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

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

    describe '#to_sql' do
      describe 'when relating to a non-nil value' do
        it "manufactures an equality predicate" do
          sql = Equality.new(@attribute1, @attribute2).to_sql

          adapter_is :mysql do
            sql.should be_like(%Q{`users`.`id` = `photos`.`user_id`})
          end

          adapter_is_not :mysql do
            sql.should be_like(%Q{"users"."id" = "photos"."user_id"})
          end
        end
      end

      describe 'when relation to a nil value' do
        before do
          @nil = nil
        end

        it "manufactures an is null predicate" do
          sql = Equality.new(@attribute1, @nil).to_sql

          adapter_is :mysql do
            sql.should be_like(%Q{`users`.`id` IS NULL})
          end

          adapter_is_not :mysql do
            sql.should be_like(%Q{"users"."id" IS NULL})
          end
        end
      end
    end
  end
end