ruby--ruby/spec/ruby/core/enumerable/uniq_spec.rb

require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)

ruby_version_is '2.4' do
  describe 'Enumerable#uniq' do
    it 'returns an array that contains only unique elements' do
      [0, 1, 2, 3].to_enum.uniq { |n| n.even? }.should == [0, 1]
    end

    it "uses eql? semantics" do
      [1.0, 1].to_enum.uniq.should == [1.0, 1]
    end

    it "compares elements first with hash" do
      x = mock('0')
      x.should_receive(:hash).at_least(1).and_return(0)
      y = mock('0')
      y.should_receive(:hash).at_least(1).and_return(0)

      [x, y].to_enum.uniq.should == [x, y]
    end

    it "does not compare elements with different hash codes via eql?" do
      x = mock('0')
      x.should_not_receive(:eql?)
      y = mock('1')
      y.should_not_receive(:eql?)

      x.should_receive(:hash).at_least(1).and_return(0)
      y.should_receive(:hash).at_least(1).and_return(1)

      [x, y].to_enum.uniq.should == [x, y]
    end

    it "compares elements with matching hash codes with #eql?" do
      a = Array.new(2) do
        obj = mock('0')
        obj.should_receive(:hash).at_least(1).and_return(0)

        def obj.eql?(o)
          # It's undefined whether the impl does a[0].eql?(a[1]) or
          # a[1].eql?(a[0]) so we taint both.
          taint
          o.taint
          false
        end

        obj
      end

      a.uniq.should == a
      a[0].tainted?.should == true
      a[1].tainted?.should == true

      a = Array.new(2) do
        obj = mock('0')
        obj.should_receive(:hash).at_least(1).and_return(0)

        def obj.eql?(o)
          # It's undefined whether the impl does a[0].eql?(a[1]) or
          # a[1].eql?(a[0]) so we taint both.
          taint
          o.taint
          true
        end

        obj
      end

      a.to_enum.uniq.size.should == 1
      a[0].tainted?.should == true
      a[1].tainted?.should == true
    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
      end

      ruby_bug '#13669', ''...'2.5' do
        it 'returns all yield arguments as an array' do
          @enum.uniq { |_, label| label.downcase }.should == [[0, 'foo'], [2, 'bar']]
        end
      end
    end
  end
end