Testing with RSpec (RubyDay 2011)

Simone [email protected]

twitter: @weppos

Testing with RSpec

2011

Monday, June 20, 2011

Me.about(:robodomain)


Me.about(:ifad)


describe RSpec, "Agenda"


Testing


TDD seems to be applicable in various domains and can

significantly reduce the defect density of developed

software without significant productivity reduction of the

development team.

http://www.infoq.com/news/2009/03/TDD-Improves-

Quality


http://www.infoq.com/news/2009/03/TDD-Improves-Quality




The pre-release defect density of the four products,

measured as defects per thousand lines of code,

decreased between 40% and 90% relative to the

projects that did not use TDD. The teams' management

reported subjectively a 15–35% increase in initial

development time for the teams using TDD, though the

teams agreed that this was offset by reduced

maintenance costs.


$ rspec

http://relishapp.com/rspec

https://github.com/rspec


http://relishapp.com/rspec/

http://relishapp.com/rspec/



describe RSpec, "Features"


Readabilitydescribe Whois::Client do describe "#initialize" do it "accepts a timeout setting with a value in seconds" do klass.new(:timeout => 100).timeout.should == 100 end

it "accepts a timeout setting with a nil value" do klass.new(:timeout => nil).timeout.should be_nil end end

describe "#query" do it "detects email" do expect { klass.new.query("[email protected]") }.to raise_error(Whois::ServerNotSupported) end endend


Isolationdescribe UsersController do context "when logged as administrator" do before(:each) do log_in_as @admin = Factory(:user, :username => "admin") end

context "with a bunch of users" do before(:each) { @users = 3.times.map { Factory(:user) } }

describe "GET index" end

context "with no users" do describe "GET new" describe "POST create" end

describe "with a user" do before(:each) { @user = Factory(:user) }

describe "GET show" end endend


Extensibledescribe 9 do it "should be a multiple of 3" do (9 % 3).should == 0 endend

# vs

RSpec::Matchers.define :be_a_multiple_of do |expected| match do |actual| actual % expected == 0 endend

describe 9 do it "should be a multiple of 3" do 9.should be_a_multiple_of(3) endend


describe RSpec, "Syntax"


Basic Exampledescribe String do describe "#upcase" do it "returns the original string converted to uppercase" do "hello".upcase.should == "HELLO" end

it "returns a String" do "hello".upcase.should be_a(String) end

it "does not change the original string" do string = "hello" string.upcase string.should_not == "HELLO" end endend


context / describedescribe "something" do context "in one context" do it "does one thing" do end end

context "in another context" do it "does another thing" do end endend


before / afterdescribe "before / after" do before(:each) {} before(:all) {} before(:suite) {}

after(:each) {} after(:all) {} after(:suite) {}end

# Before and after blocks are called in the following order:# # before suite# before all# before each# after each# after all# after suite


before / afterdescribe "before / after" do before(:each) do @hash = {} end

it "does something" do @hash[:key] = "value" @hash[:key].should_not be_empty endend


let$count = 0describe "let" do let(:count) { $count += 1 }

it "memoizes the value" do count.should == 1 count.should == 1 end

it "is not cached across examples" do count.should == 2 endend


Implicit subjectdescribe Array do describe "when first created" do it "should be empty" do subject.should eq([]) end endend


subjectdescribe Array do subject { [1,2,3] }

describe "with some elements" do it "should have the prescribed elements" do subject.should == [1,2,3] end endend


expectdescribe Integer do describe "#/" do it "raises ZeroDivisionError when divisor is 0" do lambda do 1 / 0 end.should raise_error(ZeroDivisionError) end endend

# vs

describe Integer do describe "#/" do it "raises ZeroDivisionError when divisor is 0" do expect { 1 / 0 }.to raise_error(ZeroDivisionError) end endend


Shared Behaviorsshared_examples "a collection" do let(:collection) { described_class.new([7, 2, 4]) }

context "initialized with 3 items" do it "says it has three items" do collection.size.should eq(3) end end

describe "#include?" do context "with an an item that is in the collection" do it "returns true" do collection.include?(7).should be_true end end

context "with an an item that is not in the collection" do it "returns false" do collection.include?(9).should be_false end end endend


Shared Behaviorsdescribe Array do it_behaves_like "a collection"end

describe Set do it_behaves_like "a collection"end


pendingdescribe Hash do it "adds a key" do { :key => "value" }[:key].should == "value" end

it "does something unknown"

it "does something buggy" do pending "This method is buggy" endend

describe Integer do before(:each) { pending }

it "computes 1 + 1" do (1 + 1).should == 2 end

it "computes 1 - 1" do (1 - 1).should == 0 endend


pendingdescribe "an example" do xit "is pending using xit" do true.should be(true) endend

describe "an example" do it "checks something" do (3+4).should == 7 end pending do "string".reverse.should == "gnirts" endend


Metadatadescribe "something", :this => { :is => :arbitrary } do it "does something", :and => "so is this" do # ... endend

RSpec.configure do |c| c.filter_run_excluding :ruby => lambda {|version| !(RUBY_VERSION.to_s =~ /^#{version.to_s}/) }end describe "something" do it "does something", :ruby => 1.8 do # .... end it "does something", :ruby => 1.9 do # .... endend


MetadataRSpec.configure do |c| c.filter_run :focus => trueend

describe "something", :focus => true do it "does something" do # .... endend

RSpec.configure do |c| c.filter_run_excluding :slow => trueend

describe "something", :slow => true do it "does something" do # .... endend


describe RSpec, "Integration"


RSpec


describe AccountsController do describe "GET show" do before(:each) do get :show end

it { should respond_with :success } it { should render_template "accounts/show" }

it "assigns user" do assigns(:user).should == @user end endend

RSpec# Gemfilegroup :development, :test do gem 'rspec-rails', '~> 2.6.0'end

spec folder


RSpecRSpec.configure do |config| config.include Rack::Test::Methodsend

describe Tremonti::Application do def app Tremonti::Application end

describe "/" do it "should respond with 200" do get "/" last_response.should be_ok last_response.body.should == "Hello from RoboFinance!" end endend

rack-test


RSpec MochaRR

RSpec.configure do |config|

# == Mock Framework # # If you prefer to use mocha, flexmock or RR, uncomment the appropriate line: # config.mock_with :mocha # config.mock_with :flexmock # config.mock_with :rr

end


RSpec Factoriesdescribe BillingCharge do subject { Factory.build(:billing_charge) }

describe "associations" do it { should belong_to(:user) } end

describe "validations" do it "is valid with factory" do Factory.build(:billing_charge).should be_valid end

it { should validate_presence_of(:user_id) }

it { should validate_format_of(:period).with('2010-02') } it { should validate_format_of(:period).not_with('201002') } it { should validate_format_of(:period).not_with('2010') } endend


describe RSpec, "Best Practices"


describe vs contextdescribe ".guess" do it "recognizes tld" do s = Whois::Server.guess(".com") s.should be_a(Whois::Server::Adapters::Base) s.type.should == :tld end

context "when the input is a tld" do it "returns a IANA adapter" do Whois::Server.guess(".com").should == Whois::Server.factory(:tld, ".", "whois.iana.org") end end

context "when the input is a domain" do it "lookups definitions and returns the adapter" do Whois::Server.guess("example.test").should == Whois::Server.factory(:tld, ".test", "whois.test") end endend


it vs specifydescribe User do before do @user = User.new :username => 'weppos' end

it "is not an administrator" do @user.should_not be_admin endend

# vs.

describe User do let(:user) do User.new :username => 'weppos' end

specify do user.should_not be_admin endend


shoulddescribe "#order_price" do it "should be a Money" do # ... end

it "should return nil when amount is blank" do # ... endend

# vs

describe "#order_price" do it "is a Money" do # ... end

it "returns nil when amount is blank" do # ... endend


context vs itdescribe Hash, "#size" do it "returns 0 when the Hash is empty" do end

it "returns the number of elements when the Hash is not empty" do endend

# vs

describe Hash, "#size" do context "when the Hash is empty" do it "returns 0" do end end

context "when the Hash is not empty" do it "returns the number of elements" do end endend


Instance vs Class methodsdescribe Time do describe ".parse" do it "converts given string into a Time" do Time.parse('2010-06-12').should == Time.mktime(2010, 06, 12) end end

describe "#to_i" do it "returns the timestamp corresponding to the Time object" do t = Time.mktime(2010, 06, 12) t.to_i.should == 1276293600 end endend


spec_helper.rb & /support


Demo Time


Choose the right tool...


... and Test!


Thanks!


Testing with RSpec (RubyDay 2011)

Technology

Transcript of Testing with RSpec (RubyDay 2011)