##
# Enumerable(Ext) Test

assert("Enumerable#drop") do
  a = [1, 2, 3, 4, 5, 0]

  assert_equal [4, 5, 0], a.drop(3)
  assert_equal [], a.drop(6)
end

assert("Enumerable#drop_while") do
  a = [1, 2, 3, 4, 5, 0]
  assert_equal [3, 4, 5, 0], a.drop_while {|i| i < 3 }
end

assert("Enumerable#take") do
  a = [1, 2, 3, 4, 5, 0]
  assert_equal [1, 2, 3], a.take(3)
end

assert("Enumerable#take_while") do
  a = [1, 2, 3, 4, 5, 0]
  assert_equal [1, 2], a.take_while {|i| i < 3}
end

assert("Enumerable#each_cons") do
  a = []
  (1..5).each_cons(3){|e| a << e}
  assert_equal [[1, 2, 3], [2, 3, 4], [3, 4, 5]], a
end

assert("Enumerable#each_slice") do
  a = []
  (1..10).each_slice(3){|e| a << e}
  assert_equal [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]], a
end

assert("Enumerable#group_by") do
  r = (1..6).group_by {|i| i % 3 }
  assert_equal [3, 6], r[0]
  assert_equal [1, 4], r[1]
  assert_equal [2, 5], r[2]
end

assert("Enumerable#sort_by") do
  assert_equal ["car", "train", "bicycle"], %w{car bicycle train}.sort_by {|e| e.length}
end

assert("Enumerable#first") do
  a = Object.new
  a.extend Enumerable
  def a.each
    yield 1
    yield 2
    yield 3
  end
  assert_equal 1, a.first
  assert_equal [1, 2], a.first(2)
  assert_equal [1, 2, 3], a.first(10)
  a = Object.new
  a.extend Enumerable
  def a.each
  end
  assert_nil a.first
end

assert("Enumerable#count") do
  a = [1, 2, 4, 2]
  assert_equal 4, a.count
  assert_equal 2, a.count(2)
  assert_equal 3, a.count{|x| x % 2 == 0}
end

assert("Enumerable#flat_map") do
  assert_equal [1, 2, 3, 4], [1, 2, 3, 4].flat_map { |e| e }
  assert_equal [1, -1, 2, -2, 3, -3, 4, -4], [1, 2, 3, 4].flat_map { |e| [e, -e] }
  assert_equal [1, 2, 100, 3, 4, 100], [[1, 2], [3, 4]].flat_map { |e| e + [100] }
end

assert("Enumerable#max_by") do
  assert_equal "albatross", %w[albatross dog horse].max_by { |x| x.length }
end

assert("Enumerable#min_by") do
  assert_equal "dog", %w[albatross dog horse].min_by { |x| x.length }
end

assert("Enumerable#minmax") do
  a = %w(albatross dog horse)
  assert_equal ["albatross", "horse"], a.minmax
  assert_equal ["dog", "albatross"], a.minmax { |a, b| a.length <=> b.length }
end