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path: root/spec/ruby/core/enumerator/lazy/uniq_spec.rb
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require_relative '../../../spec_helper'
require_relative 'fixtures/classes'

describe 'Enumerator::Lazy#uniq' do
  context 'without block' do
    before :each do
      @lazy = [0, 1, 0, 1].to_enum.lazy.uniq
    end

    it 'returns a lazy enumerator' do
      @lazy.should be_an_instance_of(Enumerator::Lazy)
      @lazy.force.should == [0, 1]
    end

    it 'return same value after rewind' do
      @lazy.force.should == [0, 1]
      @lazy.force.should == [0, 1]
    end

    it 'sets the size to nil' do
      @lazy.size.should == nil
    end
  end

  context 'when yielded with an argument' do
    before :each do
      @lazy = [0, 1, 2, 3].to_enum.lazy.uniq(&:even?)
    end

    it 'returns a lazy enumerator' do
      @lazy.should be_an_instance_of(Enumerator::Lazy)
      @lazy.force.should == [0, 1]
    end

    it 'return same value after rewind' do
      @lazy.force.should == [0, 1]
      @lazy.force.should == [0, 1]
    end

    it 'sets the size to nil' do
      @lazy.size.should == nil
    end
  end

  context 'when yielded with multiple arguments' do
    before :each do
      enum = Object.new.to_enum
      class << enum
        def each
          yield 0, 'foo'
          yield 1, 'FOO'
          yield 2, 'bar'
        end
      end
      @lazy = enum.lazy
    end

    it 'return same value after rewind' do
      enum = @lazy.uniq { |_, label| label.downcase }
      enum.force.should == [[0, 'foo'], [2, 'bar']]
      enum.force.should == [[0, 'foo'], [2, 'bar']]
    end

    it 'returns all yield arguments as an array' do
      @lazy.uniq { |_, label| label.downcase }.force.should == [[0, 'foo'], [2, 'bar']]
    end
  end

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