require 'abstract_unit' require 'active_support/core_ext/array' require 'active_support/core_ext/enumerable' Payment = Struct.new(:price) class SummablePayment < Payment def +(p) self.class.new(price + p.price) end end class EnumerableTests < ActiveSupport::TestCase class GenericEnumerable include Enumerable def initialize(values = [1, 2, 3]) @values = values end def each @values.each{|v| yield v} end end def test_sums enum = GenericEnumerable.new([5, 15, 10]) assert_equal 30, enum.sum assert_equal 60, enum.sum { |i| i * 2} enum = GenericEnumerable.new(%w(a b c)) assert_equal 'abc', enum.sum assert_equal 'aabbcc', enum.sum { |i| i * 2 } payments = GenericEnumerable.new([ Payment.new(5), Payment.new(15), Payment.new(10) ]) assert_equal 30, payments.sum(&:price) assert_equal 60, payments.sum { |p| p.price * 2 } payments = GenericEnumerable.new([ SummablePayment.new(5), SummablePayment.new(15) ]) assert_equal SummablePayment.new(20), payments.sum assert_equal SummablePayment.new(20), payments.sum { |p| p } end def test_nil_sums expected_raise = TypeError assert_raise(expected_raise) { GenericEnumerable.new([5, 15, nil]).sum } payments = GenericEnumerable.new([ Payment.new(5), Payment.new(15), Payment.new(10), Payment.new(nil) ]) assert_raise(expected_raise) { payments.sum(&:price) } assert_equal 60, payments.sum { |p| p.price.to_i * 2 } end def test_empty_sums assert_equal 0, GenericEnumerable.new([]).sum assert_equal 0, GenericEnumerable.new([]).sum { |i| i + 10 } assert_equal Payment.new(0), GenericEnumerable.new([]).sum(Payment.new(0)) end def test_range_sums assert_equal 20, (1..4).sum { |i| i * 2 } assert_equal 10, (1..4).sum assert_equal 10, (1..4.5).sum assert_equal 6, (1...4).sum assert_equal 'abc', ('a'..'c').sum assert_equal 50_000_005_000_000, (0..10_000_000).sum assert_equal 0, (10..0).sum assert_equal 5, (10..0).sum(5) assert_equal 10, (10..10).sum assert_equal 42, (10...10).sum(42) end def test_index_by payments = GenericEnumerable.new([ Payment.new(5), Payment.new(15), Payment.new(10) ]) assert_equal({ 5 => Payment.new(5), 15 => Payment.new(15), 10 => Payment.new(10) }, payments.index_by(&:price)) assert_equal Enumerator, payments.index_by.class if Enumerator.method_defined? :size assert_equal nil, payments.index_by.size assert_equal 42, (1..42).index_by.size end assert_equal({ 5 => Payment.new(5), 15 => Payment.new(15), 10 => Payment.new(10) }, payments.index_by.each(&:price)) end def test_many assert_equal false, GenericEnumerable.new([] ).many? assert_equal false, GenericEnumerable.new([ 1 ] ).many? assert_equal true, GenericEnumerable.new([ 1, 2 ] ).many? assert_equal false, GenericEnumerable.new([] ).many? {|x| x > 1 } assert_equal false, GenericEnumerable.new([ 2 ] ).many? {|x| x > 1 } assert_equal false, GenericEnumerable.new([ 1, 2 ] ).many? {|x| x > 1 } assert_equal true, GenericEnumerable.new([ 1, 2, 2 ]).many? {|x| x > 1 } end def test_many_iterates_only_on_what_is_needed infinity = 1.0/0.0 very_long_enum = 0..infinity assert_equal true, very_long_enum.many? assert_equal true, very_long_enum.many?{|x| x > 100} end def test_exclude? assert_equal true, GenericEnumerable.new([ 1 ]).exclude?(2) assert_equal false, GenericEnumerable.new([ 1 ]).exclude?(1) end def test_without assert_equal [1, 2, 4], GenericEnumerable.new((1..5).to_a).without(3, 5) assert_equal [1, 2, 4], (1..5).to_a.without(3, 5) assert_equal [1, 2, 4], (1..5).to_set.without(3, 5) assert_equal({foo: 1, baz: 3}, {foo: 1, bar: 2, baz: 3}.without(:bar)) end end