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require File.dirname(__FILE__) + '/../abstract_unit'
Payment = Struct.new(:price)
class SummablePayment < Payment
def +(p) self.class.new(price + p.price) end
end
class EnumerableTests < Test::Unit::TestCase
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
objects.group_by {|object| object.name}.each do |name, group|
assert group.all? {|person| person.name == name}
end
end
def test_sums
assert_equal 30, [5, 15, 10].sum
assert_equal 30, [5, 15, 10].sum { |i| i }
assert_equal 'abc', %w(a b c).sum
assert_equal 'abc', %w(a b c).sum { |i| i }
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 }
end
def test_nil_sums
expected_raise = TypeError
assert_raise(expected_raise) { [5, 15, nil].sum }
payments = [ 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, [].sum
assert_equal 0, [].sum { |i| i }
assert_equal Payment.new(0), [].sum(Payment.new(0))
end
def test_index_by
payments = [ Payment.new(5), Payment.new(15), Payment.new(10) ]
assert_equal({ 5 => payments[0], 15 => payments[1], 10 => payments[2] },
payments.index_by { |p| p.price })
end
end
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