Outside-In Development With Cucumber

Outside-In
Development
With

Ben Mabey
Saturday, March 14, 2009

Who’s my
audience?


Scenario: planning meeting
Given I am a Software Developer
When I am given a feature request
Then I should...


What is the most
CRITICAL
word to keep in mind?


Scenario: planning meeting
Given I am a Software Developer
When I am given a feature request
Then I should ask why.


_why


Feature Request:
Print Reports
Story from
Thought works:

http://
www.theregister.co.uk/
2007 /06/25/


Protect Revenue

Increase Revenue

Manage Cost


* not executed
* documentation value

Feature: title * variant of contextra
* business value up front

In order to [Business Value]
As a [Role]
I want to [Some Action] (feature)


There is no template.
What is important to
have in narrative:

* business value
* stakeholder role
* user role
* action to be taken by
user


Scenario: title
Given [Context]
When I do [Action]
Then I should see [Outcome]


Scenario: title
Given [Context]
And [More Context]
When I do [Action]
And [Other Action]
Then I should see [Outcome]
But I should not see [Outcome]


project_root/
|
`-- features


project_root/
|
`-- features
|-- awesomeness.feature
|-- greatest_ever.feature


project_root/
|
`-- features
`-- support
|-- env.rb
`-- other_helpers.rb


Step

Given a widget


Step Deﬁnition

Given /^a widget$/ do
Given a widget #codes go here
end


Step Deﬁnition
Step Mother

Given /^a widget$/ do
Given a widget #codes go here
end


Outside-In


Write Scenarios


Steps are pending


Write Step Deﬁnition


Go Down A Gear


RSpec


RSpec

We ain’t got
no RSPEC!


RSpec, TestUnit, etc


Write Code Example
(Unit Test)


Make Example Pass


REFACTOR!!


Where Are we?


Continue until...


REFACTOR
and
REPEAT

features/manage_my_wishes.feature
Feature: manage my wishes

In order to get more stuff
As a greedy person
I want to manage my wish list for my family members to view

Scenario: add wish
Given I am logged in
When I make a quot;New carquot; wish
Then quot;New carquot; should appear on my wish list


Line # of scenario


I can has backtraze?
Given I am logged in #features/manage_my_wishes.feature:8


features/i_can_has_wishez_plz.feature

OH HAI: I CAN HAS WISHEZ PLZ

SO DAT I CAN HAS HUGS TIEM AN PLAY TIEM AN SLEEP TIEM AN NOM TIEM
AS NICE GREEDEE KITTEH
I CAN PLZ MANEGE TEH WISHEZ

MISHUN: MAK NEW WISH
GIVN I AM LOGGD IN
WEN I MAK quot;CHEEZBURGERquot; WISH
DEN I C quot;CHEEZBURGERquot; ON ME WISHEZ LIT


cucumber some.feature --language en-lol


features/step_deﬁnitions/user_steps.rb
Given /^I am logged in$/ do
@current_user = create_user(:email_confirmed => true)

end



end

Test Data Builder / Object Mother



end

Fixture Replacement, Fixjour, Factory Girl, etc
spec/ﬁxjour_builders.rb
Fixjour do
define_builder(User) do |klass, overrides|
klass.new(
:email => quot;user#{counter(:user)}@email.comquot;,
:password => 'password',
:password_confirmation => 'password'
)
end
end



visit new_session_path
fill_in quot;Emailquot;, :with => @current_user.email
fill_in quot;Passwordquot;, :with => valid_user_attributes[quot;passwordquot;]
click_button
end


Webrat / Awesomeness

click_button
end



click_button
end

features/support/env.rb
require 'webrat'

Webrat.configure do |config|
config.mode = :rails
end



click_button
end

features/support/env.rb
require 'webrat'

Webrat.configure do |config|
config.mode = :rails
end
Adapter



click_button
end

features/step_definitions/webrat_steps.rb
When /Î press quot;(.*)quot;$/ do |button|
click_button(button)
end
19 Steps Out-of-box
When /Î follow quot;(.*)quot;$/ do |link|
click_link(link)
end

When /Î fill in quot;(.*)quot; with quot;(.*)quot;$/ do |field, value|
fill_in(field, :with => value)
end


click_button
# make sure we have actually logged in- so we fail fast if not
session[:user_id].should == @current_user.id
end



click_button
controller.current_user.should == @current_user
end



Specify outcome, not implementation.
click_button
controller.current_user.should == @current_user
response.should contain(quot;Signed in successfullyquot;)
end



click_button
end


No route matches “/sessions/create” with
{:method=>:post} (ActionController::RoutingError)


I’m going to cheat...


I’m going to cheat...
$ gem install thoughtbot-clearance
$ ./script generate clearance
$ ./script generate clearance_features


features/step_deﬁnitions/wish_steps.rb
When /^I make a quot;(.+)quot; wish$/ do |wish|

end

Then /^(.+) should appear on my wish list$/ do |wish|

end



end


end

Regexp Capture -> Yielded Variable


visit quot;/wishesquot;
click_link quot;Make a wishquot;
fill_in quot;Wishquot;, :with => wish
click_button
end


end


click_button
end

response.should contain(quot;Your wish has been added!quot;)
response.should contain(wish)
end


click_button
end
No route matches “/wishes” with
{:method=>:get} appear on my wish list$/ do |wish|
Then /^(.+) should (ActionController::RoutingError)
response.should contain(quot;Your wish has been added!quot;)
response.should contain(wish)
end


conﬁg/routes.rb
ActionController::Routing::Routes.draw do |map|

map.resources :wishes


conﬁg/routes.rb


When I make a “New car” wish
uninitialized constant WishesController (NameError)


conﬁg/routes.rb


$./script generate rspec_controller new create


conﬁg/routes.rb


Could not find link with text or title or
id “Make a wish” (Webrat::NotFoundError)


app/views/wishes/index.html.erb
<%= link_to quot;Make a wishquot;, new_wish_path %>


<%= link_to quot;Make a wishquot;, new_wish_path %>

Could not find field: “Wish” (Webrat::NotFoundError)


click_button
end


click_button
end

app/views/wishes/new.html.erb
<% form_for :wish do |f| %>
<%= f.label :name, quot;Wishquot; %>
<%= f.text_field :name %>
<%= submit_tag quot;Make the wish!quot; %>
<% end %>


click_button
end

Location Strategy FTW!
app/views/wishes/new.html.erb
<% form_for :wish do |f| %>
<%= f.label :name, quot;Wishquot; %>
<%= f.text_field :name %>
<%= submit_tag quot;Make the wish!quot; %>
<% end %>


View

Controller


spec/controllers/wishes_controller_spec.rb
describe WishesController do
describe quot;POST / (#create)quot; do

end
end



it quot;should create a new wish for the user with the paramsquot; do
user = mock_model(User, :wishes => mock(quot;wishes associationquot;))
controller.stub!(:current_user).and_return(user)

user.wishes.should_receive(:create).with(wish_params)

post :create, 'wish' => {'name' => 'Dog'}
end
end
end


app/controllers/wishes_controller.rb
class WishesController < ApplicationController

def create
current_user.wishes.create(params['wish'])
end

end


before(:each) do
.....

it quot;should redirect the user to their wish listquot; do
do_post
response.should redirect_to(wishes_path)
end

end
end


def create
redirect_to :action => :index
end


View

Controller

Model


def create
end

undefined method `wishes` for #<User:0x268e898>
(NoMethodError)


def create
end

$./script generate rspec_model wish
name:string user_id:integer


app/models/wish.rb
class Wish < ActiveRecord::Base
belongs_to :user
end

app/models/user.rb
class User < ActiveRecord::Base
include Clearance::App::Models::User
has_many :wishes
end


app/models/wish.rb
class Wish < ActiveRecord::Base
belongs_to :user
end

app/models/user.rb
Then “New <car” should appear on my wish
class User ActiveRecord::Base
include Clearance::App::Models::User
has_many the following element’s content to include
expected:wishes
“Your wish has been added!”
end


it quot;should notify the user of creation via the flashquot; do
do_post
flash[:success].should == quot;Your wish has been added!quot;
end


do_post
end

def create
flash[:success] = quot;Your wish has been added!quot;
end


do_post
end

Then “New car” should appear on my wish
expected the following element’s content to include
def create
“New car”
flash[:success] = quot;Your wish has been added!quot;
end


describe quot;GET / (#index)quot; do
def do_get
get :index
end

it quot;should assign the user's wishes to the viewquot; do
do_get
assigns[:wishes].should == @current_user.wishes
end

end


def index
@wishes = current_user.wishes
end


| Laptop | Thomas |

Given /^the following wishes exist$/ do |table|
table.hashes.each do |row|
member = User.find_by_name(row[quot;Family Memberquot;]) ||
create_user(:name => row[quot;Family Memberquot;])

member.wishes.create!(:name => row[quot;Wishquot;])
end
end


Feature: Addition
In order to avoid silly mistakes
As a math idiot
I want to be told the sum of two numbers

Scenario Outline: Add two numbers
Given I have entered <input_1> into the calculator
And I have entered <input_2> into the calculator
When I press <button>
Then the result should be <output> on the screen

Examples:
| input_1 | input_2 | button | output |
| 20 | 30 | add | 50 |
|2 | 5 | add | 7 |
|0 | 40 | add | 40 |


Steps Within Steps
When /^I view the wish list for quot;(.+)quot;$/ do |user_name|
Given quot;I am logged inquot;
visit quot;/wishes/#{user_name}quot;
end


Helpers - Ruby FTW
When /^I view the wish list for quot;(.+)quot;$/ do |user_name|
login_as(create_user)
visit quot;/wishes/#{user_name}quot;
end



def login_as(user)
fill_in quot;Emailquot;, :with => user.email
click_button
end

login_as(@current_user)
end



def login_as(user)
“Every time you monkeypatch
click_button
Object, a kitten dies.”
end

login_as(@current_user)
end

http://seanohalpin.github.com/unobtrusive-metaprogramming/unobtrusive-metaprogramming.html


module UserHelpers
def login_as(user)
click_button
end
end


module UserHelpers
def login_as(user)
click_button
end
end

World { |world| world.extend UserHelpers }


I can skp teh
unit testz?


Acceptance Tests Unit Tests

Application Level Object Level- Isolated!
For Customers For developers
Slow FAST! (should be at least)
Good conﬁdence - Tighter Feedback Loop
Prevent against More about design!!!!!!!!!!!!
regression

Will need both gears!
Some things are easier to
test at the application
level and vice-versa.


SRSLY?
Model specs,
Controller Specs,
and view specs!?


More tests ==
More Maintenance


Test Value =
Design +
Documentation +
Defence
(regression)


if test.value > test.cost
Suite.add(test)
end


KTHXBYE!
BenMabey.com
github.com/bmabey
Twitter: bmabey
IRC: mabes

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