This is a presentation which shows how to unit test with rspec, factory girl in a rails project

1. Rspec and Rails
Abraham Kuri

2. Table of Contents
01 Rails setup
02 Expectations & Matchers
03 Shoulda & DRY Specs
04 Context & Describe blocks
05 Before block
06 Stub & Mock
07 Where to go next?

3. Rails Setup

4. Rails Setup

5. Rails Setup
$ rails new <app_name> --skip-test-unit

6. Rails Setup
$ rails new <app_name> --skip-test-unit
Gemfile:
group :test, :development do
gem 'rspec-rails'
gem "factory_girl_rails"
gem 'ffaker'
end

7. Rails Setup
$ rails new <app_name> --skip-test-unit
Gemfile:
group :test, :development do
gem 'rspec-rails'
gem "factory_girl_rails"
gem 'ffaker'
end

8. Rails Setup
$ rails new <app_name> --skip-test-unit
Gemfile:
group :test, :development do
gem 'rspec-rails'
gem "factory_girl_rails"
gem 'ffaker'
end

9. Rails Setup
$ rails new <app_name> --skip-test-unit
Gemfile:
group :test, :development do
gem 'rspec-rails'
gem "factory_girl_rails"
gem 'ffaker'
end
$ bundle install

10. Rails Setup
$ rails new <app_name> --skip-test-unit
Gemfile:
group :test, :development do
gem 'rspec-rails'
gem "factory_girl_rails"
gem 'ffaker'
end
$ bundle install
$ rails g rspec:install

11. Expectations & Matchers
‣ user_spec.rb

12. Expectations & Matchers
‣ user_spec.rb

13. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil
user.should_not == nil
end
end

14. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil
user.should_not == nil
end
end

15. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end

16. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end

17. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher

18. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher

19. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher

20. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher

21. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end

22. Expectations & Matchers
‣ user_spec.rb
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
it 'should not be valid without a name' do
user.name = nil modifier
user.should_not == nil
end
end matcher
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end

23. Other matchers

24. Other matchers
user.name.should == "Abraham"
user.friends.should > 3
user.alive.should == true
user.alive.should_not == false
user.girlfriend.should == nil
user.should be_alive
have(n)
user.friends.should include(other_user) have_at_least(n)
have_at_most(n)
user.should have(2).arms

25. Other matchers
user.name.should == "Abraham"
user.friends.should > 3
user.alive.should == true
user.alive.should be_true
user.alive.should_not == false
user.girlfriend.should == nil
user.should be_alive
have(n)
user.friends.should include(other_user) have_at_least(n)
have_at_most(n)
user.should have(2).arms

26. Other matchers
user.name.should == "Abraham"
user.friends.should > 3
user.alive.should == true
user.alive.should be_true
user.alive.should_not == false
user.alive.should_not be_false
user.girlfriend.should == nil
user.should be_alive
have(n)
user.friends.should include(other_user) have_at_least(n)
have_at_most(n)
user.should have(2).arms

27. Other matchers
user.name.should == "Abraham"
user.friends.should > 3
user.alive.should == true
user.alive.should be_true
user.alive.should_not == false
user.alive.should_not be_false
user.girlfriend.should == nil
user.alive.should be_nil
user.should be_alive
have(n)
user.friends.should include(other_user) have_at_least(n)
have_at_most(n)
user.should have(2).arms

28. Shoulda to the rescue

29. Shoulda to the rescue

30. Shoulda to the rescue
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end

31. Shoulda to the rescue
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end

32. Shoulda to the rescue
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end
it { should validate_presence_of(:name) }

33. Shoulda to the rescue
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end
it { should validate_presence_of(:name) }
it { should validate_uniqueness_of(:email) }
it { should have_many(:friends).through(:friendship) }

34. Shoulda to the rescue
describe User do
let(:user) { FactoryGirl.create(:user) }
subject { user }
its(:name) { should_not be_nil }
end
it { should validate_presence_of(:name) }
it { should validate_uniqueness_of(:email) }
it { should have_many(:friends).through(:friendship) }
it { should belong_to(:user)}

35. Context & Describe Blocks

36. Context & Describe Blocks
describe User do
describe 'when sleep' do
it 'snores'
describe 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end

37. Context & Describe Blocks
describe User do
describe 'when sleep' do
it 'snores'
describe 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end

38. Context & Describe Blocks
describe User do
describe 'when sleep' do
it 'snores'
describe 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end Use context instead of describe

39. Context & Describe Blocks
describe User do
describe 'when sleep' do
it 'snores'
describe 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end Use context instead of describe
describe User do
context 'when sleep' do
it 'snores'
context 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end

40. Context & Describe Blocks
describe User do
describe 'when sleep' do
it 'snores'
describe 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end Use context instead of describe
describe User do
context 'when sleep' do
it 'snores'
context 'with a soft pillow' do
it 'still snores'
it 'have good dreams'
end
end
end

41. Before block

42. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end

43. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end

44. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY

45. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do

46. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do

47. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do

48. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }

49. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end

50. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }

51. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }
its(:friend_names) { should == user.friends.map(&:name) }

52. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }
its(:friend_names) { should == user.friends.map(&:name) }
end

53. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }
its(:friend_names) { should == user.friends.map(&:name) }
end
end

54. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }
its(:friend_names) { should == user.friends.map(&:name) }
end
end

55. Before block
describe 'friends names' do
context 'when has friends' do
it 'should have 3 friends' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.should have(3).friends
end
it 'should return friend names' do
3.times { user.friends << FactoryGirl.create(:friend) }
user.friend_names.should == user.friends.map(&:name)
end
end
end Let’s be more DRY
describe 'friends names' do
context 'when has friends' do
before do
3.times { user.friends << FactoryGirl.create(:friend) }
end
it { should have(3).friends }
its(:friend_names) { should == user.friends.map(&:name) }
end
end Much better

56. Stubs & Mocking

57. Stubs & Mocking
‣ Stubs
For replacing a method with code that
return a specified result

58. Stubs & Mocking
‣ Stubs
For replacing a method with code that
return a specified result
‣ Mocks
A stub with an expectations that the
method gets called

59. Stub it out

60. Stub it out
app/models/user.rb
class User < ActiveRecord::Base
has_one :stomach
def feed_stomach
stomach.feed(self)
self.status = "full"
end
end

61. Stub it out
User
feed_stomach
app/models/user.rb
class User < ActiveRecord::Base
has_one :stomach
def feed_stomach
stomach.feed(self)
self.status = "full"
end
end

62. Stub it out
User
feed_stomach
app/models/user.rb
class User < ActiveRecord::Base
has_one :stomach
def feed_stomach
stomach.feed(self)
self.status = "full"
end
end

63. Stub it out
User Stomach
feed_stomach def feed(*args)
return nil
end
app/models/user.rb
class User < ActiveRecord::Base
has_one :stomach
def feed_stomach
stomach.feed(self)
self.status = "full"
end
end

64. Stub it out
User Stomach
feed_stomach def feed(*args)
return nil
end
user.stomach.stub(:feed_stomach)
app/models/user.rb
class User < ActiveRecord::Base
has_one :stomach
def feed_stomach
stomach.feed(self)
self.status = "full"
end
end

65. Complete spec

66. Complete spec
def feed_stomach
stomach.feed(self)
self.status = "full"
end

67. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
We need to test that feed is called

68. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
We need to test that feed is called

69. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
We need to test that feed is called

70. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
We need to test that feed is called

71. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
We need to test that feed is called

72. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
We need to test that feed is called

73. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
We need to test that feed is called

74. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
user.feed_stomach
We need to test that feed is called

75. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
user.feed_stomach
user.status.should == "full"
We need to test that feed is called

76. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
user.feed_stomach
user.status.should == "full"
end
We need to test that feed is called

77. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
user.feed_stomach
user.status.should == "full"
end
end
We need to test that feed is called

78. Complete spec
def feed_stomach
stomach.feed(self)
/spec/models/user_spec.rb self.status = "full"
end
describe User do
let(:user) { FactoryGirl.create(:user) }
describe '#feed_stomach' do
it 'set the status to full' do
user.stomach.stub(:feed)
user.feed_stomach
user.status.should == "full"
end
end
end We need to test that feed is called

79. Mocha flavor

80. Mocha flavor
/app/models/user.rb
def fb_friends_ids
user = FbGraph::User.me(self.token)
user.friends.map { |o| o.raw_attributes[:id] }
end

81. Mocha flavor
/app/models/user.rb
["1", "45", "987"]
def fb_friends_ids
user = FbGraph::User.me(self.token)
user.friends.map { |o| o.raw_attributes[:id] }
end

82. Mocha flavor
/app/models/user.rb
["1", "45", "987"]
def fb_friends_ids
user = FbGraph::User.me(self.token)
user.friends.map { |o| o.raw_attributes[:id] }
end
/app/specs/user_spec.rb

83. Mocha flavor
/app/models/user.rb
["1", "45", "987"]
def fb_friends_ids
user = FbGraph::User.me(self.token)
user.friends.map { |o| o.raw_attributes[:id] }
end
/app/specs/user_spec.rb
it 'calls the Facebook Graph to get friends' do
FbGraph::User.should_receive(:me).with(user.token)
.and_return(["1", "45", "987"])
user.fb_friends_ids
end
stubs the method + expectation with correct
param
return value

84. Mocha flavor
/app/models/user.rb
["1", "45", "987"]
def fb_friends_ids
user = FbGraph::User.me(self.token)
user.friends.map { |o| o.raw_attributes[:id] }
end
/app/specs/user_spec.rb
it 'calls the Facebook Graph to get friends' do
FbGraph::User.should_receive(:me).with(user.token)
.and_return(["1", "45", "987"])
user.fb_friends_ids
end
stubs the method + expectation with correct
param
return value

85. Where to go next?
http://rspec.info/
https://github.com/rspec/rspec
https://github.com/thoughtbot/shoulda
http://eggsonbread.com/2010/03/28/my-rspec-
best-practices-and-tips/
http://www.rubyinside.com/how-to-rails-3-and-
rspec-2-4336.html

86. Rspec & Rails
Abraham Kuri