Search code examples
c#bddstoryq

StoryQ BDD, Given or When without a body

I would like to do a very simple test for the Constructor of my class,

[Test]
public void InitLensShadingPluginTest()
{
    _lensShadingStory.WithScenario("Init Lens Shading plug-in")
        .Given(InitLensShadingPlugin)
        .When(Nothing)
        .Then(PluginIsCreated)
        .Execute();
}

this can be in Given or When it... I think it should be in When() but it doesn't really matter.

private void InitLensShadingPlugin()
{
    _plugin = new LSCPlugin(_imagesDatabaseProvider, n_iExternalToolImageViewerControl);
}

Since the Constructor is the one being tested, I do not have anything to do inside the When() statement,

And in Then() I assert about the plugin creation.

private void PluginIsCreated()
{
    Assert.NotNull(_plugin);
}

my question is about StoryQ, since I do not want to do anything inside When() i tried to use When(()=>{}) however this is not supported by storyQ, this means I need to implement something like 

private void Nothing()
{
}

and call When(Nothing)

is there a better practice?

Solution

  • It's strange that StoryQ doesn't support missing steps; your scenario is actually pretty typical of other examples I've used of starting applications, games etc. up:

    Given the chess program is running
Then the pieces should be in the starting positions

    for instance. So your desire to use a condition followed by an outcome is perfectly valid.

    Looking at StoryQ's API, it doesn't look as if it supports these empty steps. You could always make your own method and call both the Given and When steps inside it, returning the operation from the When:

        .GivenIStartedWith(InitLensShadingPlugin)
    .Then(PluginIsCreated)

    If that seems too clunky, I'd do as you suggested and move the Given to a When, initializing the Given with an empty method with a more meaningful name instead:

        Given(NothingIsInitializedYet)
    .When(InitLensShadingPlugin)
    .Then(PluginIsCreated)

    Either of these will solve your problem.

    However, if all you're testing is a class, rather than an entire application, using StoryQ is probably overkill. The natural-language BDD frameworks like StoryQ, Cucumber, JBehave etc. are intended to help business and development teams collaborate in their exploration of requirements. They incur significant setup and maintenance overhead, so if the audience of your class-level scenarios / examples is technical, there may be an easier way.

    For class-level examples of behaviour I would just go with a plain unit testing tool like NUnit or MSpec. I like using NUnit and putting my "Given / When / Then" in comments:

    // Given I initialized the lens shading plugin on startup
_plugin = new LSCPlugin(_imagesDatabaseProvider, n_iExternalToolImageViewerControl);    

// Then the plugin should have been created
Assert.NotNull(_plugin);

    Steps at a class level aren't reused in the same way they are in full-system scenarios, because classes have much smaller, more encapsulated responsibilities; and developers benefit from reading the code rather than having it hidden away in the step definitions.

    Your Given/When/Then comments here might still echo scenarios at a higher level, if the class is directly driving the functionality that the user sees.

    Normally for full-system scenarios we would derive the steps from conversations with the "3 amigos":

    • a business representative (PO, SME, someone who has a problem to be solved)
    • a tester (who spots scenarios we might otherwise miss)
    • the dev (who's going to solve the problem).

    There might be a pair of devs. UI designers can get involved if they want to. Matt Wynne says it's "3 amigos, where 3 is any number between 3 and 7". The best time to have the conversations is right before the devs pick up the work to begin coding it.

    However, if you're working on your own, whether it's a toy or a real application, you might benefit just from having imaginary conversations. I use a pixie called Thistle for mine.