require "abstract_unit" require "active_support/core_ext/array" require "active_support/core_ext/enumerable" Payment = Struct.new(:price) ExpandedPayment = Struct.new(:dollars, :cents) 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 assert_typed_equal(e, v, cls, msg = nil) assert_kind_of(cls, v, msg) assert_equal(e, v, msg) 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 } sum = GenericEnumerable.new([3, 5.quo(1)]).sum assert_typed_equal(8, sum, Rational) sum = GenericEnumerable.new([3, 5.quo(1)]).sum(0.0) assert_typed_equal(8.0, sum, Float) sum = GenericEnumerable.new([3, 5.quo(1), 7.0]).sum assert_typed_equal(15.0, sum, Float) sum = GenericEnumerable.new([3, 5.quo(1), Complex(7)]).sum assert_typed_equal(Complex(15), sum, Complex) assert_typed_equal(15, sum.real, Rational) assert_typed_equal(0, sum.imag, Integer) sum = GenericEnumerable.new([3.5, 5]).sum assert_typed_equal(8.5, sum, Float) sum = GenericEnumerable.new([2, 8.5]).sum assert_typed_equal(10.5, sum, Float) sum = GenericEnumerable.new([1.quo(2), 1]).sum assert_typed_equal(3.quo(2), sum, Rational) sum = GenericEnumerable.new([1.quo(2), 1.quo(3)]).sum assert_typed_equal(5.quo(6), sum, Rational) sum = GenericEnumerable.new([2.0, 3.0 * Complex::I]).sum assert_typed_equal(Complex(2.0, 3.0), sum, Complex) assert_typed_equal(2.0, sum.real, Float) assert_typed_equal(3.0, sum.imag, Float) sum = GenericEnumerable.new([1, 2]).sum(10) { |v| v * 2 } assert_typed_equal(16, sum, Integer) 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)) assert_typed_equal 0.0, GenericEnumerable.new([]).sum(0.0), Float 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) assert_typed_equal 20.0, (1..4).sum(0.0) { |i| i * 2 }, Float assert_typed_equal 10.0, (1..4).sum(0.0), Float assert_typed_equal 20.0, (1..4).sum(10.0), Float assert_typed_equal 5.0, (10..0).sum(5.0), Float end def test_array_sums enum = [5, 15, 10] assert_equal 30, enum.sum assert_equal 60, enum.sum { |i| i * 2 } enum = %w(a b c) assert_equal "abc", enum.sum assert_equal "aabbcc", enum.sum { |i| i * 2 } payments = [ 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 = [ SummablePayment.new(5), SummablePayment.new(15) ] assert_equal SummablePayment.new(20), payments.sum assert_equal SummablePayment.new(20), payments.sum { |p| p } sum = [3, 5.quo(1)].sum assert_typed_equal(8, sum, Rational) sum = [3, 5.quo(1)].sum(0.0) assert_typed_equal(8.0, sum, Float) sum = [3, 5.quo(1), 7.0].sum assert_typed_equal(15.0, sum, Float) sum = [3, 5.quo(1), Complex(7)].sum assert_typed_equal(Complex(15), sum, Complex) assert_typed_equal(15, sum.real, Rational) assert_typed_equal(0, sum.imag, Integer) sum = [3.5, 5].sum assert_typed_equal(8.5, sum, Float) sum = [2, 8.5].sum assert_typed_equal(10.5, sum, Float) sum = [1.quo(2), 1].sum assert_typed_equal(3.quo(2), sum, Rational) sum = [1.quo(2), 1.quo(3)].sum assert_typed_equal(5.quo(6), sum, Rational) sum = [2.0, 3.0 * Complex::I].sum assert_typed_equal(Complex(2.0, 3.0), sum, Complex) assert_typed_equal(2.0, sum.real, Float) assert_typed_equal(3.0, sum.imag, Float) sum = [1, 2].sum(10) { |v| v * 2 } assert_typed_equal(16, sum, Integer) 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 assert_nil payments.index_by.size assert_equal 42, (1..42).index_by.size 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 def test_pluck payments = GenericEnumerable.new([ Payment.new(5), Payment.new(15), Payment.new(10) ]) assert_equal [5, 15, 10], payments.pluck(:price) payments = GenericEnumerable.new([ ExpandedPayment.new(5, 99), ExpandedPayment.new(15, 0), ExpandedPayment.new(10, 50) ]) assert_equal [[5, 99], [15, 0], [10, 50]], payments.pluck(:dollars, :cents) end end