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path: root/spec/ruby/core/enumerator/lazy/grep_v_spec.rb
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require File.expand_path('../../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)

ruby_version_is "2.3" do
  describe "Enumerator::Lazy#grep_v" 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 "requires an argument" do
      Enumerator::Lazy.instance_method(:grep_v).arity.should == 1
    end

    it "returns a new instance of Enumerator::Lazy" do
      ret = @yieldsmixed.grep_v(Object) {}
      ret.should be_an_instance_of(Enumerator::Lazy)
      ret.should_not equal(@yieldsmixed)

      ret = @yieldsmixed.grep_v(Object)
      ret.should be_an_instance_of(Enumerator::Lazy)
      ret.should_not equal(@yieldsmixed)
    end

    it "sets #size to nil" do
      Enumerator::Lazy.new(Object.new, 100) {}.grep_v(Object) {}.size.should == nil
      Enumerator::Lazy.new(Object.new, 100) {}.grep_v(Object).size.should == nil
    end

    describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
      it "stops after specified times when not given a block" do
        (0..Float::INFINITY).lazy.grep_v(3..5).first(3).should == [0, 1, 2]

        @eventsmixed.grep_v(Symbol).first(1)
        ScratchPad.recorded.should == [:before_yield]
      end

      it "stops after specified times when given a block" do
        (0..Float::INFINITY).lazy.grep_v(4..8, &:succ).first(3).should == [1, 2, 3]

        @eventsmixed.grep_v(Symbol) {}.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.grep_v(Array) { |v| yields << v }.force
      yields.should == EnumeratorLazySpecs::YieldsMixed.gathered_non_array_yields

      @yieldsmixed.grep_v(Array).force.should == yields
    end

    describe "on a nested Lazy" do
      it "sets #size to nil" do
        Enumerator::Lazy.new(Object.new, 100) {}.grep_v(Object).grep_v(Object) {}.size.should == nil
        Enumerator::Lazy.new(Object.new, 100) {}.grep_v(Object).grep_v(Object).size.should == nil
      end

      describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
        it "stops after specified times when not given a block" do
          (0..Float::INFINITY).lazy.grep_v(3..5).grep_v(6..10).first(3).should == [0, 1, 2]

          @eventsmixed.grep_v(Symbol).grep_v(String).first(1)
          ScratchPad.recorded.should == [:before_yield]
        end

        it "stops after specified times when given a block" do
          (0..Float::INFINITY).lazy
            .grep_v(1..2) { |n| n > 3 ? n : false }
            .grep_v(false) { |n| n.even? ? n : false }
            .first(3)
            .should == [4, false, 6]

          @eventsmixed.grep_v(Symbol) {}.grep_v(String) {}.first(1)
          ScratchPad.recorded.should == [:before_yield]
        end
      end
    end
  end
end