in which I try to get done with my mockamator already by writing stories describing what it should do, learning how to work with Story Runner in RSpec along the way.

references:
* What’s in a Story by Dan North
* Great step by step example driven tutorial for Rspec on story runner
* RSpec docs on mock objects

This is my first attempt at a story. I already find this helpful as it forces me to make decisions and figure out what it is, exactly, that I’m trying to accomplish. And how.

The Nelson plugin should automagically create mocks (valid or invalid) for any given controller

Narrative:

As a developer
I want to easily write controller specs
So that I’m not spending hours on hundreds of LOC making mocks with the right expectations

Acceptance Criteria:

Scenario 1: writing a new controller spec
Given the UserController
   And that I want to use valid mocks that won’t throw errors
When calling Nelson.generate_mocks(UserController, {:valid => true})
Then a site instance object should be mocked out
   And a get request, for example, on the signup form should not raise an error

Ok, so that’s my story and it’s useful in that it’s already helped me get a better idea of what I’m doing… but how do I translate this into Ruby code that can be run through rspec?

One of the tutorials I’m following gives an example of a story, so I am just going to copy and paste it and change it to be appropriate for my narrative:

   1  Story "The Nelson plugin", %{
   2    should automagically create mocks 
   3    that are valid or invalid
   4    for any given controller
   5  }, :type => RailsStory do
   6  
   7    Scenario "in the before block of a controller spec" do
   8      When "calling Nelson.generate_mocks" do
   9        Nelson.generate_mocks(UserController, {:valid => true})
  10      end
  11  
  12      Then "a site mock should be generated" do
  13        @site.should_not be_nil
  14        @site.should be_a_kind_of(Site)
  15      end
  16  
  17      When "I request the UserController signup action in a get request" do
  18        get '/user/signup'
  19      end
  20  
  21      Then "response should be successful" do 
  22        response.should be_success
  23      end 
  24    end
  25  end

That was my first attempt. While writing this a few questions came up, namely…

- does the context get preserved between different When events? that is, will instance variables that are created in one event be accessible in a subsequent event context?
- am i breaking up my tasks correctly?
- what’s up with that array of phrases in the Story block anyway?
- does the When have to be mapped to a controller request?
    (from the vaporbase.com tutorial: “The “When” clause is the meat of the scenario. It is a controller action, and its spec gets done next… “)

Only one way to find out: time to run this through the story runner. I foresee some errors… :)

   1  jm:~/se/app/workspace (master) $ ruby stories/nelson_should_create_mocks.rb 
   2  Running 1 scenarios
   3  
   4  Story: The Nelson plugin
   5  
   6    
   7      should automagically create mocks 
   8      that are valid or invalid
   9      for any given controller
  10  
  11  
  12    Scenario: in the before block of a controller spec
  13  
  14      When calling Nelson.generate_mocks (FAILED)
  15  
  16      Then a site mock should be generated (SKIPPED)
  17  
  18      When I request the UserController signup action in a get request
  19  
  20      Then response should be successful
  21  
  22  1 scenarios: 0 succeeded, 1 failed, 0 pending
  23  
  24  FAILURES:
  25      1) The Nelson plugin (in the before block of a controller spec) FAILED
  26      NoMethodError: undefined method `generate_mocks' for Nelson:Class
  27      stories/nelson_should_create_mocks.rb:28:in `calling Nelson.generate_mocks'
  28  stories/nelson_should_create_mocks.rb:27
  29  stories/nelson_should_create_mocks.rb:20

Whoa! That actually went a lot better than I expected. I haven’t written the method “generate_mocks” in my plugin yet, so naturally it would fail.

I love the output of the Story Runner. I think I might be sold. Time to write the methods in my Nelson plugin that will generate the mocks, I guess.

I’ll be posting my stories - when they’re closer to being finalized - here as examples for other people to reference.

In the meantime, here are some:

* from pastie
* from evang.eli.st (scroll down)
* plain text stories from david chelimsky’s blog