# frozen_string_literal: false
require 'test/unit'
require 'delegate'
require 'timeout'
require 'bigdecimal'
require 'rbconfig/sizeof'

class TestRange < Test::Unit::TestCase
  def test_new
    assert_equal((0..2), Range.new(0, 2))
    assert_equal((0..2), Range.new(0, 2, false))
    assert_equal((0...2), Range.new(0, 2, true))

    assert_raise(ArgumentError) { (1.."3") }

    assert_equal((0..nil), Range.new(0, nil, false))
    assert_equal((0...nil), Range.new(0, nil, true))

    obj = Object.new
    def obj.<=>(other)
      raise RuntimeError, "cmp"
    end
    assert_raise_with_message(RuntimeError, "cmp") { (obj..3) }
  end

  def test_frozen_initialize
    r = Range.allocate
    r.freeze
    assert_raise(FrozenError){r.__send__(:initialize, 1, 2)}
  end

  def test_range_string
    # XXX: Is this really the test of Range?
    assert_equal([], ("a" ... "a").to_a)
    assert_equal(["a"], ("a" .. "a").to_a)
    assert_equal(["a"], ("a" ... "b").to_a)
    assert_equal(["a", "b"], ("a" .. "b").to_a)
    assert_equal([*"a".."z", "aa"], ("a"..).take(27))
  end

  def test_range_numeric_string
    assert_equal(["6", "7", "8"], ("6".."8").to_a, "[ruby-talk:343187]")
    assert_equal(["6", "7"], ("6"..."8").to_a)
    assert_equal(["9", "10"], ("9".."10").to_a)
    assert_equal(["9", "10"], ("9"..).take(2))
    assert_equal(["09", "10"], ("09".."10").to_a, "[ruby-dev:39361]")
    assert_equal(["9", "10"], (SimpleDelegator.new("9").."10").to_a)
    assert_equal(["9", "10"], (SimpleDelegator.new("9")..).take(2))
    assert_equal(["9", "10"], ("9"..SimpleDelegator.new("10")).to_a)
  end

  def test_range_symbol
    assert_equal([:a, :b], (:a .. :b).to_a)
  end

  def test_evaluation_order
    arr = [1,2]
    r = (arr.shift)..(arr.shift)
    assert_equal(1..2, r, "[ruby-dev:26383]")
  end

  class DuckRange
    def initialize(b,e,excl=false)
      @begin = b
      @end = e
      @excl = excl
    end
    attr_reader :begin, :end

    def exclude_end?
      @excl
    end
  end

  def test_duckrange
    assert_equal("bc", "abcd"[DuckRange.new(1,2)])
  end

  def test_min
    assert_equal(1, (1..2).min)
    assert_equal(nil, (2..1).min)
    assert_equal(1, (1...2).min)
    assert_equal(1, (1..).min)

    assert_equal(1.0, (1.0..2.0).min)
    assert_equal(nil, (2.0..1.0).min)
    assert_equal(1, (1.0...2.0).min)
    assert_equal(1, (1.0..).min)

    assert_equal(0, (0..0).min)
    assert_equal(nil, (0...0).min)

    assert_equal([0,1,2], (0..10).min(3))
    assert_equal([0,1], (0..1).min(3))
    assert_equal([0,1,2], (0..).min(3))

    assert_raise(RangeError) { (0..).min {|a, b| a <=> b } }
  end

  def test_max
    assert_equal(2, (1..2).max)
    assert_equal(nil, (2..1).max)
    assert_equal(1, (1...2).max)
    assert_raise(RangeError) { (1..).max }
    assert_raise(RangeError) { (1...).max }

    assert_equal(2.0, (1.0..2.0).max)
    assert_equal(nil, (2.0..1.0).max)
    assert_raise(TypeError) { (1.0...2.0).max }
    assert_raise(TypeError) { (1...1.5).max }
    assert_raise(TypeError) { (1.5...2).max }

    assert_equal(-0x80000002, ((-0x80000002)...(-0x80000001)).max)

    assert_equal(0, (0..0).max)
    assert_equal(nil, (0...0).max)

    assert_equal([10,9,8], (0..10).max(3))
    assert_equal([9,8,7], (0...10).max(3))
    assert_raise(RangeError) { (1..).max(3) }
    assert_raise(RangeError) { (1...).max(3) }
  end

  def test_initialize_twice
    r = eval("1..2")
    assert_raise(NameError) { r.instance_eval { initialize 3, 4 } }
    assert_raise(NameError) { r.instance_eval { initialize_copy 3..4 } }
  end

  def test_uninitialized_range
    r = Range.allocate
    s = Marshal.dump(r)
    r = Marshal.load(s)
    assert_nothing_raised { r.instance_eval { initialize 5, 6} }
  end

  def test_marshal
    r = 1..2
    assert_equal(r, Marshal.load(Marshal.dump(r)))
    r = 1...2
    assert_equal(r, Marshal.load(Marshal.dump(r)))
    r = (1..)
    assert_equal(r, Marshal.load(Marshal.dump(r)))
    r = (1...)
    assert_equal(r, Marshal.load(Marshal.dump(r)))
  end

  def test_bad_value
    assert_raise(ArgumentError) { (1 .. :a) }
  end

  def test_exclude_end
    assert_not_predicate(0..1, :exclude_end?)
    assert_predicate(0...1, :exclude_end?)
    assert_not_predicate(0.., :exclude_end?)
    assert_predicate(0..., :exclude_end?)
  end

  def test_eq
    r = (0..1)
    assert_equal(r, r)
    assert_equal(r, (0..1))
    assert_not_equal(r, 0)
    assert_not_equal(r, (1..2))
    assert_not_equal(r, (0..2))
    assert_not_equal(r, (0...1))
    assert_not_equal(r, (0..nil))
    subclass = Class.new(Range)
    assert_equal(r, subclass.new(0,1))

    r = (0..nil)
    assert_equal(r, r)
    assert_equal(r, (0..nil))
    assert_not_equal(r, 0)
    assert_not_equal(r, (0...nil))
    subclass = Class.new(Range)
    assert_equal(r, subclass.new(0,nil))
  end

  def test_eql
    r = (0..1)
    assert_operator(r, :eql?, r)
    assert_operator(r, :eql?, 0..1)
    assert_not_operator(r, :eql?, 0)
    assert_not_operator(r, :eql?, 1..2)
    assert_not_operator(r, :eql?, 0..2)
    assert_not_operator(r, :eql?, 0...1)
    subclass = Class.new(Range)
    assert_operator(r, :eql?, subclass.new(0,1))

    r = (0..nil)
    assert_operator(r, :eql?, r)
    assert_operator(r, :eql?, 0..nil)
    assert_not_operator(r, :eql?, 0)
    assert_not_operator(r, :eql?, 0...nil)
    subclass = Class.new(Range)
    assert_operator(r, :eql?, subclass.new(0,nil))
  end

  def test_hash
    assert_kind_of(Integer, (0..1).hash)
    assert_equal((0..1).hash, (0..1).hash)
    assert_not_equal((0..1).hash, (0...1).hash)
    assert_equal((0..nil).hash, (0..nil).hash)
    assert_not_equal((0..nil).hash, (0...nil).hash)
  end

  def test_step
    a = []
    (0..10).step {|x| a << x }
    assert_equal([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], a)

    a = []
    (0..).step {|x| a << x; break if a.size == 10 }
    assert_equal([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], a)

    a = []
    (0..10).step(2) {|x| a << x }
    assert_equal([0, 2, 4, 6, 8, 10], a)

    a = []
    (0..).step(2) {|x| a << x; break if a.size == 10 }
    assert_equal([0, 2, 4, 6, 8, 10, 12, 14, 16, 18], a)

    assert_kind_of(Enumerator::ArithmeticSequence, (0..10).step)
    assert_kind_of(Enumerator::ArithmeticSequence, (0..10).step(2))
    assert_kind_of(Enumerator::ArithmeticSequence, (0..10).step(0.5))
    assert_kind_of(Enumerator::ArithmeticSequence, (10..0).step(-1))

    assert_raise(ArgumentError) { (0..10).step(0) { } }
    assert_raise(ArgumentError) { (0..).step(-1) { } }
    assert_raise(ArgumentError) { (0..).step(0) { } }

    a = []
    ("a" .. "z").step(2) {|x| a << x }
    assert_equal(%w(a c e g i k m o q s u w y), a)

    a = []
    ("a" .. ).step(2) {|x| a << x; break if a.size == 13 }
    assert_equal(%w(a c e g i k m o q s u w y), a)

    a = []
    ("a" .. "z").step(2**32) {|x| a << x }
    assert_equal(["a"], a)

    a = []
    (:a .. :z).step(2) {|x| a << x }
    assert_equal(%i(a c e g i k m o q s u w y), a)

    a = []
    (:a .. ).step(2) {|x| a << x; break if a.size == 13 }
    assert_equal(%i(a c e g i k m o q s u w y), a)

    a = []
    (:a .. :z).step(2**32) {|x| a << x }
    assert_equal([:a], a)

    a = []
    (2**32-1 .. 2**32+1).step(2) {|x| a << x }
    assert_equal([4294967295, 4294967297], a)
    zero = (2**32).coerce(0).first
    assert_raise(ArgumentError) { (2**32-1 .. 2**32+1).step(zero) { } }
    a = []
    (2**32-1 .. ).step(2) {|x| a << x; break if a.size == 2 }
    assert_equal([4294967295, 4294967297], a)

    max = RbConfig::LIMITS["FIXNUM_MAX"]
    a = []
    (max..).step {|x| a << x; break if a.size == 2 }
    assert_equal([max, max+1], a)
    a = []
    (max..).step(max) {|x| a << x; break if a.size == 4 }
    assert_equal([max, 2*max, 3*max, 4*max], a)

    o1 = Object.new
    o2 = Object.new
    def o1.<=>(x); -1; end
    def o2.<=>(x); 0; end
    assert_raise(TypeError) { (o1..o2).step(1) { } }
    assert_raise(TypeError) { (o1..).step(1) { } }

    class << o1; self; end.class_eval do
      define_method(:succ) { o2 }
    end
    a = []
    (o1..o2).step(1) {|x| a << x }
    assert_equal([o1, o2], a)

    a = []
    (o1...o2).step(1) {|x| a << x }
    assert_equal([o1], a)

    assert_nothing_raised("[ruby-dev:34557]") { (0..2).step(0.5) {|x| } }

    a = []
    (0..2).step(0.5) {|x| a << x }
    assert_equal([0, 0.5, 1.0, 1.5, 2.0], a)

    a = []
    (0..).step(0.5) {|x| a << x; break if a.size == 5 }
    assert_equal([0, 0.5, 1.0, 1.5, 2.0], a)

    a = []
    (0x40000000..0x40000002).step(0.5) {|x| a << x }
    assert_equal([1073741824, 1073741824.5, 1073741825.0, 1073741825.5, 1073741826], a)

    o = Object.new
    def o.to_int() 1 end
    assert_nothing_raised("[ruby-dev:34558]") { (0..2).step(o) {|x| } }

    o = Object.new
    class << o
      def to_str() "a" end
      def <=>(other) to_str <=> other end
    end

    a = []
    (o.."c").step(1) {|x| a << x}
    assert_equal(["a", "b", "c"], a)
    a = []
    (o..).step(1) {|x| a << x; break if a.size >= 3}
    assert_equal(["a", "b", "c"], a)
  end

  def test_percent_step
    aseq = (1..10) % 2
    assert_equal(Enumerator::ArithmeticSequence, aseq.class)
    assert_equal(1, aseq.begin)
    assert_equal(10, aseq.end)
    assert_equal(2, aseq.step)
    assert_equal([1, 3, 5, 7, 9], aseq.to_a)
  end

  def test_step_ruby_core_35753
    assert_equal(6, (1...6.3).step.to_a.size)
    assert_equal(5, (1.1...6).step.to_a.size)
    assert_equal(5, (1...6).step(1.1).to_a.size)
    assert_equal(3, (1.0...5.4).step(1.5).to_a.size)
    assert_equal(3, (1.0...5.5).step(1.5).to_a.size)
    assert_equal(4, (1.0...5.6).step(1.5).to_a.size)
  end

  def test_each
    a = []
    (0..10).each {|x| a << x }
    assert_equal([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], a)

    a = []
    (0..).each {|x| a << x; break if a.size == 10 }
    assert_equal([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], a)

    o1 = Object.new
    o2 = Object.new
    def o1.setcmp(v) @cmpresult = v end
    o1.setcmp(-1)
    def o1.<=>(x); @cmpresult; end
    def o2.setcmp(v) @cmpresult = v end
    o2.setcmp(0)
    def o2.<=>(x); @cmpresult; end
    class << o1; self; end.class_eval do
      define_method(:succ) { o2 }
    end

    r1 = (o1..o2)
    r2 = (o1...o2)

    a = []
    r1.each {|x| a << x }
    assert_equal([o1, o2], a)

    a = []
    r2.each {|x| a << x }
    assert_equal([o1], a)

    o2.setcmp(1)

    a = []
    r1.each {|x| a << x }
    assert_equal([o1], a)

    o2.setcmp(nil)

    a = []
    r1.each {|x| a << x }
    assert_equal([o1], a)

    o1.setcmp(nil)

    a = []
    r2.each {|x| a << x }
    assert_equal([], a)

    o = Object.new
    class << o
      def to_str() "a" end
      def <=>(other) to_str <=> other end
    end

    a = []
    (o.."c").each {|x| a << x}
    assert_equal(["a", "b", "c"], a)
    a = []
    (o..).each {|x| a << x; break if a.size >= 3}
    assert_equal(["a", "b", "c"], a)
  end

  def test_begin_end
    assert_equal(0, (0..1).begin)
    assert_equal(1, (0..1).end)
    assert_equal(1, (0...1).end)
    assert_equal(0, (0..nil).begin)
    assert_equal(nil, (0..nil).end)
    assert_equal(nil, (0...nil).end)
  end

  def test_first_last
    assert_equal([0, 1, 2], (0..10).first(3))
    assert_equal([8, 9, 10], (0..10).last(3))
    assert_equal(0, (0..10).first)
    assert_equal(10, (0..10).last)
    assert_equal("a", ("a".."c").first)
    assert_equal("c", ("a".."c").last)
    assert_equal(0, (2..0).last)

    assert_equal([0, 1, 2], (0...10).first(3))
    assert_equal([7, 8, 9], (0...10).last(3))
    assert_equal(0, (0...10).first)
    assert_equal(10, (0...10).last)
    assert_equal("a", ("a"..."c").first)
    assert_equal("c", ("a"..."c").last)
    assert_equal(0, (2...0).last)

    assert_equal([0, 1, 2], (0..nil).first(3))
    assert_equal(0, (0..nil).first)
    assert_equal("a", ("a"..nil).first)
    assert_raise(RangeError) { (0..nil).last }
    assert_raise(RangeError) { (0..nil).last(3) }

    assert_equal([0, 1, 2], (0..10).first(3.0))
    assert_equal([8, 9, 10], (0..10).last(3.0))
    assert_raise(TypeError) { (0..10).first("3") }
    assert_raise(TypeError) { (0..10).last("3") }
    class << (o = Object.new)
      def to_int; 3; end
    end
    assert_equal([0, 1, 2], (0..10).first(o))
    assert_equal([8, 9, 10], (0..10).last(o))

    assert_raise(ArgumentError) { (0..10).first(-1) }
    assert_raise(ArgumentError) { (0..10).last(-1) }
  end

  def test_to_s
    assert_equal("0..1", (0..1).to_s)
    assert_equal("0...1", (0...1).to_s)
    assert_equal("0..", (0..nil).to_s)
    assert_equal("0...", (0...nil).to_s)

    bug11767 = '[ruby-core:71811] [Bug #11767]'
    assert_predicate(("0".taint.."1").to_s, :tainted?, bug11767)
    assert_predicate(("0".."1".taint).to_s, :tainted?, bug11767)
    assert_predicate(("0".."1").taint.to_s, :tainted?, bug11767)
  end

  def test_inspect
    assert_equal("0..1", (0..1).inspect)
    assert_equal("0...1", (0...1).inspect)
    assert_equal("0..", (0..nil).inspect)
    assert_equal("0...", (0...nil).inspect)

    bug11767 = '[ruby-core:71811] [Bug #11767]'
    assert_predicate(("0".taint.."1").inspect, :tainted?, bug11767)
    assert_predicate(("0".."1".taint).inspect, :tainted?, bug11767)
    assert_predicate(("0".."1").taint.inspect, :tainted?, bug11767)
  end

  def test_eqq
    assert_operator(0..10, :===, 5)
    assert_not_operator(0..10, :===, 11)
    assert_operator(5..nil, :===, 11)
    assert_not_operator(5..nil, :===, 0)
  end

  def test_eqq_time
    bug11113 = '[ruby-core:69052] [Bug #11113]'
    t = Time.now
    assert_nothing_raised(TypeError, bug11113) {
      assert_operator(t..(t+10), :===, t+5)
      assert_operator(t.., :===, t+5)
      assert_not_operator(t.., :===, t-5)
    }
  end

  def test_eqq_non_linear
    bug12003 = '[ruby-core:72908] [Bug #12003]'
    c = Class.new {
      attr_reader :value

      def initialize(value)
        @value = value
      end

      def succ
        self.class.new(@value.succ)
      end

      def ==(other)
        @value == other.value
      end

      def <=>(other)
        @value <=> other.value
      end
    }
    assert_operator(c.new(0)..c.new(10), :===, c.new(5), bug12003)
  end

  def test_eqq_non_iteratable
    k = Class.new do
      include Comparable
      attr_reader :i
      def initialize(i) @i = i; end
      def <=>(o); i <=> o.i; end
    end
    assert_operator(k.new(0)..k.new(2), :===, k.new(1))
  end

  def test_include
    assert_include("a".."z", "c")
    assert_not_include("a".."z", "5")
    assert_include("a"..."z", "y")
    assert_not_include("a"..."z", "z")
    assert_not_include("a".."z", "cc")
    assert_include("a".., "c")
    assert_not_include("a".., "5")
    assert_include(0...10, 5)
    assert_include(5..., 10)
    assert_not_include(5..., 0)
  end

  def test_cover
    assert_operator("a".."z", :cover?, "c")
    assert_not_operator("a".."z", :cover?, "5")
    assert_operator("a"..."z", :cover?, "y")
    assert_not_operator("a"..."z", :cover?, "z")
    assert_operator("a".."z", :cover?, "cc")
    assert_not_operator(5..., :cover?, 0)
    assert_not_operator(5..., :cover?, "a")
    assert_operator(5.., :cover?, 10)

    assert_operator(2..5, :cover?, 2..5)
    assert_operator(2...6, :cover?, 2...6)
    assert_operator(2...6, :cover?, 2..5)
    assert_operator(2..5, :cover?, 2...6)
    assert_operator(2..5, :cover?, 2..4)
    assert_operator(2..5, :cover?, 2...4)
    assert_operator(2..5, :cover?, 2...5)
    assert_operator(2..5, :cover?, 3..5)
    assert_operator(2..5, :cover?, 3..4)
    assert_operator(2..5, :cover?, 3...6)
    assert_operator(2...6, :cover?, 2...5)
    assert_operator(2...6, :cover?, 2..5)
    assert_operator(2..6, :cover?, 2...6)
    assert_operator(2.., :cover?, 2..)
    assert_operator(2.., :cover?, 3..)
    assert_operator(1.., :cover?, 1..10)
    assert_operator(2.0..5.0, :cover?, 2..3)
    assert_operator(2..5, :cover?, 2.0..3.0)
    assert_operator(2..5, :cover?, 2.0...3.0)
    assert_operator(2..5, :cover?, 2.0...5.0)
    assert_operator(2.0..5.0, :cover?, 2.0...3.0)
    assert_operator(2.0..5.0, :cover?, 2.0...5.0)
    assert_operator('aa'..'zz', :cover?, 'aa'...'bb')

    assert_not_operator(2..5, :cover?, 1..5)
    assert_not_operator(2...6, :cover?, 1..5)
    assert_not_operator(2..5, :cover?, 1...6)
    assert_not_operator(1..3, :cover?, 1...6)
    assert_not_operator(2..5, :cover?, 2..6)
    assert_not_operator(2...6, :cover?, 2..6)
    assert_not_operator(2...6, :cover?, 2...7)
    assert_not_operator(2..3, :cover?, 1..4)
    assert_not_operator(1..2, :cover?, 1.0..3.0)
    assert_not_operator(1.0..2.9, :cover?, 1.0..3.0)
    assert_not_operator(1..2, :cover?, 4..3)
    assert_not_operator(2..1, :cover?, 1..2)
    assert_not_operator(1...2, :cover?, 1...3)
    assert_not_operator(2.., :cover?, 1..)
    assert_not_operator(2.., :cover?, 1..10)
    assert_not_operator(1..10, :cover?, 1..)
    assert_not_operator(1..5, :cover?, 3..2)
    assert_not_operator(1..10, :cover?, 3...2)
    assert_not_operator(1..10, :cover?, 3...3)
    assert_not_operator('aa'..'zz', :cover?, 'aa'...'zzz')
    assert_not_operator(1..10, :cover?, 1...10.1)
  end

  def test_beg_len
    o = Object.new
    assert_raise(TypeError) { [][o] }
    class << o; attr_accessor :begin end
    o.begin = -10
    assert_raise(TypeError) { [][o] }
    class << o; attr_accessor :end end
    o.end = 0
    assert_raise(TypeError) { [][o] }
    def o.exclude_end=(v) @exclude_end = v end
    def o.exclude_end?() @exclude_end end
    o.exclude_end = false
    assert_nil([0][o])
    assert_raise(RangeError) { [0][o] = 1 }
    class << o
      private :begin, :end
    end
    o.begin = 10
    o.end = 10
    assert_nil([0][o])
    o.begin = 0
    assert_equal([0], [0][o])
    o.begin = 2
    o.end = 0
    assert_equal([], [0, 1, 2][o])
  end

  class CyclicRange < Range
    def <=>(other); true; end
  end
  def test_cyclic_range_inspect
    o = CyclicRange.allocate
    o.instance_eval { initialize(o, 1) }
    assert_equal("(... .. ...)..1", o.inspect)
  end

  def test_comparison_when_recursive
    x = CyclicRange.allocate; x.send(:initialize, x, 1)
    y = CyclicRange.allocate; y.send(:initialize, y, 1)
    Timeout.timeout(1) {
      assert_equal x, y
      assert_operator x, :eql?, y
    }

    z = CyclicRange.allocate; z.send(:initialize, z, :another)
    Timeout.timeout(1) {
      assert_not_equal x, z
      assert_not_operator x, :eql?, z
    }

    x = CyclicRange.allocate
    y = CyclicRange.allocate
    x.send(:initialize, y, 1)
    y.send(:initialize, x, 1)
    Timeout.timeout(1) {
      assert_equal x, y
      assert_operator x, :eql?, y
    }

    x = CyclicRange.allocate
    z = CyclicRange.allocate
    x.send(:initialize, z, 1)
    z.send(:initialize, x, :other)
    Timeout.timeout(1) {
      assert_not_equal x, z
      assert_not_operator x, :eql?, z
    }
  end

  def test_size
    assert_equal 42, (1..42).size
    assert_equal 41, (1...42).size
    assert_equal 6, (1...6.3).size
    assert_equal 5, (1.1...6).size
    assert_equal 42, (1..42).each.size
    assert_nil ("a"..."z").size

    assert_equal Float::INFINITY, (1...).size
    assert_equal Float::INFINITY, (1.0...).size
    assert_nil ("a"...).size
  end

  def test_bsearch_typechecks_return_values
    assert_raise(TypeError) do
      (1..42).bsearch{ "not ok" }
    end
    c = eval("class C\u{309a 26a1 26c4 1f300};self;end")
    assert_raise_with_message(TypeError, /C\u{309a 26a1 26c4 1f300}/) do
      (1..42).bsearch {c.new}
    end
    assert_equal (1..42).bsearch{}, (1..42).bsearch{false}
  end

  def test_bsearch_with_no_block
    enum = (42...666).bsearch
    assert_nil enum.size
    assert_equal 200, enum.each{|x| x >= 200 }
  end

  def test_bsearch_for_other_numerics
    assert_raise(TypeError) {
      (Rational(-1,2)..Rational(9,4)).bsearch
    }
    assert_raise(TypeError) {
      (BigDecimal('0.5')..BigDecimal('2.25')).bsearch
    }
  end

  def test_bsearch_for_fixnum
    ary = [3, 4, 7, 9, 12]
    assert_equal(0, (0...ary.size).bsearch {|i| ary[i] >= 2 })
    assert_equal(1, (0...ary.size).bsearch {|i| ary[i] >= 4 })
    assert_equal(2, (0...ary.size).bsearch {|i| ary[i] >= 6 })
    assert_equal(3, (0...ary.size).bsearch {|i| ary[i] >= 8 })
    assert_equal(4, (0...ary.size).bsearch {|i| ary[i] >= 10 })
    assert_equal(nil, (0...ary.size).bsearch {|i| ary[i] >= 100 })
    assert_equal(0, (0...ary.size).bsearch {|i| true })
    assert_equal(nil, (0...ary.size).bsearch {|i| false })

    ary = [0, 100, 100, 100, 200]
    assert_equal(1, (0...ary.size).bsearch {|i| ary[i] >= 100 })

    assert_equal(1_000_001, (0...).bsearch {|i| i > 1_000_000 })
  end

  def test_bsearch_for_float
    inf = Float::INFINITY
    assert_in_delta(10.0, (0.0...100.0).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)
    assert_in_delta(10.0, (0.0...inf).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)
    assert_in_delta(-10.0, (-inf..100.0).bsearch {|x| x >= 0 || Math.log(-x / 10) < 0 }, 0.0001)
    assert_in_delta(10.0, (-inf..inf).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)
    assert_equal(nil, (-inf..5).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)

    assert_in_delta(10.0, (-inf.. 10).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)
    assert_equal(nil,     (-inf...10).bsearch {|x| x > 0 && Math.log(x / 10) >= 0 }, 0.0001)

    assert_equal(nil, (-inf..inf).bsearch { false })
    assert_equal(-inf, (-inf..inf).bsearch { true })

    assert_equal(inf, (0..inf).bsearch {|x| x == inf })
    assert_equal(nil, (0...inf).bsearch {|x| x == inf })

    v = (-inf..0).bsearch {|x| x != -inf }
    assert_operator(-Float::MAX, :>=, v)
    assert_operator(-inf, :<, v)

    v = (0.0..1.0).bsearch {|x| x > 0 } # the nearest positive value to 0.0
    assert_in_delta(0, v, 0.0001)
    assert_operator(0, :<, v)
    assert_equal(0.0, (-1.0..0.0).bsearch {|x| x >= 0 })
    assert_equal(nil, (-1.0...0.0).bsearch {|x| x >= 0 })

    v = (0..Float::MAX).bsearch {|x| x >= Float::MAX }
    assert_in_delta(Float::MAX, v)
    assert_equal(nil, v.infinite?)

    v = (0..inf).bsearch {|x| x >= Float::MAX }
    assert_in_delta(Float::MAX, v)
    assert_equal(nil, v.infinite?)

    v = (-Float::MAX..0).bsearch {|x| x > -Float::MAX }
    assert_operator(-Float::MAX, :<, v)
    assert_equal(nil, v.infinite?)

    v = (-inf..0).bsearch {|x| x >= -Float::MAX }
    assert_in_delta(-Float::MAX, v)
    assert_equal(nil, v.infinite?)

    v = (-inf..0).bsearch {|x| x > -Float::MAX }
    assert_operator(-Float::MAX, :<, v)
    assert_equal(nil, v.infinite?)

    assert_in_delta(1.0, (0.0..inf).bsearch {|x| Math.log(x) >= 0 })
    assert_in_delta(7.0, (0.0..10).bsearch {|x| 7.0 - x })

    assert_equal(1_000_000.0.next_float, (0.0..).bsearch {|x| x > 1_000_000 })
  end

  def check_bsearch_values(range, search, a)
    from, to = range.begin, range.end
    cmp = range.exclude_end? ? :< : :<=
    r = nil

    a.for "(0) trivial test" do
      r = Range.new(to, from, range.exclude_end?).bsearch do |x|
        fail "#{to}, #{from}, #{range.exclude_end?}, #{x}"
      end
      assert_nil r

      r = (to...to).bsearch do
        fail
      end
      assert_nil r
    end

    # prepare for others
    yielded = []
    r = range.bsearch do |val|
      yielded << val
      val >= search
    end

    a.for "(1) log test" do
      max = case from
            when Float then 65
            when Integer then Math.log(to-from+(range.exclude_end? ? 0 : 1), 2).to_i + 1
            end
      assert_operator yielded.size, :<=, max
    end

    a.for "(2) coverage test" do
      expect = case
               when search < from
                 from
               when search.send(cmp, to)
                 search
               else
                 nil
               end
      assert_equal expect, r
    end

    a.for "(3) uniqueness test" do
      assert_nil yielded.uniq!
    end

    a.for "(4) end of range test" do
      case
      when range.exclude_end?
        assert_not_include yielded, to
        assert_not_equal r, to
      when search >= to
        assert_include yielded, to
        assert_equal search == to ? to : nil, r
      end
    end

    a.for "(5) start of range test" do
      if search <= from
        assert_include yielded, from
        assert_equal from, r
      end
    end

    a.for "(6) out of range test" do
      yielded.each do |val|
        assert_operator from, :<=, val
        assert_send [val, cmp, to]
      end
    end
  end

  def test_range_bsearch_for_floats
    ints   = [-1 << 100, -123456789, -42, -1, 0, 1, 42, 123456789, 1 << 100]
    floats = [-Float::INFINITY, -Float::MAX, -42.0, -4.2, -Float::EPSILON, -Float::MIN, 0.0, Float::MIN, Float::EPSILON, Math::PI, 4.2, 42.0, Float::MAX, Float::INFINITY]

    all_assertions do |a|
      [ints, floats].each do |values|
        values.combination(2).to_a.product(values).each do |(from, to), search|
          check_bsearch_values(from..to, search, a)
          check_bsearch_values(from...to, search, a)
        end
      end
    end
  end

  def test_bsearch_for_bignum
    bignum = 2**100
    ary = [3, 4, 7, 9, 12]
    assert_equal(bignum + 0, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 2 })
    assert_equal(bignum + 1, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 4 })
    assert_equal(bignum + 2, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 6 })
    assert_equal(bignum + 3, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 8 })
    assert_equal(bignum + 4, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 10 })
    assert_equal(nil, (bignum...bignum+ary.size).bsearch {|i| ary[i - bignum] >= 100 })
    assert_equal(bignum + 0, (bignum...bignum+ary.size).bsearch {|i| true })
    assert_equal(nil, (bignum...bignum+ary.size).bsearch {|i| false })
    assert_equal(bignum * 2 + 1, (bignum...).bsearch {|i| i > bignum * 2 })

    assert_raise(TypeError) { ("a".."z").bsearch {} }
  end

  def test_each_no_blockarg
    a = "a"
    def a.upto(x, e, &b)
      super {|y| b.call(y) {|z| assert(false)}}
    end
    (a.."c").each {|x, &b| assert_nil(b)}
  end

  def test_to_a
    assert_equal([1,2,3,4,5], (1..5).to_a)
    assert_equal([1,2,3,4], (1...5).to_a)
    assert_raise(RangeError) { (1..).to_a }
  end
end