brew/Library/Homebrew/cask/lib/hbc/source/path_base.rb

require "rubygems"

class Hbc::Source::PathBase
  # derived classes must define method self.me?

  def self.path_for_query(query)
    query_string = query.to_s
    Pathname.new(query_string.end_with?(".rb") ? query_string : query_string + ".rb")
  end

  attr_reader :path

  def initialize(path)
    @path = Pathname(path).expand_path
  end

  def load
    raise Hbc::CaskError, "File '#{path}' does not exist"      unless path.exist?
    raise Hbc::CaskError, "File '#{path}' is not readable"     unless path.readable?
    raise Hbc::CaskError, "File '#{path}' is not a plain file" unless path.file?
    load_cask
  end

  def to_s
    # stringify to fully-resolved location
    path.to_s
  end

  private

  def load_cask
    instance_eval(cask_contents, __FILE__, __LINE__)
  rescue Hbc::CaskError, StandardError, ScriptError => e
    # bug: e.message.concat doesn't work with Hbc::CaskError exceptions
    raise e, e.message.concat(" while loading '#{path}'")
  end

  def cask_contents
    File.open(path, "rb") do |handle|
      contents = handle.read
      if defined?(Encoding)
        contents.force_encoding("UTF-8")
      else
        contents
      end
    end
  end

  def cask(header_token, &block)
    build_cask(Hbc::Cask, header_token, &block)
  end

  def test_cask(header_token, &block)
    build_cask(Hbc::TestCask, header_token, &block)
  end

  def build_cask(cask_class, header_token, &block)
    if header_token.is_a?(Hash)
      # Cask file is using old `cask :v1 => 'token'` syntax
      header_token = header_token.values.first
    end
    raise Hbc::CaskTokenDoesNotMatchError.new(cask_token, header_token) unless cask_token == header_token
    cask_class.new(cask_token, sourcefile_path: path, &block)
  end

  def cask_token
    path.basename.to_s.sub(%r{\.rb}, "")
  end
end