# 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