require 'spec_helper' module Arel describe Table do before do @relation = Table.new(:users) end describe '[]' do describe 'when given a', Symbol do it "manufactures an attribute if the symbol names an attribute within the relation" do @relation[:id].should == Attribute.new(@relation, :id) @relation[:does_not_exist].should be_nil end end describe 'when given an', Attribute do it "returns the attribute if the attribute is within the relation" do @relation[@relation[:id]].should == @relation[:id] end it "returns nil if the attribtue is not within the relation" do another_relation = Table.new(:photos) @relation[another_relation[:id]].should be_nil end end describe 'when given an', Expression do before do @expression = @relation[:id].count end it "returns the Expression if the Expression is within the relation" do @relation[@expression].should be_nil end end end end end