", "--run", 'nox-review revs HEAD HEAD^')

  puts("done")
end

puts(Time.now)

update_if_needed(
  "firefox-bin",
  "pkgs/applications/networking/browsers/firefox-bin",
  "http://archive.mozilla.org/pub/firefox/releases/"
)

update_if_needed(
  "thunderbird-bin",
  "pkgs/applications/networking/mailreaders/thunderbird-bin",
  "http://archive.mozilla.org/pub/thunderbird/releases/"
)

puts()