require "spec_helper" describe "a double receiving to_ary" do shared_examples "to_ary" do it "returns nil" do expect do expect(obj.to_ary).to be_nil end.to raise_error(NoMethodError) end it "doesn't respond" do expect(obj).not_to respond_to(:to_ary) end it "can be overridden with a stub" do Spy.on(obj, :to_ary) { :non_nil_value } expect(obj.to_ary).to be(:non_nil_value) end it "responds when overriden" do Spy.on(obj, :to_ary) { :non_nil_value } expect(obj).to respond_to(:to_ary) end it "supports Array#flatten" do obj = double('foo') expect([obj].flatten).to eq([obj]) end end context "double as_null_object" do let(:obj) { double('obj').as_null_object } include_examples "to_ary" end context "double without as_null_object" do let(:obj) { double('obj') } include_examples "to_ary" end end