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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 < Test::Unit::TestCase
Enumerator = [].each.class
class GenericEnumerable
include Enumerable
def initialize(values = [1, 2, 3])
@values = values
end
def each
@values.each{|v| yield v}
end
end
def test_group_by
names = %w(marcel sam david jeremy)
klass = Struct.new(:name)
objects = (1..50).inject([]) do |people,|
p = klass.new
p.name = names.sort_by { rand }.first
people << p
end
enum = GenericEnumerable.new(objects)
grouped = enum.group_by { |object| object.name }
grouped.each do |name, group|
assert group.all? { |person| person.name == name }
end
assert_equal objects.uniq.map(&:name), grouped.keys
assert({}.merge(grouped), "Could not convert ActiveSupport::OrderedHash into Hash")
assert_equal Enumerator, enum.group_by.class
assert_equal grouped, enum.group_by.each(&:name)
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
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 { |p| p.price })
assert_equal Enumerator, payments.index_by.class
assert_equal({ 5 => Payment.new(5), 15 => Payment.new(15), 10 => Payment.new(10) },
payments.index_by.each { |p| p.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
end
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