Rails testing with RSpec, Capybara and RSpec-Candy

#test for editing
#setup on the command line
gem install rspec
rspec --init

#add to gemfile:
group :test, :development do
  gem 'rspec-rails'
end

# on the command line
bundle install
rails generate rspec:install

#create .rspec and save in the file the following:
-- color
-- format documentaion

# feature Specs:

feature Page_Name do
  scenario '' do
    it '' do
    end
  end
end

# model specs:
# unit Tests:

  describe Model_Name do
    describe 'Method_name' do
      it '' do
      end
    end
  end

# before the method_name
# '#' class methods
# '.' instance methods

# matchers:

# for text content -
expect(page).to have_content('Privacy Policy')

# for CSS -
expect(page).to have_css('.support-form')
# Note . = class, # = id

# for selector e.g. <footer> or <a> -
expect(page).to have_selector('footer')

# match a regular expression -
animal.type should_match(/hamster/)

# counting number -
human.hands.count should == 2
human.should have(2).hands
human.should have_at_least(2).hands
human.should have_at_most(2).hands
human.should be_within(1).of(10)

# monitoring change -
expect { human.save }.to change { Human.count }.by(1)
expect { human.save }.to change { Human.count }.by(1).from(1)
expect { human.save }.to change { Human.count }.by(1).to(2)

# raise_exception -
expect { human.save }.to raise_error (ActiveRecord::RecordInvalid)

# for links - 
expect(page).to have_link('Privacy Policy', href: "Privacy_Policy.pdf")

# for testing type -
expect(user).to be_a(Hash)

# testing collections -
Content.find_contents_for_user(user.id).should include content1, content2 #does not care about order
Content.find_contents_for_user(user.id).should eq content1
Content.find_contents_for_user(user.id).should be content1
expect(User.most_liked(1)).to start_with(user)

# method testing -
human.should respond_to(alive?)

# other matchers -
human.should exist
human.should satisfy { |human| human.hungry? }
creature.should be_kind_of(Human)
human.name.should be_an_instance_of(String)

# testing callbacks -
# Use 'RSpec-candy' Gem

 describe Content, '#after_create' do
    it_should_run_callbacks :set_short_url, :set_new_content, :send_notification
  end
  
# testing with one subject allows you define the subject and then use it {} statements
subject { content }
it { should be_valid } or it { should_not be_valid }

# implicit subject/receiver
# if you use a class name in your describe block i.e. 'describe Human do' you have five further options:

subject.should respond_to(:name)
OR
should respond_to(:name)

describe Human do
  it 'responds to name do
    should respond_to(:name)
  end
end

describe Human do
  it 'responds to name' { should respond_to(:name) }
end

describe Human do
  it { should respond_to(:name) }
end

describe Human do
  its(:name) { should == 'Eric' }
end

# more then one subject use let and define subject in block

context 'poor human' do
  let(:human) { Human.new(income: poor, clothes: [knackered]) }
  let(:knackered) { Clothes.new(name: 'knackered') }
  subject { human }
  
  its (:clothes) { should include(knackered) }
  
  it 'can wear its knackered clothes' do
    human.wear(knackered).should == true
  end
end

#newer RSpec allow you to combine the the subject and let line

subject(:human) { Human.new(income: poor, clothes: [knackered]) }

#Lazy evaluation and Let! - let does not create the object until the rest calls it, Let! creates it and puts it in the database

it "creates a human" { Human.count == 1 } # this would fail if the human was created with let but not Let!

# debugging tests:

# use 'byebug' Gem, add to Gemfile and bundle install
# insert the word byebug at the top of the it '' block
# use puts to output variables 
# use sleep(30) to check the page
# use 'rails console' to understand the data that goes in and out

# good Resources:

e-book - http://everydayrails.com
webpage - http://betterspecs.org
Codeschool - $29 per month - has four courses - https://www.codeschool.com/courses/testing-with-rspec
Rails4 in Action - http://www.manning.com/bigg2/
Railscast 158 - Factories - http://railscasts.com/episodes/158-factories-not-fixtures-revised
Railscast 275 - How I test - http://railscasts.com/episodes/275-how-i-test
Railscast 257 - Request Specs and Capybara - http://railscasts.com/episodes/275-how-i-test
webpage - http://railsadventures.wordpress.com/2013/09/25/11-steps-to-make-your-rspec-specs-awesome/
webpage - http://gaslight.co/blog/6-ways-to-remove-pain-from-feature-testing-in-ruby-on-rails

# RSpec Maintainers:
http://www.andylindeman.com
http://myronmars.to/n/dev-blog