# -*- encoding: us-ascii -*-

require_relative '../../../spec_helper'
require_relative 'fixtures/classes'

describe "Enumerator::Lazy#zip" do
  before :each do
    @yieldsmixed = EnumeratorLazySpecs::YieldsMixed.new.to_enum.lazy
    @eventsmixed = EnumeratorLazySpecs::EventsMixed.new.to_enum.lazy
    ScratchPad.record []
  end

  after :each do
    ScratchPad.clear
  end

  it "returns a new instance of Enumerator::Lazy" do
    ret = @yieldsmixed.zip []
    ret.should.instance_of?(Enumerator::Lazy)
    ret.should_not.equal?(@yieldsmixed)
  end

  it "keeps size" do
    Enumerator::Lazy.new(Object.new, 100) {}.zip([], []).size.should == 100
  end

  describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
    it "stops after specified times" do
      (0..Float::INFINITY).lazy.zip([4, 5], [8]).first(2).should == [[0, 4, 8], [1, 5, nil]]

      @eventsmixed.zip([0, 1]).first(1)
      ScratchPad.recorded.should == [:before_yield]
    end
  end

  it "calls the block with a gathered array when yield with multiple arguments" do
    yields = @yieldsmixed.zip(EnumeratorLazySpecs::YieldsMixed.new.to_enum).force
    yields.should == [EnumeratorLazySpecs::YieldsMixed.gathered_yields,
                      EnumeratorLazySpecs::YieldsMixed.gathered_yields].transpose
  end

  it "returns a Lazy when no arguments given" do
    @yieldsmixed.zip.should.instance_of?(Enumerator::Lazy)
  end

  it "raises a TypeError if arguments contain non-list object" do
    -> { @yieldsmixed.zip [], Object.new, [] }.should.raise(TypeError)
  end

  describe "when the returned lazy enumerator is evaluated by .force" do
    it "return same value when called twice" do
      lazy = [0, 1].lazy.zip([2, 3])
      lazy.force.should == [[0, 2], [1, 3]]
      lazy.force.should == [[0, 2], [1, 3]]
    end
  end

  describe "on a nested Lazy" do
    it "keeps size" do
      Enumerator::Lazy.new(Object.new, 100) {}.map {}.zip([], []).size.should == 100
    end

    it "behaves as Enumerable#zip when given a block" do
      lazy_yields = []
      lazy_ret = @yieldsmixed.zip(EnumeratorLazySpecs::YieldsMixed.new.to_enum) { |lists| lazy_yields << lists }
      enum_yields = []
      enum_ret = EnumeratorLazySpecs::YieldsMixed.new.to_enum.zip(EnumeratorLazySpecs::YieldsMixed.new.to_enum) { |lists| enum_yields << lists }

      lazy_yields.should == enum_yields
      lazy_ret.should == enum_ret
    end

    describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
      it "stops after specified times" do
        (0..Float::INFINITY).lazy.map(&:succ).zip([4, 5], [8]).first(2).should == [[1, 4, 8], [2, 5, nil]]

        @eventsmixed.zip([0, 1]).zip([0, 1]).first(1)
        ScratchPad.recorded.should == [:before_yield]
      end
    end
  end

  it "works with an infinite enumerable and an array" do
    s = 0..Float::INFINITY
    s.lazy.zip(0..1000).first(100).should ==
      s.first(100).zip(0..100)
  end

  it "works with two infinite enumerables" do
    s = 0..Float::INFINITY
    s.lazy.zip(s).first(100).should ==
      s.first(100).zip(s)
  end
end
