obj.should ... expect(obj).to ... obj.should_not ... expect(obj).not_to ... obj.should =~ // expect(obj).to match(//) [1, 2, 3].should =~ [3, 2, 1] expect([1, 2, 3]).to match_array([3, 2, 1]) obj.should > 3 expect(obj).to be > 3 lambda { ... }.should raise_error expect { ... }.to raise_error # RSpec 2.14.0 or later obj.stub(:foo) allow(obj).to receive(:foo) SomeClass.any_instance.should_receive(:f