# frozen_string_literal: true require "cases/helper" module ActiveRecord class AttributeDecoratorsTest < ActiveRecord::TestCase class Model < ActiveRecord::Base self.table_name = "attribute_decorators_model" end class StringDecorator < SimpleDelegator def initialize(delegate, decoration = "decorated!") @decoration = decoration super(delegate) end def cast(value) "#{super} #{@decoration}" end alias deserialize cast end setup do @connection = ActiveRecord::Base.connection @connection.create_table :attribute_decorators_model, force: true do |t| t.string :a_string end end teardown do return unless @connection @connection.drop_table "attribute_decorators_model", if_exists: true Model.attribute_type_decorations.clear Model.reset_column_information end test "attributes can be decorated" do model = Model.new(a_string: "Hello") assert_equal "Hello", model.a_string Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } model = Model.new(a_string: "Hello") assert_equal "Hello decorated!", model.a_string end test "decoration does not eagerly load existing columns" do Model.reset_column_information assert_no_queries do Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } end end test "undecorated columns are not touched" do Model.attribute :another_string, :string, default: "something or other" Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } assert_equal "something or other", Model.new.another_string end test "decorators can be chained" do Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } Model.decorate_attribute_type(:a_string, :other) { |t| StringDecorator.new(t) } model = Model.new(a_string: "Hello!") assert_equal "Hello! decorated! decorated!", model.a_string end test "decoration of the same type multiple times is idempotent" do Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } model = Model.new(a_string: "Hello") assert_equal "Hello decorated!", model.a_string end test "decorations occur in order of declaration" do Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } Model.decorate_attribute_type(:a_string, :other) do |type| StringDecorator.new(type, "decorated again!") end model = Model.new(a_string: "Hello!") assert_equal "Hello! decorated! decorated again!", model.a_string end test "decorating attributes does not modify parent classes" do Model.attribute :another_string, :string, default: "whatever" Model.decorate_attribute_type(:a_string, :test) { |t| StringDecorator.new(t) } child_class = Class.new(Model) child_class.decorate_attribute_type(:another_string, :test) { |t| StringDecorator.new(t) } child_class.decorate_attribute_type(:a_string, :other) { |t| StringDecorator.new(t) } model = Model.new(a_string: "Hello!") child = child_class.new(a_string: "Hello!") assert_equal "Hello! decorated!", model.a_string assert_equal "whatever", model.another_string assert_equal "Hello! decorated! decorated!", child.a_string assert_equal "whatever decorated!", child.another_string end class Multiplier < SimpleDelegator def cast(value) return if value.nil? value * 2 end alias deserialize cast end test "decorating with a proc" do Model.attribute :an_int, :integer type_is_integer = proc { |_, type| type.type == :integer } Model.decorate_matching_attribute_types type_is_integer, :multiplier do |type| Multiplier.new(type) end model = Model.new(a_string: "whatever", an_int: 1) assert_equal "whatever", model.a_string assert_equal 2, model.an_int end end end