Feature: Expect error Expect a proc to raise an error when called. Scenario: expect error Given a file named "expect_error_spec.rb" with: """ describe Object, "#non_existent_message" do it "should raise" do expect{Object.non_existent_message}.to raise_error(NameError) end end #deliberate failure describe Object, "#public_instance_methods" do it "should raise" do expect{Object.public_instance_methods}.to raise_error(NameError) end end """ When I run "rspec ./expect_error_spec.rb" Then the output should contain "2 examples, 1 failure" Then the output should contain "expected NameError but nothing was raised" Scenario: expect no error Given a file named "expect_no_error_spec.rb" with: """ describe Object, "#public_instance_methods" do it "should not raise" do expect{Object.public_instance_methods}.to_not raise_error(NameError) end end #deliberate failure describe Object, "#non_existent_message" do it "should not raise" do expect{Object.non_existent_message}.to_not raise_error(NameError) end end """ When I run "rspec ./expect_no_error_spec.rb" Then the output should contain "2 examples, 1 failure" Then the output should contain "undefined method `non_existent_message'"