require 'spec_helper' describe IgnorableColumn do let :base_class do Class.new do def self.columns # This method does not have access to "double" [ Struct.new(:name).new('id'), Struct.new(:name).new('title'), Struct.new(:name).new('date') ] end end end let :model do Class.new(base_class) do include IgnorableColumn end end describe '.columns' do it 'returns the columns, excluding the ignored ones' do model.ignore_column(:title, :date) expect(model.columns.map(&:name)).to eq(%w(id)) end end describe '.ignored_columns' do it 'returns a Set' do expect(model.ignored_columns).to be_an_instance_of(Set) end it 'returns the names of the ignored columns' do model.ignore_column(:title, :date) expect(model.ignored_columns).to eq(Set.new(%w(title date))) end end end