Session variables with Cucumber Stories

Question

I am working on some Cucumber stories for a 'sign up' application which has a number of steps.

Rather then writing a Huuuuuuuge story to cover all the steps at once, which would be bad, I'd rather work through each action in the controller like a regular user. My problem here is that I am storing the account ID which is created in the first step as a session variable, so when step 2, step 3 etc are visited the existing registration data is loaded.

I'm aware of being able to access controller.session[..] within RSpec specifications however when I try to do this in Cucumber stories it fails with the following error (and, I've also read somewhere this is an anti-pattern etc...):

Using controller.session[:whatever] or session[:whatever]

You have a nil object when you didn't expect it!
The error occurred while evaluating nil.session (NoMethodError)

Using session(:whatever)

wrong number of arguments (1 for 0) (ArgumentError)

So, it seems accession the session store isn't really possible. What I'm wondering is if it might be possible to (and I guess which would be best..):

1. Mock out the session store etc
2. Have a method within the controller and stub that out (e.g. get_registration which assigns an instance variable...)

I've looked through the RSpec book (well, skimmed) and had a look through WebRat etc, but I haven't really found an answer to my problem...

To clarify a bit more, the signup process is more like a state machine - e.g. the user progresses through four steps before the registration is complete - hence 'logging in' isn't really an option (it breaks the model of how the site works)...

In my spec for the controller I was able to stub out the call to the method which loads the model based on the session var - but I'm not sure if the 'antipattern' line also applies to stubs as well as mocks?

Thanks!

Answer 1

mocks are bad in cucumber scenarios - they're almost kind of an antipattern.

My suggestion is to write a step that actually logs a user in. I do it this way

Given I am logged in as "[email protected]"

Given /^I am logged in as "(.*)"$/ do |email|
  @user = Factory(:user, :email => email)
  @user.activate!
  visit("/session/new")
  fill_in("email", :with => @user.email)
  fill_in("password", :with => @user.password)
  click_button("Sign In")
end

I realize that the instance variable @user is kind of bad form, but I think in the case of logging in, logging out having that @user var is definitely helpful. Sometimes I'll call is @current_user

Answer 2

I'll repeat danpickett in saying mocks should be avoided whenever possible in Cucumber. However if your app does not have a login page, or perhaps performance is a problem, then it may be necessary to simulate login directly.

This is an ugly hack, but it should get the job done.

Given /^I am logged in as "(.*)"$/ do |email|
  @current_user = Factory(:user, :email => email)
  cookies[:stub_user_id] = @current_user.id
end

# in application controller
class ApplicationController < ActionController::Base
  if Rails.env.test?
    prepend_before_filter :stub_current_user
    def stub_current_user
      session[:user_id] = cookies[:stub_user_id] if cookies[:stub_user_id]
    end
  end
end

Answer 3

My understanding is that you get:

You have a nil object when you didn't expect it!
The error occurred while evaluating nil.session (NoMethodError)

when session[] is accessed before request has been instantiated. In your case, I'd imagine if you put webrats' visit some_existing_path before accessing session[] in your step defenition, the error will go away.

Now, unfortunately, session doesn't seem to persist across steps (at least, I couldn't find the way), so this bit of information doesn't help to answer your question :)

So, I suppose, Ryan's session[:user_id] = cookies[:stub_user_id]... is the way to go. Although, imo, test related code in the application itself doesn't sound right.

Answer 4

I don't know how much this relates to the original question anymore, but I decided to post anyway in the spirit of discussion...

We have a cucumber test suite that takes > 10 minutes to run so we wanted to do some optimization. In our app the login process triggers a LOT of extra functionality that is irrelevant to majority of the scenarios, so we wanted to skip that by setting the session user id directly.

Ryanb's approach above worked nicely, except that we were unable to log out using that approach. This made our multi-user stories fail.

We ended up creating a "quick login" route that is only enabled in test environment:

# in routes.rb
map.connect '/quick_login/:login', :controller => 'logins', :action => 'quick_login'

Here is the corresponding action that creates the session variable:

# in logins_controller.rb
class LoginsController < ApplicationController
  # This is a utility method for selenium/webrat tests to speed up & simplify the process of logging in.
  # Please never make this method usable in production/staging environments.
  def quick_login
    raise "quick login only works in cucumber environment! it's meant for acceptance tests only" unless Rails.env.test?
    u = User.find_by_login(params[:login])
    if u
      session[:user_id] = u.id
      render :text => "assumed identity of #{u.login}"
    else
      raise "failed to assume identity"
    end
  end
end

For us this ended up being simpler than working with the cookies array. As a bonus, this approach also works with Selenium/Watir.

Downside is that we're including test-related code in our application. Personally I don't think that adding code to make application more testable is a huge sin, even if it does add a bit of clutter. Perhaps the biggest problem is that future test authors need to figure out which type of login they should use. With unlimited hardware performance we obviously wouldn't be doing any of this.

Answer 5

Re. Ryan's solution - you can open up ActionController in you env.rb file and place it there to avoid putting in your production code base (thanks to john @ pivotal labs)

# in features/support/env.rb
class ApplicationController < ActionController::Base
  prepend_before_filter :stub_current_user
  def stub_current_user
    session[:user_id] = cookies[:stub_user_id] if cookies[:stub_user_id]
  end
end

Answer 6

I use a testing-only sign-in solution like Prikka's, but I do it all in Rack instead of creating a new Controller and routes.

# in config/environments/cucumber.rb:

config.middleware.use (Class.new do
  def initialize(app); @app = app; end
  def call(env)
    request = ::Rack::Request.new(env)
    if request.params.has_key?('signed_in_user_id')
      request.session[:current_user_id] = request.params['signed_in_user_id']
    end
    @app.call env
  end
end)

# in features/step_definitions/authentication_steps.rb:
Given /^I am signed in as ([^\"]+)$/ do |name|
  user = User.find_by_username(name) || Factory(:user, :username => name)
  sign_in_as user
end

# in features/step_definitions/authentication_steps.rb:
Given /^I am not signed in$/ do
  sign_in_as nil
end

module AuthenticationHelpers
  def sign_in_as(user)
    return if @current_user == user
    @current_user = user
    get '/', { 'signed_in_user_id' => (user ? user.to_param : '') }
  end
end

World(AuthenticationHelpers)