Mixin for Interactor objects. Dependencies: interactor, dry-types

interactor_mixin.rb

require 'interactor'
require 'dry-types'

# Author::    Alejandro Bezdjian
# Copyright:: Copyright (c) 2017 Alejandro Bezdjian
# License::   Apache 2.0

class InteractorMixin
  include Interactor
  
  module Types
    # Check out http://dry-rb.org/gems/dry-types
    include Dry::Types.module
  end

  # Used to access attributes with bare words
  def method_missing(method, *args, &block)
    return context.send(method) if context.respond_to?(method)
    super
  end

  def respond_to_missing?(method_name, include_private = false)
    context.respond_to?(method) || super
  end

  def param(name, options = {})
    set_default!(name, options[:default])
    check_type!(name, options[:type])
    check_presence!(name, options[:required])
  end

  def set_default!(name, value)
    context[name] = value if attribute(name).nil? && present?(value)
  end

  def check_type!(name, type)
    fail!("Expected #{name} to be #{type.name}") if present?(type) && invalid_type?(type, name)
  end

  def check_presence!(name, required)
    fail!("Expected #{name} to be present") if attribute(name).nil? && required
  end

  def present?(object)
    return false if object.nil?
    true
  end

  # Method to get value from Interactor's context
  def attribute(name)
    context.send(name)
  end

  # Params:
  # * +type+ - A class or a Dry::Type is expected
  def valid_type?(type, attribute_name)
    return type.valid?(attribute(attribute_name)) if type.respond_to?(:valid?)
    attribute(attribute_name).is_a?(type)
  end

  # Params:
  # * +type+ - A Dry::Type is expected
  def invalid_type?(type, attribute_name)
    !valid_type?(type, attribute_name)
  end

  # Method to stop Interactor's execution in one step
  def fail!(message)
    context.error = message
    context.fail!
  end

  # Method used to add the final result to the Interactor object
  def result(something)
    context.result = something
  end
end

test_interactor.rb

class TestInteractor < InteractorMixin
  before do
    param :param1, type: Types::String, required: true
    param :param2, type: Types::Coercible::Float
    param :param3, type: Pepe
  end

  def call
    puts param1
    puts param2
    puts param3
  end
end