How to go about testing decision-state in Spring WebFlow

Question

I'm trying to find the best way to unit test decision-states within a Spring WebFlow context.

<var name="registration" class="*some class path*.Registration"/>

<decision-state id="checkSignedIn">
    <if test="*someClass*.isSignedOn(registration)"
        then="checkHas*Said*Service"
        else="registrationChoice"/>
</decision-state>

<decision-state id="checkHasTCloudService">
    <if test="*someClass*Dao.isUserRegisteredFor*saidSvc*(registration)"
        then="*svc*Activated"
        else="registrationChoice"/>
</decision-state>

<view-state id="registrationChoice" model="registration" view="view.xhtml" >

    <on-entry>...

NB the someClass and the someClassDao are not within the FlowScope or ConversationScope.

I want to test, via Mockito, that the decision-state expressions are being called and then verify the correct state outcomes.

Normally, one can simply

1. setCurrentState(someViewState: where you want slot test in within a transitional flow)
2. define input
3. mock an ExternalContext
4. setEvent within that context
5. resumeFlow(with given context)
6. verify mocked method calls & finally
7. assertCurrentState(someViewState: where you would expect to be at, after given input has influenced the decision-state to fork to, within the flow)

It seems decision-states don't operate as a view-state (fair enough: they aren't a given state of view within a flow) so how are we to mock/test?

Thanks in aniticiptation of responses.

Answer 1

Well, I've been put in the right direction by a colleague (the venerable Murray MacPherson) who reminded me that the process is:
1. mock your dao calls
2. begin your flow & (now this is the crux)
3. based on the decision outcomes set by your mocked calls, assert your expected outcome state (which will be some view),
- whether an end state (in which case you would also be expecting an end to your flow) or
- (interim) current state. If it has arrived at exp[ected point, then you know the decisions have been exercised.

---

NB if your expected outcome is a 'currentState', then you can verify the mocked (dao) call/s has/have been made otherwise (as the flow would no longer be active) you cannot make such verifications: the simple fact you've arrived at your expected end state is verification in itself.

Answer 2

In this exact example, you have an alternative to starting at a particular view state via setCurrentState() - you can use startFlow - which will... start the flow. You can then test which view state you end up at, due to the results of your decision states.