require "abstract_unit" require "active_support/core_ext/module" Somewhere = Struct.new(:street, :city) do attr_accessor :name end Someone = Struct.new(:name, :place) do delegate :street, :city, :to_f, to: :place delegate :name=, to: :place, prefix: true delegate :upcase, to: "place.city" delegate :table_name, to: :class delegate :table_name, to: :class, prefix: true def self.table_name "some_table" end self::FAILED_DELEGATE_LINE = __LINE__ + 1 delegate :foo, to: :place self::FAILED_DELEGATE_LINE_2 = __LINE__ + 1 delegate :bar, to: :place, allow_nil: true private def private_name "Private" end end Invoice = Struct.new(:client) do delegate :street, :city, :name, to: :client, prefix: true delegate :street, :city, :name, to: :client, prefix: :customer end Project = Struct.new(:description, :person) do delegate :name, to: :person, allow_nil: true delegate :to_f, to: :description, allow_nil: true end Developer = Struct.new(:client) do delegate :name, to: :client, prefix: nil end Event = Struct.new(:case) do delegate :foo, to: :case end Tester = Struct.new(:client) do delegate :name, to: :client, prefix: false def foo; 1; end end Product = Struct.new(:name) do delegate :name, to: :manufacturer, prefix: true delegate :name, to: :type, prefix: true def manufacturer @manufacturer ||= begin nil.unknown_method end end def type @type ||= begin nil.type_name end end end DecoratedTester = Struct.new(:client) do delegate_missing_to :client end class DecoratedReserved delegate_missing_to :case attr_reader :case def initialize(kase) @case = kase end end class Block def hello? true end end HasBlock = Struct.new(:block) do delegate :hello?, to: :block end class ParameterSet delegate :[], :[]=, to: :@params def initialize @params = { foo: "bar" } end end class Name delegate :upcase, to: :@full_name def initialize(first, last) @full_name = "#{first} #{last}" end end class SideEffect attr_reader :ints delegate :to_i, to: :shift, allow_nil: true delegate :to_s, to: :shift def initialize @ints = [1, 2, 3] end def shift @ints.shift end end class ModuleTest < ActiveSupport::TestCase def setup @david = Someone.new("David", Somewhere.new("Paulina", "Chicago")) end def test_delegation_to_methods assert_equal "Paulina", @david.street assert_equal "Chicago", @david.city end def test_delegation_to_assignment_method @david.place_name = "Fred" assert_equal "Fred", @david.place.name end def test_delegation_to_index_get_method @params = ParameterSet.new assert_equal "bar", @params[:foo] end def test_delegation_to_index_set_method @params = ParameterSet.new @params[:foo] = "baz" assert_equal "baz", @params[:foo] end def test_delegation_down_hierarchy assert_equal "CHICAGO", @david.upcase end def test_delegation_to_instance_variable david = Name.new("David", "Hansson") assert_equal "DAVID HANSSON", david.upcase end def test_delegation_to_class_method assert_equal "some_table", @david.table_name assert_equal "some_table", @david.class_table_name end def test_missing_delegation_target assert_raise(ArgumentError) do Name.send :delegate, :nowhere end assert_raise(ArgumentError) do Name.send :delegate, :noplace, tos: :hollywood end end def test_delegation_target_when_prefix_is_true assert_nothing_raised do Name.send :delegate, :go, to: :you, prefix: true end assert_nothing_raised do Name.send :delegate, :go, to: :_you, prefix: true end assert_raise(ArgumentError) do Name.send :delegate, :go, to: :You, prefix: true end assert_raise(ArgumentError) do Name.send :delegate, :go, to: :@you, prefix: true end end def test_delegation_prefix invoice = Invoice.new(@david) assert_equal "David", invoice.client_name assert_equal "Paulina", invoice.client_street assert_equal "Chicago", invoice.client_city end def test_delegation_custom_prefix invoice = Invoice.new(@david) assert_equal "David", invoice.customer_name assert_equal "Paulina", invoice.customer_street assert_equal "Chicago", invoice.customer_city end def test_delegation_prefix_with_nil_or_false assert_equal "David", Developer.new(@david).name assert_equal "David", Tester.new(@david).name end def test_delegation_prefix_with_instance_variable assert_raise ArgumentError do Class.new do def initialize(client) @client = client end delegate :name, :address, to: :@client, prefix: true end end end def test_delegation_with_allow_nil rails = Project.new("Rails", Someone.new("David")) assert_equal "David", rails.name end def test_delegation_with_allow_nil_and_nil_value rails = Project.new("Rails") assert_nil rails.name end # Ensures with check for nil, not for a falseish target. def test_delegation_with_allow_nil_and_false_value project = Project.new(false, false) assert_raise(NoMethodError) { project.name } end def test_delegation_with_allow_nil_and_invalid_value rails = Project.new("Rails", "David") assert_raise(NoMethodError) { rails.name } end def test_delegation_with_allow_nil_and_nil_value_and_prefix Project.class_eval do delegate :name, to: :person, allow_nil: true, prefix: true end rails = Project.new("Rails") assert_nil rails.person_name end def test_delegation_without_allow_nil_and_nil_value david = Someone.new("David") assert_raise(Module::DelegationError) { david.street } end def test_delegation_to_method_that_exists_on_nil nil_person = Someone.new(nil) assert_equal 0.0, nil_person.to_f end def test_delegation_to_method_that_exists_on_nil_when_allowing_nil nil_project = Project.new(nil) assert_equal 0.0, nil_project.to_f end def test_delegation_does_not_raise_error_when_removing_singleton_instance_methods parent = Class.new do def self.parent_method; end end assert_nothing_raised do Class.new(parent) do class << self delegate :parent_method, to: :superclass end end end end def test_delegation_line_number _, line = Someone.instance_method(:foo).source_location assert_equal Someone::FAILED_DELEGATE_LINE, line end def test_delegate_line_with_nil _, line = Someone.instance_method(:bar).source_location assert_equal Someone::FAILED_DELEGATE_LINE_2, line end def test_delegation_exception_backtrace someone = Someone.new("foo", "bar") someone.foo rescue NoMethodError => e file_and_line = "#{__FILE__}:#{Someone::FAILED_DELEGATE_LINE}" # We can't simply check the first line of the backtrace, because JRuby reports the call to __send__ in the backtrace. assert e.backtrace.any? { |a| a.include?(file_and_line) }, "[#{e.backtrace.inspect}] did not include [#{file_and_line}]" end def test_delegation_exception_backtrace_with_allow_nil someone = Someone.new("foo", "bar") someone.bar rescue NoMethodError => e file_and_line = "#{__FILE__}:#{Someone::FAILED_DELEGATE_LINE_2}" # We can't simply check the first line of the backtrace, because JRuby reports the call to __send__ in the backtrace. assert e.backtrace.any? { |a| a.include?(file_and_line) }, "[#{e.backtrace.inspect}] did not include [#{file_and_line}]" end def test_delegation_invokes_the_target_exactly_once se = SideEffect.new assert_equal 1, se.to_i assert_equal [2, 3], se.ints assert_equal "2", se.to_s assert_equal [3], se.ints end def test_delegation_doesnt_mask_nested_no_method_error_on_nil_receiver product = Product.new("Widget") # Nested NoMethodError is a different name from the delegation assert_raise(NoMethodError) { product.manufacturer_name } # Nested NoMethodError is the same name as the delegation assert_raise(NoMethodError) { product.type_name } end def test_delegation_with_method_arguments has_block = HasBlock.new(Block.new) assert has_block.hello? end def test_delegate_to_missing_with_method assert_equal "David", DecoratedTester.new(@david).name end def test_delegate_to_missing_with_reserved_methods assert_equal "David", DecoratedReserved.new(@david).name end def test_delegate_to_missing_does_not_delegate_to_private_methods e = assert_raises(NoMethodError) do DecoratedReserved.new(@david).private_name end assert_match(/undefined method `private_name' for/, e.message) end def test_delegate_to_missing_does_not_delegate_to_fake_methods e = assert_raises(NoMethodError) do DecoratedReserved.new(@david).my_fake_method end assert_match(/undefined method `my_fake_method' for/, e.message) end def test_delegate_with_case event = Event.new(Tester.new) assert_equal 1, event.foo end end