Testing + Buenas Prácticas Testing + Buenas Prácticas Frameworks: RSpec vs Minitest Fixtures Debugging Errores comunes con Rails Gemas útiles para trabajar Consultas Cierre Ciclo de Testing Ciclo de Testing Testing Frameworks Qué framework elegir? Test::Unit Minitest RSpec otros... Testing Frameworks 7 Reasons I'm sticking with minitest and fixtures in Rails Testing Frameworks https://dhh.dk/2014/tdd-is-dead-long-live-testing.html Testing Frameworks RSpec rspec-core rspec-expectations rspec-mocks Y si usamos Rails: rspec-rails Cheatsheet http://kerryb.github.io/iprug-rspec-presentation/ Aclaración El slide anterior usa una sintaxis vieja En lugar de: (2 + 2).should == 4 Se debe usar: expect(2 + 2).to be == 4 Ejemplo RSpec.describe 'MyClass' do context "when conditions" it "does something" do obj = MyClass.new expect(obj.some_method).to eq "Something" end end end Expectations expect(2 + 2).to eq 4 expect(2 + 2).to_not eq 5 Matchers # Igualdad expect(actual).to eq expected # Identidad expect(actual).to be expected # Comparación expect(actual).to be >== expected expect(actual).to be_within(delta).of(expected) # Expresiones Regulares expect(actual).to match(/expression/) Matchers # Errores / Excepciones expect { ... }.to raise_error expect { ... }.to raise_error(ErrorClass) expect { ... }.to raise_error("message") expect { ... }.to raise_error(ErrorClass, "message") # Verdad / Falsedad expect(actual).to be_truthy # passes if actual is truthy (not nil or false) expect(actual).to be true # passes if actual == true expect(actual).to be_nil # passes if actual is nil expect(actual).to_not be_nil # passes if actual is not nil # Predicate matchers expect(actual).to be_xxx # passes if actual.xxx? expect(actual).to have_xxx(:arg) # passes if actual.has_xxx?(:arg) Red, Green, Refactor... Bloques before/after Bloques let/let! Context before block RSpec.describe 'Hello world' do before do @hw = HelloWorld.new end it "has a default greeting" do expect(@hw.say_hi).to eq "Hello World" end it "can receive a param" do expect(@hw.say_hi "there!").to eq "Hello There!" end end before block before(:each) before(:all) after(:each) after(:all) let RSpec.describe 'Hello world' do let(:hw) { HelloWorld.new } it "has a default greeting" do expect(hw.say_hi).to eq "Hello World" end it "can receive a param" do expect(hw.say_hi "there!").to eq "Hello There!" end end let + context RSpec.describe 'Let inside Context' do context "as a User" do let (:user) { User.new } # ... end context "as an Admin" do let (:user) { Admin.new } # ... end end let lazy evaluation memoised on first use reseted between examples let! siempre se inicializa Mock (double) require "rspec/mocks/standalone" obj = double(:book) # => #<Double "book"> obj = double(:book, pages: 250) obj.pages # => 250 class User attr_accessor :username end # `instance_double` valida contra objetos reales user = instance_double("User", :admin, username: 'admin') # OK user = instance_double("User", :admin, email: 'admin@example.com') # Error Method Stubs allow(book).to receive(:title) { "The RSpec Book" } allow(book).to receive(:title).and_return("The RSpec Book") allow(book).to receive_messages( title: "The RSpec Book", subtitle: "Behaviour-Driven Development with RSpec, Cucumber, and Friends") Message Expectations Similares a un method stub, pero el test espera que el método sea llamado. (En caso contrario, falla) # Stub person = double("person") allow(Person).to receive(:find) { person } # Expectation person = double("person") expect(Person).to receive(:find) { person } rspec-rails Generators Transactions Directory Structure Tipos de specs Model Controller Request Feature View Helper Mailer Routing Job System Model spec RSpec.describe Post, :type => :model do # ... end Controller spec render_template expect(response).to render_template(:new) # wraps assert_template redirect_to expect(response).to redirect_to(location) # wraps assert_redirected_to have_http_status expect(response).to have_http_status(:created) System spec RSpec.describe "Widget management", :type => :system do it "enables me to create widgets" do visit "/widgets/new" fill_in "Name", :with => "My Widget" click_button "Create Widget" expect(page).to have_text("Widget was successfully created.") end end Transacciones FactoryBot Fixtures Pros y Contras Fixtures # This is a YAML comment david: name: David Heinemeier Hansson birthday: 1979-10-15 profession: Systems development steve: name: Steve Ross Kellock birthday: 1974-09-27 profession: guy with keyboard Fixtures associations # In fixtures/categories.yml about: name: About # In fixtures/articles.yml first: title: Welcome to Rails! body: Hello world! category: about Fixtures - modo de uso # this will return the User object for the fixture named david users(:david) # this will return the property for david called id users(:david).id FactoryBot - definición FactoryBot.define do factory :user do first_name { "John" } last_name { "Doe" } admin { false } end end FactoryBot - uso # Returns a User instance that's not saved user = build(:user) # Returns a saved User instance user = create(:user) # Returns a hash of attributes that can be used to build a User instance attrs = attributes_for(:user) # Returns an object with all defined attributes stubbed out stub = build_stubbed(:user) # Passing a block to any of the methods above will yield the return object create(:user) do |user| user.posts.create(attributes_for(:post)) end Faker require 'faker' Faker::Name.name #=> "Christophe Bartell" Faker::Internet.email #=> "kirsten.greenholt@corkeryfisher.info" # Ejemplo FactoryBot.define do factory :user do first_name { Faker::Name.name } last_name { Faker::Name.last_name } admin { false } end end Debugging pry irb debugger rails log Errores comunes con Rails No reiniciar el server (Gemfile / Routes) GodObject / Fat models (ej: User) Demasiada logica en los Controllers Queries en las vistas No usar scopes N+1 consultas Gemas útiles para desarrollo: pry awesome_print hirb letter_opener Debugging: better_errors pry-rails web-console Testing: factory_bot faker timecop vcr webmock database_cleaner Procesos en background: sidekiq rescue delayed_job Otras gemas útiles: curb rest-client pundit cancancan draper Otras gemas útiles: dotenv rails_12factor rubocop dependabot Consultas Gracias Contacto: joaquin@wecode.io