spec/arel/algebra/unit/relations/join_spec.rb


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require File.join(File.dirname(__FILE__), '..', '..', '..', '..', 'spec_helper')

module Arel
  describe Join do
    before do
      @relation1 = Table.new(:users)
      @relation2 = Table.new(:photos)
      @predicate = @relation1[:id].eq(@relation2[:user_id])
    end
    
    describe 'hashing' do
      it 'implements hash equality' do
        InnerJoin.new(@relation1, @relation2, @predicate) \
          .should hash_the_same_as(InnerJoin.new(@relation1, @relation2, @predicate))
      end
    end
    
    describe '#attributes' do
      it 'combines the attributes of the two relations' do
        join = InnerJoin.new(@relation1, @relation2, @predicate)
        join.attributes.should ==
          (@relation1.attributes + @relation2.attributes).collect { |a| a.bind(join) }
      end
    end
  end
end