How to test message expectations?

[JeanMertz]

I was wondering how I should test message expectations using should_receive with rspec-given?

Here's an example I have:

    context 'persists correct signup data' do
      Given do
        subject.params = { signup: build(:signup).attributes }
        subject.signup.stub(:persist!)
      end

      When { subject.call }
      Then { subject.signup.should_receive(:save).and_return(true) }
    end

This fails for not receiving the message.

       (#<Signup:0x007fb4598206a8>).save(any args)
           expected: 1 time
           received: 0 times

I know the method is being called, because I used to check expect{ subject.call }.to change{ User.count }, but I'd like to rewrite the spec to never hit the database.

I wonder if it's because I am misusing rspec-given in this case? The reason I ask is that I call the method in the When clause, and after that set the expectation in the Then clause. This seems counter to I normally write it in RSpec (first an expectation, then the action).

[cpuguy83]

I think you are not doing something right. It looks like you are testing that a stubbed method returns true... Which in this case you haven't told it to, and would be pointless to test this because you are trying to test a stubbed method.

I would say do not worry about testing persistence. If you merely test that the record is valid you can assume it will persist... "foo.should be_valid"

[jimweirich]

What mocking framework are you using? With most mock libraries, you have to setup the expectations before the When code is run (i.e. in a Given or before block).

If want to check expectations in a Then clause, then you need to use a mock framework that supports spies. Flexmock will support spies. I've heard that RSpec mocks also support them (or will soon? I don't have details).

See https://github.com/jimweirich/flexmock#spies for details on using spies with flexmock.

[JeanMertz]

It looks like you are testing that a stubbed method returns true

No, I haven't stubbed save, I've only stubbed persist! (so it doesn't touch the database). This is not a standard AR model, so that's why I want to test if save is called correctly.

However, I'm not quite sure if I can use should_receive on a non-stubbed method. I'm not even sure if I've written the correct expectation using the default rspec mocks.

Anyway, thank you for your responses, I will continue investigating why this fails.

[jimweirich]

Looks like spies will be in RSpec 2.14 (which isn't out yet). In the meantime, you can try out https://github.com/technicalpickles/rspec-spies