Module: Mandate::InitializerInjector

Defined in:
lib/mandate/initializer_injector.rb

Class Method Summary collapse

Class Method Details

.extended(base) ⇒ Object



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# File 'lib/mandate/initializer_injector.rb', line 8

def self.extended(base)
  class << base
    def initialize_with(*attrs, **kwattrs, &block)
      kwarg_capture_key = (kwattrs.find(-> { [] }) { |_name, value| value == KWARGS }).first

      define_method :initialize do |*args, **kwargs|
        unless args.length == attrs.length
          raise ArgumentError, "wrong number of arguments (given #{args.length}, expected #{attrs.length})"
        end

        attrs.zip(args).each do |attr, arg|
          instance_variable_set("@#{attr}", arg)
        end

        instance_variable_set("@#{kwarg_capture_key}", {}) if kwarg_capture_key
        kwargs.each do |name, value|
          if kwattrs.key?(name)
            instance_variable_set("@#{name}", value)
          elsif kwarg_capture_key
            instance_variable_get("@#{kwarg_capture_key}")[name] = value
          else
            raise ArgumentError, "unknown keyword: #{name}"
          end
        end

        kwattrs.each do |key, value|
          next unless value == NO_DEFAULT
          next if kwargs.key?(key)

          raise ArgumentError, "Keyword argument was not specified: #{key}"
        end

        instance_eval(&block) if block
      end

      attrs.each do |attr|
        define_method attr do
          instance_variable_get("@#{attr}")
        end
        private attr
      end

      kwattrs.each do |attr, default|
        define_method attr do
          if instance_variable_defined?("@#{attr}")
            instance_variable_get("@#{attr}")
          else
            default
          end
        end
        private attr
      end
    end
  end
end