require 'spec_helper'

module Arel
  module Predicates
    describe Equality do
      before do
        @relation1 = Arel::Table.new(:users)
        @relation2 = Arel::Table.new(:photos)
        @attribute1 = @relation1[:id]
        @attribute2 = @relation2[:user_id]
      end

      describe '==' do
        it "obtains if attribute1 and attribute2 are identical" do
          check Equality.new(@attribute1, @attribute2).should == Equality.new(@attribute1, @attribute2)
          Equality.new(@attribute1, @attribute2).should_not == Equality.new(@attribute1, @attribute1)
        end

        it "obtains if the concrete type of the predicates are identical" do
          Equality.new(@attribute1, @attribute2).should_not == Binary.new(@attribute1, @attribute2)
        end

        it "is commutative on the attributes" do
          Equality.new(@attribute1, @attribute2).should == Equality.new(@attribute2, @attribute1)
        end
      end
    end
  end
end